Building our energy future

National Grid plc Annual Report and Accounts 2024/25

At National Grid, we are driven by our purpose: to bring energy to life

Our aim is to be at the heart of a secure, affordable and clean energy future. We work with the wider energy industry, governments, regulators,

and the customers and communities we serve to deliver this vision.

Demand for electricity is expected to increase significantly through the electrification of heat and transport and the energy needs of advances in technology such as artificial intelligence. Innovation in electricity generation, including in renewables, storage and nuclear, is driving significant change in where and how energy is produced. There is significant innovation in the hardware and software we use to design, build, operate and maintain the energy networks we own.

As National Grid, our role is to deliver the network infrastructure and energy solutions required to meet the needs of our customers and stakeholders with this transition.

Our residential and commercial customers want access to clean, secure and affordable energy, delivered safely and reliably across our networks.

Energy generators and storage operators rely on our networks to move energy to the homes and businesses who need it.

Our governments and regulators expect us to deliver network infrastructure safely, reliably and affordably. They want our networks to support economic growth and emissions reduction targets.

Our investors expect us to deliver an attractive proposition, generating shareholder value through dividends and asset growth.

Across the energy sector, governments, regulators, financiers, suppliers and customers are all playing their part in delivering the changes needed. We play an important role and we continue to strengthen our relationships with key stakeholders. We engage local communities on our projects, while working with governments, regulators and our supply chain to deliver vital energy projects at pace.

This time last year we announced an unprecedented level of investment in our networks in the UK and US - c.£60 billion over five years, nearly doubling our investment from the previous period. Since then, we have scaled up our operations to deliver this level of investment in ground-breaking projects that will expand our networks. Delivery is well under way with a record £9.85 billion in capital investment in the year.

But it's not just about scale. It is about how we deliver too. We are building a culture of innovation at National Grid to ensure we make the best use of the networks we have and deliver new network infrastructure faster and more efficiently. We are working with our supply chain partners and leveraging the exciting new technologies being developed and invested in directly by our corporate venture capital arm, National Grid Partners.

2024/25 performance highlights

Strategic Report

2024/25 performance highlights National Grid at a glance Chair's statement

Chief Executive's review Our business model

Our business environment Our strategy

Succeeding with our strategy Key performance indicators Our stakeholders and s.172 Our Business Units

Internal control and risk management

Our principal risks and uncertainties

Responsible Business review TCFD

NFSI Statement Financial review Viability Statement

1

2

4

5

8

11

14

16

18

22

25

34

36

42

59

78

79

93

Corporate Governance

Chair's statement

Corporate governance overview Our Board

Group Executive Committee Key Board activities

Culture and workforce

engagement Board evaluation

Directors' induction, development and training People & Governance Committee report

Audit & Risk Committee report Safety & Sustainability Committee report

Finance Committee report Directors' Remuneration Report including the Directors'

Remuneration policy

96

98

99

103

104

106

108

109

110

112

119

120

121

Financial Statements

Statement of Directors' responsibilities

Independent Auditor's report Consolidated financial statements

Company financial statements

152

153

162

248

Additional Information

The business in detail

Internal control and risk factors Shareholder information

Other disclosures

Other unaudited financial information

Commentary on consolidated financial statements

Definitions and glossary of terms

Want more information?

256

262

270

276

279

295

297

302

‌Statutory operating profit Underlying operating profit

£4,934m £5,357m

10% y-on-y 2023/24: £4,475m

12% y-on-y 2023/24: £4,773m

Statutory earnings per share Underlying earnings per share

60.0p 73.3p

8% y-on-y 2023/24: 55.5p

2% y-on-y 2023/24: 72.1p

(rebased) (rebased)

Capital investment Asset growth

£9.85bn 9.0%

20% y-on-y 2023/24: £8.24bn -0.7% y-on-y 2023/24: 9.7%

Dividend per share

Network reliability

46.7p 99.9%

3% y-on-y 2023/24: 45.26p 2023/24: 99.9%

(rebased)

Lost time injury frequency rate per 100,000 hours worked

Scope 1 and 2 GHG emissions thousand ktCO2e

0.10

7.4

25% y-on-y 2023/24: 0.08 8.3% y-on-y 2023/24: 6.9

Employee engagement

Our most recent overall employee engagement index in our twice annual Grid:Voice survey was 80%.

Further reading Deloitte assured data Denotes information subject to

Throughout this report you can find links to further detail within this document.

limited assurance (see page 18for full definition).

PwC assured data Denotes information subject to limited assurance (see page 18 for full definition).

Online report Alternative performance measure

The PDF of our Annual Report and Accounts 2024/25 includes a full search facility. You can find the document by visiting our website nationalgrid.com/ investors/resources/reports-plc or by scanning the QR code below the contents list.

In addition to International Financial Reporting Standards (IFRS) figures, management also uses a number

of alternative measures to assess performance. Definitions and reconciliations to statutory financial information can be found on pages 279- 284. These measures are highlighted with the symbol opposite.

Online content Reporting currency

In this report there are QR codes you can scan to view further content

online. Simply open the camera app on your smartphone to scan the code.

Our financial results are reported in sterling. We convert our US business results at the weighted average exchange rate during the year, which for 2024/25 was $1.27 to £1 (2023/24: $1.26 to £1).

Read this Annual Report online

National Grid at a glance

‌A vital role in

transforming energy systems

UK

National Grid businesses play a vital role in energy systems, safely and reliably connecting millions of people to the energy they use, while investing for the future to power growth, resilience and the transition to a cleaner tomorrow.

Our businesses UK Electricity

Transmission

UK Electricity Distribution

Read more 25

What we do

Transmission networks transport energy over long distances at high voltage (in the case of electricity) and high pressure (in the case of gas) from where it is produced and onwards to distribution networks.

Distribution networks take high-voltage electricity and high-pressure gas from transmission networks and deliver it at lower voltage and reduced pressure to homes, businesses and industrial infrastructure.

Supply involves buying and then selling electricity and gas on to customers, with associated customer services.

Generation is the production of electricity from renewable, nuclear and fossil fuel sources.

Storage are technologies such as batteries and liquified natural gas that store energy.

(UK ET/NGET)

We own and operate the high-voltage electricity transmission network in England and Wales. This includes connecting new customers and delivering the major strategic infrastructure to enable a clean power grid.

(UK ED/NGED)

We own and operate the UK's largest electricity distribution network, serving customers in the East Midlands, West Midlands, South West and South Wales. This includes a Distribution System Operator (DSO) which is overseen by an independent panel.

Read more 9

Business split

31% 18%

2024/25 Regulatory asset value (RAV), rate base and other assets (% of Group)

2024/25 Underlying operating profit (% of Group)

27% 22%

2024/25 Capital investment (£bn) £3.0bn £1.4bn

Indicates an alternative performance measure

US International

New York (NY) New England

(NE)

National Grid Ventures (NGV)

Other activities

We own and operate electricity transmission and distribution networks across upstate New York. We also own and operate gas distribution networks in New York City and on Long Island.

We own and operate electricity transmission networks in Massachusetts, New Hampshire and Vermont. In Massachusetts, we also own and operate electricity and gas distribution networks.

We develop and operate large scale energy projects across the UK and US. They represent a broad mix of energy assets and businesses, including six electricity interconnectors between the UK and Europe, US competitive transmission, power generation, liquified natural gas (LNG) import and battery storage. National Grid Renewables and Grain LNG are classified as held for sale.

Primarily National Grid Partners, the corporate venture capital and innovation arm of National Grid, plus UK property, insurance and corporate activities.

27% 14% 7% 3%

27% 17% 7% -%

£3.3bn £1.8bn £0.4bn £-bn

Chair's statement

‌Evolving landscape

Whole-system planning, deployment of advanced technologies and strong controls over our processes are key to running a business fit for the future.

Dear fellow shareholder,

Power is essential to the modern world. But throughout my four decades in the energy industry, networks have been of little interest to consumers. They were simply there when we needed them, providing reliable service. However, a confluence of events and policies has now placed energy networks in the public eye.

The UK Government's bold mission to achieve clean power by 2030 requires a once-in-a-generation 'rewiring' of the country's infrastructure. The US, by contrast, is focused on energy as a key enabler of economic growth, with an emphasis on driving the AI revolution and reshoring of manufacturing.

Both approaches will require substantial new energy supplies and infrastructure. And, as we've seen with recent global power interruptions, it's not surprising that energy infrastructure is now a more visible part of the public discourse.

The debate boils down to resiliency and affordability.

Given all that's at stake, it's fair for the public to ask how National Grid is going to ensure continued high levels of reliability, particularly as power systems have increasing proportions of renewables in the mix. Understandably, as customers experience escalating energy costs, regulators want to be assured that National Grid will invest cost-effectively in modernising its systems. And, in the boardroom, independent directors provide a constructive challenge to our leadership as it

maps the path forward. Whole-system planning, deployment of advanced technologies and strong controls over our processes are key to running a business fit for the future.

National Grid's talented global workforce of more than 30,000 employees embraces the opportunities that come with change.

For almost ten years, we have been wisely guided by our CEO, John Pettigrew. On

1 May 2025, we announced that John will retire later this year after 35 years of service. I am grateful to have learned about National Grid's businesses through John's eyes and experience. He has been a wonderful

collaborator and an exceptional leader whose impact will be felt for years to come. On behalf of the Board, I extend to him

heartfelt appreciation.

Our Board succession planning process has been well embedded. As such, on 1 May, we also announced that Zoë Yujnovich, a global executive at Shell plc, will assume the chief executive role at National Grid on 17 November 2025. She comes with a diverse background in energy and natural resources, along with a proven record in capital delivery. We have a transition plan in place for the handover and the company will not miss

a beat.

The energy landscape is evolving, and so is National Grid. I feel confident that our committed workforce, inspired by John's example and newly led by Zoë, will serve our shareholders, customers and communities well in the times ahead. Thank you for your continued support.

Sincerely,

Paula Rosput Reynolds

Chair

14 May 2025

Final dividend of

30.88p

per share proposed to be paid on 17 July 2025

The 2025 Annual General Meeting (AGM) of National Grid plc will be held as a hybrid event at 11.00am on Wednesday 9 July 2025. More details on the arrangements for this year's AGM, including how to attend virtually, can be found at nationalgrid.com/investors

Chief Executive's review

‌Resilient, reliable networks

With our strategic focus on energy networks, we are delivering our £60 billion five-year plan at pace, building the next generation of infrastructure and solutions needed to meet accelerating demand for secure, affordable and clean energy.

Context in which we are operating

After 35 years at National Grid and nearly 10 years as CEO, I recently shared my decision to retire from the Group. It has been an immense honour for me to lead the company I joined as a graduate, and when I step down later this year, I will do so knowing that we are in a position of great strength. I also have every confidence that my successor, Zoë Yujnovich, is the right person to lead National Grid on the next stage of its journey.

We are living through a period of unprecedented change in the world, but also one of opportunity and growth. Resilient and reliable networks capable of meeting demand for secure, affordable and clean energy are essential to future prosperity, helping to create the industries and technologies of tomorrow, drive economic growth and support millions of jobs.

In the UK, the Government's mission for clean power by 2030 is an important part of its growth plans and aims to achieve at least 95% renewable energy by the end of the decade. This ambitious initiative includes major industry reforms across energy planning, connections, supply chains

and digitisation.

In the US, we have seen a shift at the federal level from a focus on climate to economic competitiveness and national security. At the state level, there is increasing focus on energy affordability and reliability, coupled with an ongoing debate on how to best achieve the transition to cleaner energy. At National Grid, we believe that strengthening and modernising our networks is the key to helping our regions attract investment and bolster security of supply, while continuing to reduce carbon emissions.

I'm pleased to say we've seen good progress in our push for policies that are essential for the energy transition and attract the investment needed to fund the networks of the future. This will be critical to ensuring we build the capacity and resilience needed in the energy system.

There is particular focus on this in the UK following the fire at our North Hyde substation and subsequent disruption at Heathrow Airport and the surrounding area. While transmission power was always available to Heathrow, we are committed to working closely with the National Energy System Operator and our other stakeholders to ensure any lessons are learned and that we prevent incidents like this from happening again.

Business highlights from the year

Against this backdrop, I'm hugely proud of all we've achieved over the past 12 months.

We're leading the industry in delivering the next generation of networks and energy solutions that will be fit for the 21st century.

Personal highlights for me include the progress we've made with our 17 ASTI projects and our ambitious £35 billion plan for the transmission network in England and

Wales, which we've now submitted to Ofgem. We've also secured seven new delivery partners through our £9 billion Great Grid Partnership and 10 more suppliers in our

£59 billion high voltage direct current (HVDC) framework. Together, these initiatives represent the biggest upgrade of the UK energy grid in a generation.

I'm also proud of the huge strides we've made through our UK Distribution System Operator in scaling up the benefits we've delivered for our stakeholders, consumers and the energy system in the last 12 months.

6 National Grid plc Annual Report and Accounts 2024/25

Chief Executive's review continued

We've made excellent progress in the US as well. Our $4 billion Upstate Upgrade in New York is on track, and we're delivering further gas mains replacement and network reinforcement across the state. In Massachusetts, our $2 billion Electric Sector Modernization Plan was approved by the regulator, and we achieved an important legislative milestone on permitting reform with the passage of the Massachusetts climate bill. We also agreed fair new rates for our downstate New York gas and Massachusetts electric businesses.

In our National Grid Ventures business, we've made significant progress with our pioneering LionLink interconnector. Once complete, it will provide another connection between the British and Dutch electricity grids, maximising our renewable energy resources, reducing reliance on fossil fuels, and reinforcing security of supply for Britain.

As with LionLink, innovation runs through everything we do, and National Grid Partners is an important part of that, investing in technologies that have game-changing potential for the future of energy. We have invested more than $500 million in startups to date and committed an additional $100 million for AI startups.

Finally, as part of our refocusing on networks, we have announced the sale of National Grid Renewables to Brookfield for $1.7 billion and launched the sale of our LNG facility at the Isle of Grain.

We have achieved all this while ensuring the safety and security of our networks, and the reliable flow of energy for millions of homes and businesses.

Read more:

Our business units pages 25- 33

Investment and delivering for shareholders

We successfully completed the £7 billion Rights Issue last Spring, an important part of our plan to invest around £60 billion. We are grateful for the support you, our shareholders, have shown as we undertake this historic investment.

Capital investment was a record £9.85 billion over the past year, in line with our plan and 20% higher than last year. This reflects the scale of activity across all our regulated businesses. We've delivered a strong performance, with underlying operating profit increasing 12% to £5.4 billion at constant currency, reflecting increased regulated revenues and flat controllable costs, and achieved through our focus on agreeing

the right regulatory frameworks and efficient delivery.

Five-year financial framework 2024/25 - 2028/29 announced 23 May 2024

Capital investment Group asset growth Underlying EPS

c.10%

CAGR1

6-8%

CAGR2

£60bn

Balance sheet and ratings Dividend and equity

Credit metrics maintained above current

rating thresholds3

Aim to grow dividend per share in line with

UK CPIH4

Regulatory gearing at 61% at March 2025, then trending back towards the high-60% range by the end of RIIO-T3

Net Rights Issue proceeds of £6.8bn in 2024/25

c.£51bn

Green, directly into the decarbonisation of energy networks, aligned to EU Taxonomy

UK ET c.£23bn

UK ED c.£8bn

New England c.£11bn

New York c.£17bn

NGV c.£1bn

Use of hybrid debt Continued use of scrip dividend

Strategic Report Corporate Governance Financial Statements Additional Information 7

National Grid is now embarking on an exciting new phase of growth with an attractive investor proposition underpinned by high quality asset growth, strong earnings growth, and an inflation protected dividend.

Empowering colleagues, customers and communities

We are working to balance the investment required to deliver affordable energy for our customers with the reality that many are struggling with a high cost of living. To help, we have announced a new £13.8 million Grid for Good Energy Affordability Fund. This will run for three years, with donations to charities and organisations providing immediate financial relief to families and communities in need on both sides of the Atlantic.

In the US, we continue to improve the reliability of our customer systems. We have launched an updated mobile app, enhanced outage communications, and made it easier for customers to update their communication preferences. These improvements, amongst others, will help us to better connect customers with ways to save energy, manage their bills and easily access assistance.

Our deep commitment to local communities includes our ongoing rapid response teams. In September 2024, nearly 150 of our crews travelled to storm-ravaged Tennessee, Virginia and West Virginia to assist with safety and recovery from Hurricane Helene. In December 2024, Storm Darragh brought major disruption across the UK. It was one of the biggest storms to impact our network in decades and I'm proud of our teams who managed to get 95% of the over 700,000 customers impacted back on supply within 48 hours.

Looking ahead

After another year of strong performance, we have a solid platform to build on. We are now squarely focused on delivering for our customers and communities, building and operating the infrastructure needed to meet accelerating demand at the right speed and scale for the lowest possible cost.

As my time with National Grid draws to a close, we are well positioned to take advantage of the significant growth opportunities ahead. It has been the privilege of my life to lead this company over the past decade and I'm incredibly proud of all we've achieved in that time. This is down to the unwavering commitment of our 30,000 dedicated colleagues and their relentless focus on delivering for our customers. It is our people that make this organisation so special. It is also our people who give me great confidence that, when I hand the reins to my successor Zoë in November, National Grid will continue to go from strength-to-strength.

John Pettigrew

Chief Executive 14 May 2025

8 National Grid plc Annual Report and Accounts 2024/25

Our business model

‌Building our energy future

We are playing a key role in delivering the energy systems

of the future, working alongside partners for the benefit of our customers, communities, and wider society.

Our resources

Physical assets Efficient financial capital

Our network assets are critical infrastructure. They are large and built to last. We continuously invest to maintain and upgrade them to ensure safe and reliable service, integrate new sources of power, and meet new demand.

We fund our business through a combination of equity and debt. We maintain an appropriate mix of the two and manage financial risks prudently, committing to a strong overall investment grade credit rating.

Strategic and responsible leadership Expert colleagues

Our strategy articulates our priorities clearly and positions our business to support growth and long-term economic benefits, and a cleaner future, in the places we operate. We have well-established governance structures and controls in place to manage risk.

We are immensely proud of our people. Together we have spent decades installing and managing critical networks and systems, forging relationships, and building a culture of ambitious, diligent and passionate service.

Strong partner relationships

Customers

With our customers, including the electricity generators and gas suppliers who own the energy that flows through our networks.

Contractors

With our contractors who have complementary skills, experience and resources to help us get the job done.

Governments and communities

With national and regional governments and local communities who support us to deliver infrastructure that meets their needs.

Regulators and agencies With the regulators and agencies who agree the prices

we can charge and the amounts we can invest, as well as the health, safety and environment standards we must meet.

Strategic Report Corporate Governance Financial Statements Additional Information 9

The role we play in energy systems

Sources of power

‌Generation

In the US, we own and operate fossil fuel electricity generation facilities on Long Island. We also operate modern solar and battery storage projects with NextEra Energy Resources on Long Island. We facilitate the connection of energy generation assets to our transmission systems.

Integrating clean energy sources Renewables and zero carbon sources play a critical and fast-growing role in our energy systems. Facilitating connections to a wide range of clean energy sources is a fundamental part of our work. We earn a regulated return on the assets we build when extending our network to connect new energy sources.

Networks and infrastructure

Electricity interconnection Interconnectors are high-voltage cables used to connect the electricity systems of neighbouring countries to allow the trading of excess power and balance supply and demand to maintain security of

supply. We operate six interconnectors linking the UK to France, Belgium, Norway, the Netherlands and Denmark. We sell capacity on our interconnectors to facilitate cross-border flow.

Transmission

Our transmission networks transport energy over long distances, safely and efficiently from where it is produced to distribution networks. We charge generators and distributors for putting energy into and out of our networks, based on prices set

by regulators.

Delivering for customers

Distribution and supply

Our distribution networks take high-voltage electricity and high-pressure gas from the transmission networks, and deliver it at lower voltages and reduced pressures to homes and businesses, such that it can be used by consumers. In the UK and US, we deliver electricity. In the US, we also deliver gas and act as a supplier. Through our UK electricity distribution service operator, and in the US, we ensure that supply and demand are balanced. We earn revenue from transporting and distributing energy to businesses and homes.

10 National Grid plc Annual Report and Accounts 2024/25

Our business model continued

Delivering value

for our stakeholders

Customers page 48

Creation of jobs, skills and employability pathways, alongside

charitable community work and the long-term benefits of clean energy.

The value we create

31,645 60,511

Employees Volunteering hours

2023/24: 31,425

2023/24: 77,918

page 48

Communities

2023/24: 52%

2023/24: 0.08

An inclusive and safe environment where colleagues

can develop their skills and careers to reach their full potential.

The value we create

0.10 39%

Safety LTIFR per 100,000 hrs Jobs filled internally

page 51

Colleagues

2023/24: 72.1p (rebased) 2023/24: 10.5% (restated)

Supply chain and delivery partners

page 24

The value we create

73.3p

Underlying EPS

A low-risk and dependable investment proposition, focused on

generating shareholder value through dividends and asset growth.

Investors page 79

9.0%

Group ROE

Trusted relationships with shared goals to deliver energy

policies, growth and environmental commitments.

The value we create

3,016 MW

Renewable capacity connected in year

2023/24: 3,030 MW

£7,667m

Green capital investment

2023/24: £5,992m

page 256

Political and regulatory

Indicates an alternative performance measure Deloitte assured data PwC assured data

Our business environment

‌Our business environment is shaped by governments' drive to deliver economic growth amid a major shift in how we produce and consume energy. Against a backdrop of political and technological change, we are delivering the energy infrastructure of the future, enabling the energy transition and economic growth in our communities.

Growth in renewable and low carbon energy continues to be a

major driver of growth for our portfolio. Smarter and larger networks are needed to connect these new sources of generation and storage, at new locations, to customers.

92%

Renewable percentage of added global energy capacity in 2024

Energy transition

Impact on our industry

12 National Grid plc Annual Report and Accounts 2024/25

Our business environment continued

Governments are focused on driving economic growth and

development in our jurisdictions. Some of our customers continue to struggle with the cost of living.

#1

Voters consistently view the economy as a top issue in our jurisdictions

Affordability and economic development

Impact on our industry

Impact on our industry

14 National Grid plc Annual Report and Accounts 2024/25

Our strategy

‌We are guided by

our five strategic priorities

Enable the energy

transition for all

Build the networks of the future now

Deliver for customers

At National Grid, we are at the heart of a structural shift in how energy is produced and used. This will mean moving from centralised, fossil-fuel based systems to a more decentralised grid with higher renewable generation and storage. The areas we serve are at different points in this transition. Our goal is to build the networks needed in our jurisdictions, working with governments, regulators and communities to ensure the conditions for success are in place.

Our ambition is to deliver a once-in-a-generation increase in capacity on our networks. We continue to invest in the safety and reliability of our electric and (in the US only) gas networks. This will ensure we can deliver for our customers while we prepare for growing demand and electric load growth, and cleaner generation technologies.

To achieve this, we are growing our supply chain, capital delivery and network operations capabilities to deliver an unprecedented volume of capital investment. But our goal is not as simple as building more infrastructure. We are deploying better, more efficient technology to maximise the value of our existing and new assets, ensuring customers benefit from innovation on our networks and we maintain the affordability of our networks.

In today's digital world, the benchmark for excellent customer experience is not necessarily within our sector. Customers are used to streamlined, digital service in almost all their daily activities, from online shopping to booking appointments. They expect rapid resolution of any problems. We know our customers expect the best possible experience from us, whether they are residential and commercial customers relying on our networks to transport energy to their homes and businesses, or industrial and generator customers seeking a connection to our grid. We are committed to meeting today's needs and anticipating tomorrow's.

Strategic Report Corporate Governance Financial Statements Additional Information 15

Operate safely and efficiently

Build tomorrow's workforce today

Nothing is more important than the safety of our colleagues and the people in our communities. We want every person who works for National Grid to go home safely to their families each day. By embedding behavioural safety principles at all levels -across all business units and within our supply chain - we are shaping a proactive safety culture where everyone has the confidence, skills and environment to work safely every day. We also know efficiency is central for us in playing our part to keep energy bills down.

Ultimately, our people deliver our strategy. From apprentices to senior leaders, we are focused on attracting and developing a workforce equipped with the skills of the future. This helps us deliver our strategic priorities, but also ensures we're creating high value employment opportunities and economic impact in the communities

we serve.

…which are underpinned by our values

Do the right thing

Succeeding with our strategy

‌We deployed our five updated strategic priorities across the organisation in 2024/25

Our principal risks and uncertainties on pages 36-41

Enable the energy transition for all

What this means

We have an important role in the energy transition across all sectors of the economy through our networks. We work with policymakers, regulators and the wider industry to shape policy and regulatory frameworks needed to reach shared energy objectives.

Build the networks of the future now

What this means

We will scale a once-in-a-generation increase in network capacity to connect to, and transport electricity across, our networks. We will modernise our electricity networks to improve capacity, visibility, security and reliability. We will ensure the safety and reliability of our gas networks.

Business environment links:

Deliver for customers

What this means

We aspire to provide excellent service to all our customers, ensuring they can connect to the network in a timely fashion, that their energy provision is reliable and that we are easy to do business with.

Operate safely and efficiently

What this means

To deliver our part in a changing energy system, we are transforming our internal processes, strengthening our customer focus and sharpening our commercial edge. We are investing in the capabilities we will need in future and our ability to operate safely remains our top priority.

Build tomorrow's workforce today

What this means

Our colleagues shape the delivery of outcomes

that exceed the expectations of all our stakeholders. By attracting high-quality talent and developing our people, we will ensure our colleagues are best placed to deliver our goals.

Business environment links:

Our key performance indicators (KPIs)

‌We use a range of metrics through which we measure Group performance. In 2024/25, these metrics were aligned to our five strategic priorities.

Link to remuneration

Remuneration of our Executive Directors, and our employees, is aligned to the successful delivery of our strategy. We use a number of our KPIs/ alternative performance measures as specific measures in determining the Annual Performance Plan (APP) and Long-Term Performance Plan (LTPP) outcomes for Executive Directors. These measures are either specifically accounted for in remuneration targets or considered as part of a review of wider business performance.

Read more in the Directors' Remuneration Report on

pages 121- 149.

Link to strategy

Deloitte assured data

We engaged Deloitte LLP in the current year and PricewaterhouseCoopers LLP (PwC) in the prior years to undertake a limited assurance engagement, using the International Standard on Assurance Engagements (ISAE) 3000 (Revised): 'Assurance Engagements Other Than Audits or Reviews of Historical Financial Information' and ISAE 3410: 'Assurance Engagements on Greenhouse Gas Statements' over a range of data points within our Responsible Business data tables. The metrics identified with the leaf symbol, featured on page 1, pages 20- 21and page 77are included in the scope of their work. Details of Deloitte's assurance opinion and National Grid's reporting methodology are set out in the Responsible Business section. Please refer to page 58.

Enable the energy transition for all

Operate safely and efficiently Indicates an alternative performance measure

Build the networks of the future now

Build tomorrow's workforce today

Deloitte assured data 2024/25

Deliver for our customers

PwC assured data 2023/24

Financial measures

KPI and performance Description Progress in 2024/25

Underlying EPS (p)*

This is a measure of the Group's profitability for the year attributable to equity shareholders

Underlying EPS grew by 2% year-on-year, driven by strong performance in New York,

73.3p

73.3p

2024/25

72.1p

2023/24

68.9p

2022/23

Link to strategy

of the Group. It excludes exceptional items, remeasurements, timing, impact of deferred tax in UK regulated businesses (NGET and NGED) and US major deferrable storms (net of in-year allowances and deductibles) if these exceed $100 million threshold in a year.

As part of our five-year financial framework, we aim to grow Underlying EPS by 6-8% CAGR over the period to March 2029**

New England and UK ET coupled with lower finance costs more than exceeding the increase in share count driven by the Rights Issue. This is partly offset by lower profit from our non-regulated business and lower contribution from our share in joint ventures.

KPI and performance Description Progress in 2024/25

Group capital investment (£m) This KPI measures our annual investment into

property, plant and equipment, including

Group capital investment has increased by 20% on 2023/24 driven by a step up in critical

£9,847m

£9,847m

£8,235m

£7,593m

2024/25

2023/24

2022/23

Link to strategy

capital prepayments, intangible assets

and equity contributions to joint ventures and associates. Investing in our assets helps to increase our future revenue allowances.

We expect to invest around £60 billion between April 2024 and March 2029

energy infrastructure investment across our regulated businesses, including higher connections spend and early Accelerated Strategic Transmission Investment (ASTI) investment in UK ET and increased spend on new transmission projects in New York.

* Prior year comparatives restated to reflect the impact of the bonus element of the Rights Issue.

** From a baseline of 2024/25 Underlying EPS.

Financial measures

KPI and performance Description Progress in 2024/25

Green capital investment (£m)

£7,667m

£7,667m

2024/25

£5,992m

2023/24

£5,557m

2022/23

Link to strategy

In calculating green capital investment we measure the proportion of our capital investment that supports environmentally sustainable practices and contributes to the energy transition. Green capital investment excludes capital prepayments and equity investments in joint ventures and associates.

We expect to invest around £51 billion in green capital investment between April 2024 and March 2029

In 2024/25, we delivered £7.7 billion of green capital investment aligned to the EU Taxonomy, a £1.7 billion increase on 2023/24. This consisted primarily of investment in key infrastructure projects to support the energy transition, driven by a 33% increase in electricity network investments and a 16% increase in leak-prone pipe replacements across our gas networks.

KPI and performance Description Progress in 2024/25

Group RoE (%)*

In calculating Group RoE, we measure our performance in generating value for

During 2024/25 we achieved Group RoE of 9.0% compared with the 10.5% achieved in

9.0%

9.0%

2024/25

10.5%

2023/24

13.4%

2022/23

Link to strategy

shareholders by dividing our regulated and non-regulated financial performance, after interest and tax, by our measure of equity investment in all our businesses, including our regulated businesses, NGV and other activities and joint ventures.

Our aim is to achieve around 10% Group RoE each year

the prior year. In 2024/25 the metric has been impacted by lower gearing (as a result of the Rights Issue) which, along with ongoing asset growth, has increased the metric denominator.

KPI and performance Description Progress in 2024/25

Asset growth (%)**

Maintaining efficient growth in our regulated and non-regulated assets ensures we are

Asset growth during the year was 9.0% compared with 9.7% in 2023/24 driven by

9.0%

9.0%

2024/25

9.7%

2023/24

11.4%

2022/23

Link to strategy

well positioned to provide consistently high levels of service to our customers and increases our future revenue allowances. This includes critical investment for a changing climate and increased demand.

Our aim is to achieve c.10% CAGR asset growth April 2024 to March 2029 (from a March 2024 baseline)

£9.8 billion of Group capital investment. Asset growth is lower than in 2023/24 predominantly due to negative growth in our non-regulated businesses and reduced indexation on UK RAV due to lower inflation. Regulated asset growth is 10.5% compared with 9.1% in 2023/24 driven by a step-up in investment in UK ET and NY.

* Prior year comparatives have been restated to reflect the change in our 'Group RoE' definition. Refer to page 294for the updated definition and reason for methodology change.

** Normalised for the sale of UK ESO in the year.

Our key performance indicators (KPIs) continued

‌Non-financial measures

KPI and performance Description Progress in 2024/25

GHG emissions We are delivering new infrastructure to

Scope 1 and 2 emissions for 2024/25 were

Scope 1 and 2 emissions (mtCO2e)

7.4

2024/25

2023/24

2022/23

enable the digital, electrified economies of

7.4

the future. Our biggest contribution to reducing greenhouse gas (GHG) emissions, both across society and in terms of our own emissions, is what we do to enable the transportation and

7.3

6.9

distribution of clean energy in the regions where we operate. We understand the importance of partnership and are actively engaging with governments, regulators,

7,422 ktCO2e, outside of the range set out in

our Climate Transition Plan, demonstrating the likely nonlinear trajectory of our emissions targets. This is a decrease of 4.4% against our 2018/19 baseline. The increase in emissions in 2024/25 is largely due to an exceptional year of increased combustion of oil and gas at National Grid Generation on Long Island, attributable to contractual obligations with the Long Island Power

and the energy industry to ensure the

Authority (LIPA). Our Scope 3 emissions

Scope 3 emissions (mtCO2e)

28.4

28.4

2024/25

27.4

2023/24

27.9

2022/23

Figures are in million tonnes of CO2equivalent.

Link to strategy

policy and regulatory frameworks required for future investments in decarbonising the energy sector, and reducing our emissions, are in place.

Ultimately, we are helping to tackle climate

change by enabling the energy transition

for all and targeting net zero for our own emissions by 2050.

(excluding sold electricity) for 2024/25 as per our SBTi target were 25,566 ktCO2e, representing a 5.8% increase against our 2018/19 baseline caused by our increased capital investment in constructing new energy infrastructure.

You can read more about our GHG emissions and environmental performance on pages

44- 47.

You can read more about the Task Force on Climate-related Financial Disclosures (TCFD) and our wider sustainability activities and performance on pages 59- 77.

KPI and performance Description Progress in 2024/25

Group lost time injury frequency rate (LTIFR)

(LTIs per 100,000 hours worked)

0.10

0.10

2024/25

0.08

2023/24

0.11

2022/23

Link to strategy

Every day we strive to do the right thing, find a better way, and make it happen. Safety is our highest priority for our employees and the public. One of our main safety indicators is LTIFR. This is the number of worker LTIs per 100,000 hours worked in a 12-month period (including fatalities) and includes our employee and contractor population.

Our aim is to achieve 0.1 or below LTIs per

100,000 hours worked per year

Safety is an important factor within decision making for our Executive Directors' remuneration, reflecting the expectation that safety is an integral part of how we work at National Grid.

This year. we achieved a LTIFR of 0.10, compared to 0.08 in 2023/24, primarily driven by an increase in reporting of incidents such as trips, falls and manual handling injuries.

This reflects our continued focus on encouraging good safety behaviours across the entire workforce.

You can read more about our LTIFR performance in the Responsible Business review on page 56.

KPI and performance Description Progress in 2024/25

Employee engagement index (%)

80%

80%

2024/25

81%

2023/24

81%

2022/23

Link to strategy

This is a measure of how engaged our employees feel, based on the percentage of favourable responses to questions repeated annually in our employee engagement survey.

Our aim is for our employee engagement metrics to remain at or above the high-performing norm (as benchmarked by our external survey provider)

We run an employee engagement survey, Grid:Voice, twice-yearly, to understand and act on colleague feedback. This allows us to build a culture that is purpose-led and results-driven, with a great colleague experience. As a result, we enjoy high engagement and strong advocacy, above external benchmarks.

This year, 79% of colleagues took part in the survey (last year: 78%) and our employee engagement index score was 80% favourable. The score has remained consistent to prior years, however, three points below the high performing companies norm in the current year.

‌Non-financial measures

Network reliability and interconnector availability Customer satisfaction

We aim to deliver reliability by planning our capital investments to meet challenging demand and supply patterns, designing and building robust networks, and having risk-based maintenance and replacement programmes, and detailed and tested incident response plans. We measure network reliability separately for each of our

business areas.

Link to strategy

In both the UK and US, we continued to maintain high levels of reliability on all our networks.

Viking Link achieved its first full year of operation, achieving excellent 91.7% availability across the year. IFA has seen decreased availability this year due to increased planned and short unplanned outages.

BritNed has also seen decreased availability due to an extended planned outage and an unplanned outage due to a cable fault.

We measure customer and stakeholder satisfaction, while also maintaining engagement with these groups and improving service levels.

We are committed to efficiently connecting millions of people to the energy they use. In UK ET, we follow the Quality of Connections Incentive, for which it was a challenging year due to the rapidly growing connections pipeline and its impact on connection dates. We are working closely with others across the industry to address the challenges caused by the current connections pipeline.

In UK ED, we investigate areas of good practice across our licence areas, developing actions to deliver year-on-year improvement toward our target.

In the US, both regions faced high inflation and a long, unseasonably cold winter, causing impacts on affordability and negatively affecting our customers' sense of value. Our teams are working on enhancing business processes, expanding our energy efficiency and outreach, as well as adopting the latest technologies and undergoing training to drive improvements.

You can read more about our customer satisfaction scores in the Responsible Business review on pages 48and 50.

* The current year data for the Customer Trust Advice survey includes both commercial and residential customers to provide a comprehensive view of our entire customer base. Previously, only residential customer data was included. Therefore, prior year data has been recalculated to incorporate commercial customers for a consistent comparison.

Our stakeholders

‌Effective stakeholder engagement is key to achieving our long-term strategy

Section 172(1) Statement

The Board recognises its responsibilities to the Group's stakeholders and to wider society. The Directors strive to understand and consider the interests and views of stakeholders and take these into account in their decision-making. The Board is responsible for setting and monitoring the Group's culture and values, and these values guide the Directors in their decision-making.

The Directors consider all stakeholders when making key decisions, but recognise that not every decision will result in the preferred outcome for each stakeholder. The Board therefore seeks to balance the diverse and sometimes conflicting priorities and interests of the Group's

stakeholders, ensuring that decisions support the long-term, sustainable success of the business and uphold a standard of business conduct aligned to our values and purpose.

Throughout the year, the Directors have acted in the way they considered, in good faith, was most likely to promote the long-term success of the Company for the benefit of its members as a whole, and have had regard to the matters set out in section 172 of the Companies Act 2006. Further information on how the Board has had regard to each of the matters is set out below.

Section 172 factor Disclosure Page

The likely consequence of any decision in the long term

Our strategic priorities

14

Our business model 8

The interests of the Company's employees

Our stakeholders

22

Responsible Business review 42

Board workforce engagement 106

the environment

Responsible Business review

42

TCFD 59

Maintaining a reputation for high standards of business conduct

Responsible Business review

42

Corporate Governance overview 97

The need to act fairly as between members of the Company

Our stakeholders

22

Responsible Business review 42

Board stakeholder engagement 23

Delivery of the Group's long-term strategy can only be achieved by working with our customers and stakeholders, so we ensure we engage effectively with the right people at all levels of our organisation.

How we engage

Our stakeholder population continues to grow and diversify, and engagement with them is an integral part of our day-to-day business. Our approach remains to engage effectively and in a timely manner on the topics and decisions which matter most to our stakeholders, with engagement being led by the most appropriate colleagues. This involves everyone from our Board Directors, who regularly engage with key stakeholders, to working-level engagements supporting our day-to-day work, and all roles in between. We use the outputs of this engagement to inform the decisions we take to shape and deliver our strategy, with reporting mechanisms in place to enable a flow of information from our stakeholders to the Board and its Committees, and to help us act on what we hear.

Strategic Report

Corporate Governance Financial Statements Additional Information 23

Outcomes

Our engagement

Interests

‌Our customer base is broad, from those we have served for decades, to an increasing number of new customers. Their interests are wide-ranging but all expect efficient and reliable service, and transparency and fairness in how we work with them. We endeavour to understand their needs and challenges, and how our activities can impact their lives and businesses.

Investors are interested in our financial and operational performance, which act as key indicators of our ability to provide attractive returns and credit worthiness. There is also increased interest in our Responsible Business commitments and reporting to provide assurance that investments are sustainable, ethical and responsible.

Colleague interests are wide-ranging. They have an interest in Company performance and what this means for them individually, but also want to understand, and play a part, in shaping our role in the industry and the delivery of our strategic objectives.

In addition to day-to-day commercial interests, our supply chain and partners are interested in greater forward visibility and contractual commitments over a longer horizon to help them develop skills, build capacity and support innovation to meet

our needs.

Our communities need us to deliver energy securely, reliably and affordably, while minimising the impact our operations have on them and supporting those who need it most.

• We engage with community stakeholders and members of the public to understand their views and what they expect from us.

• We engage extensively with impacted communities as part of our major projects planning consultations, and we use their feedback to inform the proposals we submit for development consent.

• During the year, Board members visited operational sites and received management updates on community matters, including our strategic infrastructure projects and the RIIO-T3 business plan submission.

• Further details of how we engage with our communities can be found in 'Our customers and communities' on pages 48-50.

• Our outreach programmes continue to play an important role in supporting economic growth and the upskilling of communities, especially in the most socio-economically disadvantaged areas.

• In the US, our engagement has helped secure a requirement for a comprehensive needs assessment for electric vehicle (EV) charging along highway corridors, which helps enable investment to meet the demands for the communities we serve.

• In the UK, consultation with communities and residents living near our proposed new infrastructure projects is critical in helping shape our proposals and continues to be a key enabler for progression of new infrastructure projects.

  Outcomes

  Our engagement

  Interests

  Political and regulatory

  We engage with regulators, governments and other key political stakeholders tosupport the regulatory and policy frameworks requiredto deliver current and future energy needs. We work closely with our regulators on rate cases in the US and price controls in the UK.

The interests of our regulators and political stakeholders are based around a common theme -whether UK or US, state or federal - to protect the interests of customers and to deliver a secure, affordable and clean energy future.

The Board met with NESO and NYISO in November 2024 and received updates across the year on political and regulatory matters. Engagement included:

Our Business Units

‌UK

‌UK Electricity Transmission

Highlights

National Grid Electricity Transmission is the backbone of the UK energy system, supporting the growth of British business and acting as a critical enabler in meeting the country's Clean Power 2030 aspirations. In 2024/25 we continued to deliver safely for our customers and stakeholders with strong operational and financial performance. We have delivered more network capacity, connected more renewable energy, innovated and improved on our excellent financial performance compared to the previous year. Our Strategic Infrastructure unit, set up in 2023 to focus on the ASTI projects, is now well established to deliver those major projects. Our Great Grid Upgrade is underway.

Enable the energy transition for all

In December, we submitted our five-year business plan to Ofgem. This plan is the largest overhaul of the UK electricity grid in generations and will significantly reduce the UK's reliance on fossil fuels. The UK ET plan sets out investment of up to £35 billion between 2026 and 2031, around two and a half times UK ET's investment over the previous period (RIIO-T2). This investment will transform our network, nearly doubling the amount of power we can transfer across the country, providing twice as many customer connections as in the last five years and avoiding c.£12 billion of constraint costs, where there is less capacity on the network than unconstrained market positions would seek to utilise.

Build the networks of the future now

We have commenced construction of six ASTI projects, including Eastern Green Link 1 and 2 comprising 700km of high voltage direct current (HVDC) subsea cables straddling the English and Scottish borders, which has an

estimated investment of over £4 billion. We have secured primary delivery partners for eight of the remaining 11 ASTI projects with the remaining three projects in the final stages of procurement. Construction will commence once public consultations have completed and consents granted. We are working to deliver a number of other major infrastructure projects -we are re-wiring the capital in the London Power Tunnels project to improve network resilience, connecting the Hinkley Point C nuclear power station to help make net zero a reality, and delivering visual improvement projects in areas of natural beauty such as Snowdonia. We have taken a site strategy approach to consider multiple drivers for investments, including customer, infrastructure upgrade, asset failure risk and SF6(sulphur hexafluoride) emissions to identify substations to be rebuilt or decommissioned in RIIO-T3.

Our supply chain task force is collaborating closely across the industry and transforming how we think about procurement. This is in the context of competition for resource creating global supply chain constraints, with many countries upgrading their grids to connect renewable energy. While there is some inflationary risk around the evolving US Government position on tariffs, the impact of the US tariffs is not expected to be material relative to our spend. Over the last 12 months, we have launched three major initiatives to improve how we work in partnership with our supply chain - the Great Grid Upgrade, HVDC partnerships and a regional delivery model.

We remain committed to reducing our SF6emissions by 50% by 2030. To achieve this, we have collaborated closely with suppliers and universities, successfully trialling innovative leak repair technology, enabling us to avoid outages and keep electricity flowing while we work. Increased availability of SF6free technology will be critical to reducing future emissions and meeting this target.

Deliver for customers

This year we have continued works to connect the world's largest offshore wind farm,

Dogger Bank, connected the UK's largest transmission-connected battery energy storage unit (at the time of connection), connected the Greenlink interconnector between the UK and Ireland, and completed our first grid park at Sundon substation in Bedfordshire. Grid parks are a new and innovative way to connect renewable energy to the network, requiring fewer system outages and less commissioning resource, enabling more renewable energy to connect to the electricity grid more quickly at a lower cost.

We have collaborated closely with stakeholders across the industry to establish widespread agreement on the principles of the reforms needed to reduce connection timescales. The reforms are set to go live in spring 2025 to address a connections pipeline (in excess of 420 GW) that is more than three times the most ambitious net zero scenario published by the National Energy System Operator (NESO) and rapidly growing demand for data centre connections. Demand for data centre connections now totals 13.5 MW, the equivalent of connecting four Hinkley Point Cs to our network. Our T3 proposals will allow us to meet the increase in demand head on by ensuring that there is flexibility to respond to evolving customer requirements.

In May 2025, the NESO published its interim report investigating the outage following the fire at our North Hyde electrical substation in March 2025. The report establishes the timeline and sequence of events, and outlines further steps required ahead of the NESO delivering their final report, expected in June 2025. These investigations provide an opportunity to stand back and look together at how we can increase collaboration to ensure the resilience of important national infrastructure.

Read more about our business units on

pages 256 - 261

Our Business Units continued

Operate safely and efficiently

Our Lost Time Injury Frequency Rate (LTIFR) was 0.07 for our contractors and 0.07 for employees against the world-class safety standard of 0.10. This is an improvement in the safety performance of our contractors and follows a concerted effort on contractor safety, including embedding minimum contractor training standards in contracts.

Over the course of 2024/25 we delivered £32 million of totex synergies from integration with Electricity Distribution and over £14 million of enduring opex savings.

Build tomorrow's workforce today

Our RIIO-T3 plans are a step-change in how we invest in our people and plan our workforce. To deliver our commitments, we will expand our workforce, retain our experienced colleagues and upskill our people with the skills needed for the energy sector of tomorrow. We will continue to build a high-performance culture that has safety at its core. We have already embarked on this journey, expanding our workforce by over 600 employees to end the year close to 4,000 employees.

Looking ahead

The decisions we make in the next five years will shape the energy system, our economy and our society for generations to come. By the end of RIIO-T3, we will have nearly doubled the power that can flow across the country, reorienting the UK's once coal and gas reliant legacy system into one based on renewable energy and delivering the energy infrastructure needed for a digital economy. 2025/26 and RIIO-T3 will see Electricity Transmission power the country through change, supporting economic growth and decarbonisation as we deliver the grid of tomorrow, today.

UK Electricity Distribution

Highlights

UKED plays a vital role as the region's engine for growth. Every day we support 20 million customers across 8 million homes and businesses, delivering reliable electricity and connecting people to the electricity they need to power their lives.

Over the last year, UK ED has recorded strong operational and financial performance as we expanded our network, connected new demand and generation customers, and provided a safe and reliable service across four licence areas. We continue to provide an excellent service for our customers, with an average satisfaction score of around 9/10.

With a change of government and an ever-increasing focus on the future role of networks, we are shaping policy that impacts our sector and our region. The results of our extensive engagement effort can be seen in the publication of the National Infrastructure Commission's report into electricity networks, and in our early engagement on the ED3 regulatory framework.

We are hard at work building the electricity network of tomorrow, today.

Enable the energy transition for all

Throughout 2024/25, we have continued to focus on customer affordability and are proud of the support provided to our most vulnerable customers. Our first Customer Vulnerability Report in 2024/25 sets out how we helped 21,000 customers to save a total of £22 million through our fuel poverty programmes, as well as how we have continued to grow our Priority Services Register. We have also delivered a step change in our external engagement, shaping national and regional policy and ensuring we are supporting stakeholders with their growth and net zero agendas.

Over 4,500 stakeholder interactions took place through the year, making sure National Grid's voice is heard on the issues that matter, such as the future development of electricity networks, the ongoing development of Regional Energy System Planners, Local Area Energy Plans, and Connections Reform.

During the year, we awarded nearly £1 million to 247 grassroots organisations through our Community Matters Fund and our new colleague volunteering programme enabled

our people to volunteer over 10,000 hours to support local causes. We won the Corporate Community Local Involvement Award for impactful partnerships at the Charity Times Awards. Through our Solar for Schools initiative, we installed solar panels on five schools, and we launched new safety education resources for 4,953 schools, educating over 85,000 children on electrical safety.

Build the networks of the future now

In 2024/25, we powered growth across the Midlands, South West and South Wales, connecting new homes and businesses, over 40,000 electric vehicle charge points, 40,000 domestic solar PV installations and 16,000 heat pumps. In addition, we connected 595 MW of clean, renewable electricity to the grid, and through our Major Connections Strategy accelerated timelines for 2.9 GW of distributed energy resources by an average of 5.8 years in support of local net zero ambitions. This included the award-winning Horsey Levels solar farm in Somerset.

Read more about our business units on

pages 256 - 261

Our new Connections team has been a leading voice in connections reform, forming strategic partnerships with customers, including Octopus Energy and RWE. We held our first ever 'Connections Hackathon' event (in partnership with Octopus Energy), to facilitate collaboration in the development of solutions to enhance the overall connections process. We championed the phrase 'first ready, first needed, first connected' which has been adopted by NESO and now used widely in industry materials.

Our new ClearView products, ClearView Connect and ClearView Charge, are designed to increase transparency of data and information for customers ahead of the connection pre-application stage.

During the year, we launched our DSO strategy and continued to drive participation in energy flexibility programmes to better utilise network capacity and make room for growth. Our independent DSO Panel, comprising industry experts representing a broad range of stakeholder views, is adding strategic value by scrutinising DSO outputs. We have seen a strong performance in DSO incentives.

Deliver for customers

In the period we scored an impressive 8.98 out of 10 for Combined Broad Measure Customer Satisfaction and maintained high network reliability of 99.98294%.

Our network successfully navigated a difficult storm period. This included responding to Storm Darragh, the largest storm faced by the region in decades, with 96 mph winds and two red weather warnings. We recorded over 4,000 incidents during Darragh, with around

750,000 customers impacted, three times more than during Storm Arwen in 2021. Responding to the storm required a full scale response from the whole business and, through prompt deployment of colleagues and contractors and a fleet of five helicopters, we were able to restore power to 95% of customers within 48 hours. We also took proactive measures to keep customers informed through 22 broadcast media interviews, with additional interviews carried out in Welsh for Welsh-speaking customers.

We are also proud to have provided support to other DNOs in Ireland, Northern Ireland and Scotland in the form of field crews and helicopters during Storm Éowyn.

We were successful in securing funding through the Storm Arwen Reopener, which will further enhance network resilience through undergrounding high voltage overhead lines in wooded areas and introducing pre-fix technology.

Operate safely and efficiently

We are committed to ensuring the safety of every colleague. In 2024/25 we designed and delivered a company-wide behavioural safety training programme and have trained over 6,000 colleagues to date. Our Lost Time Injury Frequency Rate increased to 0.18 against the world-class safety target of less than 0.10, but the severity of recorded incidents has fallen.

We have exceeded our 2024/25 synergy target across National Grid Group, delivering

£88 million of cumulative benefit since acquisition, with high confidence to exceed the £100 million target by the end of 2025/26.

Build tomorrow's workforce today

We continue to invest in our workforce, hiring over 670 people in 2024/25 boosting our workforce to over 7,000 people working to ensure a safe, reliable, and growing regional network. It's not just our direct workforce, but our work also supports thousands more jobs throughout the supply chain.

We have continued to enhance our workforce capability by focusing on developing effective leadership through targeted development interventions and implementing a strategic workforce plan that provides a clear and forward-looking view of our future needs. We have also continued to hire a significant number of apprentices and promote social inclusion through our entry level Craft Attendant role, which is reducing barriers to talent entering our sector.

Looking ahead

In January 2025, we submitted our ED3 Framework Consultation Open Letter, setting out our thoughts on the approach to the next regulatory price control. The response emphasises the need for a transformative approach to electricity distribution networks to meet the UK's net zero targets by 2050. We also fed into the National Infrastructure Commission study helping to shape the future of distribution networks.

We will continue with engagement to influence and shape Ofgem's Sector Specific Methodology Consultation for RIIO-3 alongside the Energy Networks Association which is expected in Q3 2025.

Read more about our business units on

pages 256 - 261

Our Business Units continued

US

New England

Highlights

New England is focusing on business fundamentals, prioritising key initiatives that drive results and executing consistently to deliver our five strategic priorities. We connect our customers to the energy they need, while delivering strong operational and financial performance. We invested over $2 billion in our networks in 2024/25 while maintaining our focus on safety. With a new Rate Case Order for the Massachusetts electric business (MECO) and an approved Electric Sector Modernization Plan (ESMP), we are well positioned to deliver the infrastructure required to help meet energy demand, improve the customer experience and enable economic growth in our region.

Enable the energy transition for all

Our ESMP, or Future Grid Plan, was approved as a strategic roadmap by the Massachusetts Department of Public Utilities (MADPU). The five-year plan, designed to help Massachusetts meet its clean energy goals, outlines c.$2 billion in anticipatory investments in the NE electrical network which are foundational to meeting future energy demand, projected to more than double by 2050.

We received the MECO rate case order to fund the investments needed to maintain and improve reliability to support increased load growth on the distribution network with timely cost recovery. The approval of the capital recovery mechanism will enable us to invest at the pace required to meet customer needs and is a shift toward forward-looking ratemaking by the regulator. The core rate case can fund increasing capital requirements that are incremental to the ESMP. The order also favourably addresses the affordability and equity needs of our customers through multi-tiered low-income discount rates and provides performance incentive mechanisms aligned with increasing distributed energy resource

interconnections and enrolment in low-income assistance programmes.

This year we concluded a five-year project across our southeastern Massachusetts and Rhode Island transmission network to improve asset conditions and reliability, the largest ever project completed by our internal Transmission Line Services team. This extended the life of 345 kv circuits across four transmission lines, replaced over 750 poles and towers, and added over 100 miles of optical ground wire.

In addition, we connected over 197 MW of distributed energy resources, reduced lead times for those connections, and enabled the installation of 19.2 MW of EV charging infrastructure.

Build the networks of the future now

To more efficiently deliver our electric capital project portfolio, we built new capability, transformed how we secure long-term resources, and developed demand forecasts for key materials in categories with the highest market risk and criticality to 2030.

The implementation of our Future Grid Plan will be supported by a streamlined siting and permitting process codified in comprehensive climate legislation signed into law in November 2024.

We continued to expand our fault location isolation and service restoration (FLISR) capability that enables self-healing networks and improved reliability. In 2024/25 NE had

c.70 successful FLISR operations which restored power to 86,000 customers within a minute and avoided 14 million minutes of customer outages. Currently, 24% of our customers are covered by a FLISR scheme and we continue to deploy it across the state.

In our gas business we replaced 134 miles (216 kilometres) of older leak-prone metal pipe

to improve network safety and reduce methane emissions. We also continued to scale the use of low-dig technology to seal over 800 joints. As part of the DPU's requirement to evaluate non-pipeline alternatives, we are now progressing geothermal pilot activities in Boston and integrated energy planning to learn more about the practical realities of transitioning customers from gas to electric.

Deliver for customers

Significant steps were taken to improve the customer experience and deepen customer-centricity across all of our operations by focusing on foundational processes and evolving the structure and systems required for the future. We established an Account Management Team to better serve and connect our largest customers and continued to enhance our digital platforms to make it easier for customers to do business with us. We also successfully completed a billing system conversion, putting all six million of our US customers onto one platform. While the migration was successful, there were some issues leading to bill delays for some gas customers that arose over the winter, and which were subject to remediation following an order from the DPU.

Our Advanced Metering Infrastructure (AMI) programme is underway, installing the first 17,000 smart meters this year towards our over one million meter goal. AMI infrastructure will provide real-time energy insights to customers and provide opportunities for energy efficiency.

We have managed several storms, continuing to be recognised for exemplary performance in our service territory and in support of peers in the aftermaths of hurricanes Helene and Milton, including emergency response awards from the Edison Electric Institute.

Read more about our business units on

pages 256 - 261