FOI reference: FOI-2026-3481
You asked
I am writing to make a request under the Freedom of Information Act 2000. I would be grateful if you could provide the following information relating to the ONS's own internal workforce, for each quarter from Q1 2000/01 (April--June 2000) to the most recent quarter for which data is held:
1. Headcount The total number of ONS staff in post (headcount basis, excluding temporary agency workers) as at the end of each quarter.
2. Joiners For staff who joined the ONS in each quarter, please provide:
a) The total number of joiners
b) A breakdown of joiners by grade band at point of hire. Please use whichever grade structure the ONS held for the relevant period (e.g. if grade classifications changed over time, please provide data using the structure in use at the time rather than mapping to a current framework).
3. Leavers For staff who left the ONS in each quarter, please provide:
a) The total number of leavers
b) A breakdown of leavers by individual grade at the time of leaving. Please use whichever grade structure the ONS held for the relevant period (e.g. if grade classifications changed over time, please provide data using the structure in use at the time rather than mapping to a current framework).
c) A breakdown of leavers by reason for leaving (e.g. resignation, retirement, redundancy, end of fixed-term contract, dismissal, or similar categories as held)
d) A breakdown of leavers by the following tenure bands, reflecting time served at ONS from joining date to leaving date:
- Less than 1 year
- 1 to less than 2 years
- 2 to less than 5 years
- 5 to less than 10 years
- 10 to less than 20 years
- 20 years or more
Where possible, please provide this tenure breakdown cross-tabulated with individual grade. If a cross-tabulation is not readily available, a standalone tenure band breakdown per quarter would be acceptable.
We said
Thank you for your request submitted under the Freedom of Information Act.
The information you have requested spans 26 years of information, which is currently held across multiple systems, including archived systems. This archived information is held in a format that is not easily interrogated. Therefore, for us to conduct a search to locate, extract, and collate all of the requested information, and in particular the detailed breakdown of leavers data requested, would take in excess of 24 working hours to action, exceeding the cost limit for FOI requests and engaging s.12 of the Freedom of Information Act 2000 (FOIA).
However, some of the data related to your request are publicly available, which we hope will be useful:
Quarterly headcount data:
We publish data from the Quarterly Public Sector Employment Survey on the ONS website dating back to 2011: Public sector employment - Office for National Statistics
Data for 31 March 2026 are due to be published on 18 June 2026.
Joiners and Leavers data:
Annual data, on departmental joiners and leavers, reflecting data for the year to 31 March, are published via Civil Service Statistics on the GOV.UK website, dating back to 2006: Civil service statistics.
Data for the year ending 31 March 2026 are due to be published at the end of July 2026.
If you wish to obtain a summary of leavers information, in aggregate form (not against the detailed breakdowns) to mitigate against inadvertent disclosure of personal information, and for a shorter time period (no more than 5 years), please get back in touch.