Introduction

The Office for Statistics Regulation (OSR) is the independent regulatory arm of the UK Statistics Authority (referred to as the Authority). In this capacity, OSR is responsible for looking into concerns raised with the Authority regarding the production and use of official statistics. The investigations we undertake are called casework.

Our annual review of casework is aimed at anyone interested in the work of OSR and or how official statistics are used and communicated in the public domain. It draws together findings from our casework in the year from 1 April 2025 to 31 March 2026 (referred to as 2025/26).

The report focuses on the volume and type of issues raised with us across the 167 pieces of casework we investigated during 2025/26, and draws out several key themes and areas for reflection. One of these is our role and work during elections: although the main part of this report covers 2025/26, we have included a section that specifically covers work we completed during the 2026 election period, which began in March 2026 and ended on 7 May 2026.

This report is supported by Annex A, “Casework management information”, which provides information on the number of cases we received and the time it took to complete our investigations.

This report illustrates how our casework function continues to enable OSR to help ensure that statistics serve the public good as public assets that provide insights to, and shape actions by, a wide range of users in society.

What is casework?

Our process

Casework is generated when someone raises a concern with us, or when we identify a concern ourselves, regarding the production or use of statistics.

Our Interventions Policy sets out how OSR decides when it will or will not intervene in cases where there are specific concerns about statistics, especially their use in public debate. To find out more about our casework process, how to raise a concern and frequently asked questions, visit the casework pages on the OSR website.

When investigating an issue raised with us, we first identify whether the concern is within our remit. We often engage with the individual, organisation or data producer to which the concern relates. Some casework-related correspondence will be published on our website (or the Authority website when a letter is sent by the Chair of the Authority). Others will be private, and so will only be logged in our issues log, which records every issue that we consider. Our frequently asked questions page provides more details on our decision-making process for casework.

Our remit

Our statutory remit covers official statistics across the UK – statistics produced by Crown bodies (such as UK government departments) or bodies specified in statutory orders, as defined in the Statistics and Registration Service Act 2007. Official statistics must comply with the Code of Practice for Statistics.

But for casework, we take a broad view on what falls within our scope. We will consider issues relating to data and analysis published by UK governments whether they are formally defined as official statistics or not. This is because we recognise that public trust in the use of data extends beyond official statistics, and the distinction between official statistics and other data may not always be clear. We will intervene on an advisory basis where we judge that our intervention can support public trust in the use of non-official statistics in public debate, particularly in high-profile cases.

We consider the use of statistics and data by organisations who produce official statistics as well as members of governments across the UK. We also expect parliamentarians outside of government in every UK nation to adhere to the same standards as ministers when quoting statistics in public debate.

We will not generally comment on the use of statistics by the media – there are separate regulators of the press, broadcasting, advertising and political finance. We refer complainants to these regulators where relevant. However, where the media are quoting comments that use statistics, we may investigate and contact the person who was quoted if they are a statistics producer or member of government.

If you have a concern that you believe falls under our remit, please do raise a concern here.

Our regulatory role

In accordance with the statutory requirements set out by the Statistics and Registration Service Act 2007, we work to promote, monitor and safeguard the production and publication of official statistics. OSR is responsible for managing the Authority’s casework function. We undertake monitoring to identify and investigate issues raised with both OSR and the Authority.

Our core aim is to uphold the principles of the Code of Practice for Statistics (the Code), by ensuring that official statistics are produced and used in accordance with the Code principles of Trustworthiness, Quality and Value. The Code sets the standards that those producing official statistics should apply to deliver statistics that serve the public good.

But the Code is not just for official statistics. Everyone can apply or draw on the Code. It can help show what is needed to have confidence in data, analysis and statistics, whether as a user of information or as a producer of information.

The Code of Practice 3.0 was released in October 2025. It is still based on the core principles of Trustworthiness, Quality and Value (TQV), which are introduced in the section Understanding TQV. TQV is a useful framework for analysts and organisations both inside and outside of government.

The Code Principles unpack TQV and help anyone using data and producing statistics to work in a way that allows others to have confidence in their commitment to delivering the best possible outputs.

The Standards for Official Statistics set out the specific standards and practices related to each Code principle that producers of official statistics must follow to ensure that official statistics serve the public good and support public confidence.

Closely related are the standards that help ensure public bodies use statistics, data and wider analysis transparently and with integrity, clarity and accuracy. The Standards for the Public Use of Statistics, Data and Wider Analysis describe the standards and related practices that all public bodies should meet when communicating statistics, data and wider analysis in the public domain. These standards bring our work on intelligent transparency into the Code for the first time and have given us a stronger base on which to make casework interventions relating to the communication of numbers in the public domain.

Though it could be assumed that the most meaningful impact of casework would come from OSR’s public interventions, in many cases, behind-the-scenes conversations can be just as, if not more, impactful. Our impact is often greatest when we work together proactively, rather than reactively. For more on the hidden impact of casework, please see our blog on this topic.