Introduction

Who we are

The Office for National Statistics (ONS) is the executive office of the UK Statistics Authority (the Authority). Led by the National Statistician, Sir Ian Diamond, it is the UK’s national statistical institute and largest producer of accredited official statistics.

The ONS delivers independent, high quality and relevant statistics and analysis. Our statistics and analysis are crucial evidence for decision making by central and local government, the health service, businesses, charities and communities across the UK, as well as informing public debate.

The ONS responds to changing contexts and user demand for more flexible, tailored and granular data, including through transforming our approach to how we produce statistics across the economy, population and society. This includes advancing data linking across government to enable faster, evidence-based decisions, and gripping the opportunities and challenges of new technologies (such as artificial intelligence, including large language models) to shape and support thriving analytical and statistical systems for the future.

Our key services include:

• Measuring changes in the value and composition of the UK economy.
• Estimating the size, geographical distribution and characteristics of the population (including information from the census).
• Providing analysis on and indicators of other social and economic topics of national interest.

Our four priority outcomes are:

1. An enhanced reputation for delivering trusted, relevant, independent statistics and analysis.
2. Top quality published statistics on prices, GDP, the labour market and population (including births, deaths, and migration).
3. Support the Government’s missions and other users by maximising the use of our statistics and responding to evidence gaps where we are uniquely positioned to do so.
4. Greater linked data capabilities that result in faster, evidence-based decisions across government.

The National Statistician also leads the following cross-government networks:

• The Analysis Function – consists of around 17,000 people involved in the generation and dissemination of analysis across government and beyond. The function aims to improve the analytical capability of the Civil Service.
• The Government Statistical Service (GSS) – is spread across a range of government departments and public bodies, including components of the devolved administrations.

The ONS sits at the heart of the GSS and Analysis Function and works with the network to provide the statistical evidence base, professional advice and analysis required by decision-makers to ensure policy and operations are evidenced and deliver value for money.

The ONS’s outputs, in line with the rest of the GSS, are regulated by the Office for Statistics Regulation (OSR). The OSR sets the code of practice, ensures that statistics are produced and disseminated in the public good, and enhances public confidence in the trustworthiness, quality and value of statistics. Those that meet the highest standards are given Accredited Official Statistics status by the OSR – this applies to a range of the ONS’s key outputs.

Vision and mission

The mission of the UK statistical system is:

“High quality data and analysis to inform the UK, improve lives and build the future”

Evidence produced free from political and commercial influence is a cornerstone of democratic society. It allows for the better formulation and evaluation of public policy; it informs public understanding of the world and our place in it; it informs decision-makers to take choices, and lets others hold the powerful to account. The ONS is uniquely placed for its role in this through the following:

• A statutory remit enshrined in the Statistics and Registration Service Act to independently produce and safeguard national statistics, and support the design of policy and produce analysis for the public good.
• Guiding principles of trustworthiness, quality and value enshrined in the statutory Code of Practice for Statistics, overseen by the OSR.
• The ability to bring together all those involved in producing statistics that serve society by convening cross government analytical capability and research interests through the breadth and talent of the GSS, the Government Analysis Function and the broader scientific and research community in the public and private sectors.
• Access to data under the Digital Economy Act, which supports access to new sources of data, safely and securely.
• Expertise in linking data from different sources.
• The practical application of data ethics, through the National Statistician’s Data Ethics Committee and the exercise of impartiality, transparency and openness in to retain the trust of society.

Our structure

The United Kingdom Statistics Authority (the Authority) is our governing body. Sir Robert Chote is the Chair of the Authority Board. Professor Sir Ian Diamond is the ONS’s Chief Executive, Permanent Secretary and National Statistician.

The National Statistician’s team comprises five direct reports:

• Deputy National Statistician for Economic, Social and Environmental Statistics
• Deputy National Statistician for Data Capability
• Deputy National Statistician for Health, Population and Methods
• Chief Financial Officer
• Director for Operations and Chief People Officer

There are 17 Directors:

• Director of Economic Statistics, Production and Analysis
• Chief Economist and Director of Macroeconomic and Environment Statistics and Analysis
• Director of Economic Statistics Change
• Director of Public Policy Analysis
• Director of Data Science Campus
• Director of Health and International
• Director of Population Transformation
• Director of Population Statistics
• Director of Methodology and Quality
• Director of Integrated Data Programme (vacant)
• Chief Digital and Information Officer and Director of Digital Services
• Director of Data Growth and Operations
• Chief People Officer and Director for Operations and People and Business Services
• Director of Finance, Planning and Performance, and Chief Financial Officer
• Director of Communications and Digital Publishing
• Director of Social Surveys
• Director of Business Surveys

There are three other posts that report to the National Statistician on a functional basis because of the nature of the roles.

• Head of Internal Audit
• Chief Security Officer
• Data Protection Officer

April 2024 to March 2025 performance summary

The ONS has faced several challenges over 2024/25. These challenges include dealing with falling survey response rates while also transforming statistical production systems and meeting user needs for more timely, granular statistics including through the use of administrative data.

The ONS recognises the real challenges that remain with its Labour Force Survey (LFS) and are prioritising addressing these. The ONS, along with other national statistical institutes, has faced the challenge of falling response rates to household surveys with existing trends exacerbated during and after the pandemic period. At its lowest point in 2023 the LFS overall response rate stood at 12.7% and the associated achieved sample was 14,180 households containing 29,220 individuals. This shortfall in achieved response resulted in significant implications for the quality of statistics derived from the LFS, where we have seen elevated volatility and reduced precision in the resulting labour market statistics.  At the same time atypical movements in the UK population, particularly migration flows, have caused additional challenges for these statistics. This is important because labour market statistics are a significant source of evidence for decision-making that underpins financial and economic stability.

The scale of the quality issues with the LFS resulted in the temporary suspension of LFS derived Labour Market Statistics from October 2023 to January 2024. To address these issues the ONS introduced a survey recovery plan, which set out the significant steps required to restore the quality of LFS estimates. These measures have evolved over the subsequent period but can be broadly categorised into improvements to data collection and methodological enhancements. Alongside this, the ONS has focused on communicating to users how they should interpret and make use of LFS derived statistics in the period before they are fully recovered, including making use of our full suite of labour market indicators which includes surveys of businesses and HMRC data on the number of people on payrolls. Progress continues to be made in recovering the LFS with the achieved sample now significantly higher and the incorporation of updated population information into the estimates complete.

Work has also advanced on our strategic solution, the Transformed Labour Market Survey (TLFS). Its online-first design means we can approach many more people in different ways to produce the best possible picture of the labour market. However, as a new self-completion survey, it has taken time to fully develop to ensure we are achieving the quality necessary for users. In late 2024 we tested a shorter version of the questionnaire aimed at further improving data quality and plan to provide a further update on next steps in April 2025. Both the work to recover the LFS and to develop the TLFS has benefited from the introduction of a new Stakeholder Advisory Panel, chaired by Professor Jonathan Portes, assurance from academic experts and extensive engagement with key users.

In addition, the organisation has faced challenges with other core economic statistics: trade in goods, trade in services, producer prices and average earnings. These reflect both errors made by data suppliers, and in the methods applied by legacy statistical systems.

Against the backdrop of these challenges with the LFS, public sector financial constraints and the need to find efficiencies, difficult choices were necessary about where we placed our resources. To ensure we remained affordable while recovering performance on the LFS, the ONS delivered £12.1 million of efficiencies in 2024/25 including absorbing the impacts of inflation. By the end of the 2024/25, we estimate that the annual effect of cumulative efficiencies and savings generated across the Spending Review (SR) 21 period will be £39.2 million. This equates to 9.9% of forecast net expenditure estimated at £396 million for 2024/25.

Measures contributing to meeting this savings and efficiencies target included streamlining our outputs, automation of processes, revising our commercial approaches and reducing our corporate services costs. While this released some savings for reinvestment to maintain our highest priority outputs we had to scale back in additional areas, for example on planned improvements to the Crime Survey for England and Wales and by reducing climate, environment, economic and broader analytical capabilities. These decisions have been unpopular with some of our users and has meant that we have been unable provide previous levels of support to some Government departments’ policy areas.

We used continuous improvement principles to seek to manage quality and mitigate risk through the end-to-end production processes of our key economic statistics. We also worked with an external partner to develop an improved way to manage our statistical production processes, with tools and techniques that will be rolled out across the organisation. Alongside our existing programme of implementing reproducible analytical pipelines, this should result in increased quality and efficiency.

Addressing our IT and coding legacy systems also remains a sustained focus. We ensured that our systems continued to be supported, maintained and secure. We also ensured that the costs of continuing to fund legacy systems were affordable particularly where specialist skills for their management were scarce. Nonetheless, addressing legacy systems remains high on our agenda in 2025/26.

Against this testing backdrop, ONS has continued to work alongside and as an integral part of the GSS, and in collaboration with other key stakeholders, to deliver our statistical outputs and respond to analytical demand. This collaborative approach to delivery and continuous improvement of our statistics will continue to be an underpinning element to our plans in 2025/26.

Despite these challenges, there is much to celebrate in organisation’s performance over 2024/25. The following sub-sections present highlights from the year. More performance information can be found in the Authority’s 2024/25 Annual Report and Accounts, which will be published once it has been laid before Parliament.

Economic statistics

To enable urgent quality improvements to the social surveys feeding economic statistics, we received additional funding from HM Treasury in 2024/25. This was invested in increasing our interviewer numbers, implementation of changes to bolster retention, and increasing incentives for survey respondents. This has helped to improve performance on key surveys, but we need to do more to improve performance across our full survey portfolio – a theme which is covered in our plans for 2025/26. We are hopeful that our survey recovery strategy, including focused resources in this area, will help us continue to improve response rates in an increasing challenging environment. Despite advances in administrative data, surveys remain essential to production of economic statistics.

The Blue Book and Pink Book were successfully published in October 2024, with the latest data and a full rebasing to 2022 to ensure continued accurate measurement of the UK economy. Alongside this were the regular publications of the Quarterly National Accounts, Sector Accounts, Balance of Payments and related releases. We also published a range of economic statistics showing the UK’s relationship with the rest of the world, including UK Trade, Foreign Direct Investment and Mergers and Acquisitions, and have moved off some of our legacy systems. In addition to the annual and quarterly releases we also published monthly economic indicators and GDP estimates, with a weekly real time indicators release completing the picture of how various areas of the economy were performing.

We delivered a full redevelopment of Research and Development (R&D) statistics, including significant improvements to sample, methods, concepts, systems, and the use of administrative data. This resulted in fuller coverage of the level and type of UK R&D activity to inform the Government’s mission on economic growth.

Each month, the ONS and HM Treasury jointly produce vital public sector finance statistics on taxation and public spending and monitor the government’s performance against its fiscal targets. The ONS has produced analysis in line with the Chancellor’s new fiscal rules, including the investment rule based on Public Sector Net Financial Liabilities (introduced in 2016). Beyond monthly bulletins, they have made statistical improvements such as enhancing central government debt interest data and updating classifications of public sector bodies.

Each month, ONS produces vital statistics on consumer and business prices and the housing market. In 2024/25 we made substantial progress in moving our house price production system off a legacy system, addressed the recommendations of an OSR review into producer prices, and introduced new and innovative methods for deriving key deflators using administrative data and multilateral methods. We also began the regular quarterly publication of our new Household Costs Indices.

The Prices Transformation Project delivered a wide range of changes in 2024/25, which significantly reduced reliance on aged infrastructure and increased the resilience, sustainability and efficiency of consumer prices monthly production. The changes also allow for the easier implementation of new methods, a new classification structure that will allow the better use of administrative data, and new Northern Ireland rents data. The capability to use scanner data was delivered in March 2025, however, following extensive stakeholder engagement, it was decided to dual run alongside the existing methods for a year to allow further time for quality assurance and lay the foundations for going live in March 2026.

In addition, several core economic statistics were moved off legacy onto modern software and platforms during 2024/25. These include the House Prices Index, Foreign Direct Investment, and Productivity.

The Public Services Productivity Review was delivered successfully to target in March 2025. This once in a generation review improves the productivity measures of UK public services to aid government policy and decision making, delivering new methods, systems and a strategic roadmap for incorporating the improvements into the UK National Accounts as part of the ONS’s wider System of National Accounts 2025 implementation. The Review has also provided ground-breaking insights into how public sector workers spend their time, management practices in the public sector, and their views on the opportunities for, and barriers to, use of automation and Artificial Intelligence (AI).

Population and migration

In May 2024, we published a Reason for Migration output which included a net student migration estimate. This informed debate on whether international students stayed after completing their studies and if so, for how long. This has led to further user consultation in spring 2025 to identify what other net migration estimates users need.

Also in May, we published estimates of veteran suicides for 2021 for the first time. This was the result of a long running project with Office for Veteran Affairs (OVA) and Ministry of Defence (MoD) supporting the armed forces covenant of preventing veterans’ suicides.

In summer 2024, we published administrative based population and migration estimates, which were major milestones of the Future Population and Migration Statistics (FPMS) Transformation Programme. We invited the OSR to review the quality of the population estimates and their assessment noted “the work that ONS is doing to improve estimates of the population in England and Wales is at the forefront of harnessing technological advancements for statistics production”.

Other notable FPMS Programme milestones achieved include placing a developmental administrative based census in the Integrated Data Service enabling onward data linking and more granular insights and publishing an action plan against the OSR recommendation for administrative based population estimates to be accredited as official statistics by summer 2025. FPMS continues to deliver on its key milestone to finalise and issue the recommendation for the future of population and migration statistics, considering the interests of HM Government as key users, and wider feedback, such as from the UK Statistics Assembly.

In January 2025, we published 2022-based national population projections, which integrated transformed migration statistics and included a new interactive tool on our website. The tool allowed users to assess impact of different demographic changes and explore the impact of higher or lower assumptions on the projection.

Crime

The ONS Centre for Crime and Justice released, to time and quality expected, the strategically important quarterly Crime in England and Wales statistics series throughout 2024/25. With financial support from the Department for Education and the Home Office, we also further developed our work on measuring crime against children. We successfully piloted the Young People’s Safety Survey, and we are now ready to start piloting the Safety During Childhood Survey in our newly established collaboration with the National Society for the Prevention of Cruelty to Children (NSPCC), although this depends on securing additional external funding.

Working closely with partners across government and the private sector, we took an innovative approach to shaping how we measure Violence Against Women and Girls to support the Government’s Safer Street Mission. We also worked closely with the OSR so that the estimates of crime from the Crime Survey for England and Wales were successful in regaining ‘Accredited Official Statistics’ status.

Health

In April 2024, the ONS endorsed the refreshed Health and Social Care strategy which included pivoting pandemic investment into a sustainable model for population health measurement and analysis. Contributing to this strategic aim, we successfully repurposed the winter covid infection survey platform for use on an National Health Service (NHS) England funded survey, the Health Insight Survey (HIS), focussing on patient experiences at GP practices and other NHS services.

We linked data assets, including the Public Health Data Asset, to monitor health inequalities. Through funding from a range of partners, we have linked NHS datasets with census, social security benefits and HMRC data to understand the interplay between health and work. The analyses show the impact of a range of NHS interventions, including bariatric surgery, NHS talking therapies and endometriosis diagnosis, on people’s earnings and employment. These analyses have directly helped inform government spending in areas with high levels of economic inactivity.

Thanks to funding from Wellcome, we researched and published findings on the consistency and quality of ethnicity recording in NHS administrative data sources to support future research and policymaking. Consistent ethnicity coding within health datasets play a crucial role in understanding health disparities, identifying vulnerable populations, and tailoring healthcare services to meet diverse needs effectively.

We also improved our regular statistics on deaths and births through increased automation and methodological developments.

The Sudlow Review was launched, commissioned with Sir Chris Whitty, to look at the UK health data landscape. It set out a bold vision for overcoming the barriers and inefficiencies that currently delay the safe and secure use of health data to improve lives, making the case for the Integrated Data Service and the criticality of a linked data infrastructure is to drive positive outcomes for the public.

Responsive analysis

The ONS continued to respond to emerging and priority topics and changing contexts that the public and government face. We worked to provide analysis and develop the evidence base to support the Government’s missions, such as Economic Growth, Safer Streets and Barriers to Opportunity, as well as newly created task forces focused, for example, on child poverty.

Our Opinions and Lifestyle Survey (OPN) continued to provide timely insights on a range of priority policy requirements including the Barriers to Opportunity Mission, trust in elections, flood prevention scheme awareness, and attitudes towards artificial intelligence and big tech companies. Its sister survey, the Business Insights and Conditions Survey (BICS) continues to gather intelligence from a business perspective.

In May 2024, we published statistics on ship crossings through critical maritime passages. These statistics shed light on trade disruption meeting the needs of Department for Business and Trade (DBT), Department for Transport (DfT) and the Cabinet Office.

Through our Ukrainian Humanitarian Survey, we have responded and evolved to meet new policy needs winning both a Government Social Research award and Analysis in Government impact award in 2024. Our most recent release surveying Ukrainians in the UK was published in June 2024.

Subnational statistics

In 2024/25, we continued to produce hyper-granular economic statistics. For example, we embedded our innovative gross value added estimates at Lower-layer Super Output Area (LSOA) and equivalent geographies into regular Regional Accounts production in August 2024. A Lower layer Super Output Area (LSOA) is a unit of population in England and Wales 1,000 to 3,000 people (400 to 1,200 households).

In March 2024 we explored, in collaboration with HM Treasury, the educational attainment and geographical mobility of young people across England, using the Longitudinal Educational Outcomes datasets.

In July 2024, we investigated firm employment dynamics in local economies through the Longitudinal Business Database, focusing on job creation and destruction across International Territorial Level (ITL) 3 subregions between 2004 and 2022. More information on ITLs is available on the ONS website.

In October 2024, we provided analysis on how access to local amenities, varies, both within and between local areas in England and Wales.

In the same month, we used financial transaction data to understand domestic and international spending in tourism-related industries, moving one step closer to a faster indicator for the tourism sector contribution to the economy.

Integrated Data Service

The Integrated Data Service (IDS) is a functioning cross-government tool that allows full value to be extracted from deidentified, sensitive data collected across the public sector and beyond, permitting it to be safely linked and analysed to answer key questions for ministers, officials and researchers.

IDS successfully extended its Digital Economy Act (2017) accreditation for data provision and the service now contains a critical mass of valuable data (100+ datasets available), including systematic linkages between the most sensitive personal and business data (such as census records, tax records and health records). Agreements are in place to expand this further, including to benefits, justice and education data.

Analysis of this data is already supporting a host of innovative analytical projects feeding into the Government’s missions, covering four distinct areas critical to growth, health, crime, energy and opportunity.

Data, new tools and innovation

In March 2024, we launched Explore Local Statistics (ELS), a digital dissemination service to find out more about local areas across the UK. The service allows users to find, visualise, compare and download over seventy subnational indicators from across Government in one place, addressing a well-documented need for improved accessibility and dissemination of local data. ELS won the 2024 Royal Statistical Society Campion Award for Excellence in Official Statistics in recognition of its “real potential to empower local areas, providing them with the data they need to make the right decisions”. It also won the 2025 Analysis in Government Communication Award.

In April 2024, we published a Visa big data article on the flow of consumer card spending across the UK, containing unprecedented insights into the relationship between where people live and where they spend.

We also developed new methods for population and migration statistics, including using Advanced Passenger Information (API) to replace the International Passenger Survey for international migration estimates.

Our large, cloud based, digital infrastructure is now recognised across government for its security, efficient design and scalability. We implemented AI in the ONS, including the successful roll out of Microsoft Copilot, development of the first ONS AI policy and an associated governance framework. We were also a significant contributor to the “AI Playbook for UK Government” recently published by the Cabinet Office.

In addition to implementing a series of improvements to the stability of our website, we released previews to our new website platform that will better help users find, understand explore and act upon our data and statistics. We are also continuing our programme of legacy replacement to support the ongoing improvement of statistical quality and development of the new Statistical Business Register private beta.

International leadership

Over the course of 2024/25, ONS colleagues collaborated with delegations from national statistics offices of Australia, Jordan, the United Arab Emirates, South Korea, Kazakhstan, Namibia, Ghana, Rwanda and Japan. Discussions covered a range of topics of mutual interest, sharing of best practice, and bilateral programmes of cooperation.

In October 2024, on behalf of the UK Statistics Authority, Sir Ian Diamond signed an arrangement on statistical cooperation with Eurostat. This agreement will enhance collaboration between our offices, with an initial focus on the transfer of GDP data as well as other areas of economic statistics. The arrangement is a living document and there is a possibility of adding additional areas in future if agreed with Eurostat.

We continue to progress the Pandemic Preparedness Toolkit project and this year we began working with international partners in Nepal, Malawi and Argentina. The toolkit, funded through Wellcome, is being co-developed using the breadth of experiences across the partnership. It aims to unlock the potential of national statistics offices to add value to health surveillance systems during future infectious disease outbreaks.

Organisation

The ONS was awarded “highly commended” in the Best Equality, Diversity and Inclusion Initiative category at the Chartered Institute of Personnel and Development (CIPD) Wales Awards. Our submission highlighted the incredible work to develop and embed the inclusion, culture and wellbeing dashboard, our inclusive interactive experience, and ‘hold to account’ sessions all of which aim to further our strategic driver of ‘Inclusive’.

Performance against April 2024 to March 2025 key milestones