Guidance

DSIT revisions and corrections policy for statistics

Updated 12 May 2026

1. Introduction 

This policy documents the revisions and corrections policy for statistics produced by the Department for Science, Innovation and Technology (DSIT), in compliance with the following practice set out in the Code of Practice for Statistics, Standards for Official Statistics: 

• Practice 3.9: Release revisions and corrections of errors transparently and as soon as possible in line with the organisation’s published policy, being clear about the nature and scale of change 

This policy sets out a process to ensure that all DSIT official statistics publications use a transparent and consistent approach for handling and communicating revisions and corrections of errors. This will be reviewed at least annually. 

2. Policy for published statistics 

This policy covers the production and publication of DSIT official statistics, as well as any statistics that are used externally.  

2.1 Planned revisions 

A planned revision is where statistics are initially published as provisional, which means that they are subject to change. At a later scheduled date, as announced on the upcoming statistical releases on GOV.UK, the statistics will be revised and reissued. Users will be given advanced notice of planned changes to methodologies and data sources that will impact released statistics. Additionally, advanced notice of material changes to the content of releases, such as the removal of tables or variables, and any change in the frequency of the release will also be provided.  

2.2 Unplanned revisions 

Unplanned revisions are those that do not fit into the pattern of revisions normally associated with the statistics in question. They can occur, for instance, at an unusual point in the revision cycle, or have an impact on the statistics that was not anticipated. They can be caused, for example, by errors, unforeseen changes in methodology, unexpected acquisition of new data, or by the effects of changes that may be made. Revisions can occur from both statistical and non-statistical reasons, to any administrative or management systems that contribute data to official statistics. The general rule is that when unplanned revisions are needed, they will take place as soon as practicable. 

2.3 Magnitude of revisions 

For both planned and unplanned revisions, it will be deemed by the Chief Statistician to be ‘substantial’ where it lies outside the range of revisions normally associated with the statistics in question and that tend, therefore, to have a more significant impact. Decisions on the content, format and timing of releases that incorporate substantial revisions will be made by the Chief Statistician.  

Where revisions are deemed to be ‘substantial’ a more detailed explanation of the change that has been agreed with the Chief Statistician is required and will outline the nature and scale of the change. Where a substantial unplanned revision becomes expected, but it cannot yet be made (e.g. due to data availability) this should be pre-announced in advance but without breaching pre-release access restrictions. 

For those revisions deemed by the Chief Statistician to be ‘minor’, these will be clearly marked identifying the statistics that have been affected with an explanation of the revision and where possible an assessment of the size of the revision. Where results are affected by methodological changes, a description of the change will be given. 

2.4 Removal of statistics 

In certain cases, a statistics publication will be removed from the department’s website or replaced by a statement giving a reason for the revision and a timetable for the replacement statistics. At the same time, a notice will be on the DSIT statistics release calendar (where relevant). 

3. Procedure for presenting revisions 

3.1 Provisional figures 

Statistics published as provisional should be clearly marked by a [p] in the relevant column heading, denoting that the figures presented in the column include provisional estimates. If only some of the estimates in the column are provisional, then include a footnote detailing which individual figures this applies to. Information should be provided on the reasons why the data is provisional and why a provisional release is necessary in addition to the finalised output. 

Once data initially published as provisional is revised, any [p] markers should be removed and replaced with an [r], with the footnote updated accordingly. Information on the reasons why the data has been revised should be provided. 

3.2 Revised figures 

Revised figures should be shown by the addition of a [r] in the relevant column heading, denoting that the figures presented in the column include revised figures. This should be accompanied by a footnote explaining which individual figures were revised and the reason for the revision. Revisions will only be marked in the first edition of each publication that the revised figures appear in. If the figures then appear again in future editions, they will not be marked as revised.  

The report should state when it was first published and when it was revised.  

In cases where revisions in cumulative spreadsheets, that is, where the latest data is added to a spreadsheet, which then replaces the previous edition on GOV.UK:  

• in the first edition after revision, revisions should be show by the addition of a [r] in the relevant column heading, denoting that the figures presented in the column include revised figures. This should be accompanied by a footnote explaining which individual figures were revised and the reason for the revision.  

• in subsequent editions, the [r] marker and original note should be removed from the spreadsheet and replaced by a note explaining what was revised, the reason for and scale of the revisions 

• the old publication will be removed but should be filed and available on request 

In cases where errors are found in time series that appear in more than one edition, the errors should be corrected in the most recent edition only. Older editions need not be corrected.  

Where changes are made to methodology or to definitions in a time series, revisions to the historical data in the time series should be considered to bring it in line with the new methodology or definitions. This may not be possible and depends on the data availability and the amount of work involved. The requirements of the users will be considered when making such decisions.  

If an error is identified but corrected figures are not yet available due to a need for further investigation, a note should be added to the statistics to explain the situation, making it clear the figures are subject to change. 

3.3 Learning and improvement 

Following the identification of an error: 

• steps should be taken to determine what corrective actions/training/communications are needed to prevent similar errors from occurring in the future. The emphasis is on learning from mistakes and improvement 

4. Policy for parliamentary questions  

If a parliamentary question (PQ) answer is found to contain an error, a correction needs to be made. The corrected answer will appear on the parliamentary website alongside the earlier response in a ‘correction to the official report’.