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Publication, Part of

GP Earnings and Expenses Estimates, 2020/21

Background Data Quality Statement

Data sources

GP populations for the earnings and expenses estimates are taken from several sources:

  • the workforce Minimum Data Set (wMDS) for GPs in England. The wMDS became the primary date source for GP data in England in September 2015; prior to this point, data were provided by the National Health Authority Information System (NHAIS). Completeness of this data set is improving from an initial figure of 88.1 per cent in 2015.
  • the National Health Authority Information System (NHAIS) for GP payments for GPs in Wales
  • from NHS National Services Scotland Information Services Division
  • the Northern Ireland Business Services Organisation

Earnings and expenses data come from Self Assessment tax returns held and analysed by HM Revenue and Customs statisticians.


The accuracy of the underlying data lies with the organisations providing the data. Missing or invalid data is removed from the datasets, and methods are continually being updated to improve data quality. This includes working with data providers to improve the completeness and coverage of the data.

As the report is based on a sample, the findings are weighted to present estimated results for the overall GP population. To do this, the population is stratified and appropriate weights are applied to minimise the effect of any bias in the composition of the sample.

Stratification methods have changed over the years, and detailed testing has always been carried out to assess the effect on the results. This testing indicates that changes in the weighting and stratification methodology do not result in a break in the time series.

Each country’s weighting factors are based on the strata (division of the population by age, gender, contract type, etc.), and the same set of weights are applied throughout, for all results except earnings distribution tables. Use of consistent weighting reduces complexity and potential risk of error. Standard errors are used where possible to assess the accuracy of the estimates. More detail is available in the Main Findings.

Because the results are based on samples with weighting applied, rather than the whole population, they are subject to sampling error and uncertainty. This is because using information from or about a sample of a population can never be as accurate as using the entire population.

Differences between groups and subgroups of GPs, or changes from one year to the next may not be statistically significant. Statistical significance is used in this report to illustrate the extent to which users can be confident that differences between compared results are not due to chance.

In addition, small GP populations for some subgroups mean that extreme values can have noticeable effects on the averages, and results in these instances may be subject to greater uncertainty.

Results shown in the GP Earnings and Expenses Estimates reports are rounded to the nearest £100 to show that the results are not exact. Similarly, population estimates are rounded to the nearest 50. Percentage changes and ratios are calculated using unrounded figures.

Figures are estimates and summarise how GP earnings and expenses have changed over time. However, it is important to note that they include both NHS and private work, and both full-time and part-time GPs are included in the sample.

Report population figures stated in the report are estimated and should not be regarded as the definitive GP populations; they will not be the same as those population estimates published in other NHS Digital reports. This is due to some GPs being excluded from the population for GP Earnings and Expenses Estimates for reasons listed in the methodology that accompanies the report.

All results received from HMRC are carefully checked before inclusion in the publication. In certain analyses, results are suppressed for groups with a small sample size, due to the sensitivity of earnings and expenses information. More detailed results are published in an accompanying Excel Time Series, an interactive web-based report and open data CSVs.

Any changes to the methodology or presentation of results are discussed by the Technical Steering Committee (TSC) prior to implementation. 


GP earnings and expenses estimates are primarily used as evidence to be presented to the Review Body for Doctors’ and Dentists’ Remuneration to make annual recommendations on remuneration for GPs.

This report has been agreed by the Technical Steering Committee (TSC), which is chaired by NHS Digital and has representatives from:

  • Department of Health and Social Care
  • NHS England and NHS Improvement
  • The Welsh Government
  • The Department of Health, Northern Ireland
  • Scottish Government
  • NHS National Services Scotland: Information Services Division
  • The British Medical Association
  • The Secretariat for the Review Body on Doctors’ and Dentists’ Remuneration
  • The NHS Business Services Authority Information Services
  • HMRC: Knowledge, Analysis and Intelligence Division

Coherence and comparability

Methodologies used in the analyses have changed over time. Any changes in methodology or presentation of results are discussed and agreed with the Technical Steering Committee (TSC).

Comparisons across domains such as NHS England (Region) within countries are appropriate and encouraged. If making comparisons across countries, it should be borne in mind that different contracts are in place for the provision of General Practice services which may have an effect upon the estimates.

The results are largely comparable over time, and comparisons are made in the report to the results from the previous year. When comparisons should be made with caution, explanatory footnotes are provided.  

The use of unrevised superannuation contribution estimates when calculating the income before tax in earlier years means that, in some cases, results for those years are not comparable with others. Where this is the case, a time series break is clearly displayed.

Further information can be found in the Methodology section.

Timeliness and punctuality

The estimates are based on the HMRC Self Assessment tax records of GPs and analysis can be undertaken only after the closing date of the Self Assessment period. Therefore, each report refers to the previous tax year which is the most recent year for which Self Assessment tax data are available. For example, the report released in 2022 relates to the 2020/21 financial year.

The report only contains data for GPs with an accounting year end (AYE) during the fourth quarter of the financial year (i.e. 1 January to 5 April). This period has been found to be representative of the entire financial year. The tax data covers income from all GP sources, including private GP work.

There have been no issues in relation to punctuality in the production of this report.


All reports are accessible via the NHS Digital website and include supporting csv, Excel Time Series file and a web-based interactive report.

Performance cost and respondent burden

The report is secondary use of the workforce data provided and therefore adds no burden on the NHS.

The HMRC data used within the analyses is also a secondary use of an existing administrative database (the Self Assessment tax database) and adds no additional burden on the industry.

Confidentiality, transparency and security

All publications are subject to a standard NHS Digital risk assessment prior to issue. Disclosure control is implemented where judged necessary.

In order to maintain taxpayer confidentiality, HMRC suppressed the results for any analyses that would produce results for subgroups with low sample numbers and performed secondary suppression where required to ensure suppressed results cannot be calculated.

Data is held on secure, encrypted servers and transferred on secure file transfer systems or secure email. Data Sharing, Data Processing and Service Level Agreements exist between all parties involved in production of the report to ensure appropriate security levels are maintained.

The data contained in this publication are Official Statistics and comply with the UK Statistics Authority’s Code of Practice for Statistics.

Last edited: 1 September 2022 9:19 am