| YPO | Other | 11 | £33m | 16.5% | 2025-06-26 |
| Ministry of Justice | Other | 3 | £28m | 14.0% | 2025-03-10 |
| Crown Commercial Service | Other | 8 | £27m | 13.8% | 2022-07-22 |
| Transport for London | Other | 1 | £22m | 11.0% | 2017-02-03 |
| HM Revenue & Customs | Other | 24 | £17m | 8.7% | 2021-04-09 |
| H M REVENUE & CUSTOMS | Other | 12 | £9m | 4.4% | 2025-05-08 |
| HM Land Registry | Other | 2 | £8m | 3.8% | 2025-04-17 |
| Ministry of Defence | Other | 7 | £6m | 3.1% | 2025-01-13 |
| GOVERNMENT PROPERTY AGENCY | Other | 5 | £5m | 2.6% | 2024-11-20 |
| North Western Universities Purchasing Consortium | Other | 2 | £5m | 2.5% | 2023-04-25 |
| NORTH WESTERN UNIVERSITIES PURCHASING CONSORTIUM LIMITED | Other | 1 | £4m | 1.9% | 2019-04-30 |
| UNIVERSITY OF MANCHESTER | Other | 2 | £3m | 1.6% | 2019-05-14 |
| N H S Shared Business Services | Other | 1 | £3m | 1.5% | 2024-02-27 |
| Department for Environment Food & Rural AffairsNew | Other | 1 | £3m | 1.3% | 2025-03-31 |
| University of Sunderland | Other | 2 | £2m | 1.0% | 2022-04-06 |
| UK SHARED BUSINESS SERVICES LIMITED | Other | 15 | £2m | 0.9% | 2026-02-16 |
| Government Property Agency : Cabinet Office | Other | 1 | £2m | 0.9% | 2021-03-03 |
| NHS Supply Chain | Other | 2 | £2m | 0.8% | 2017-10-06 |
| BANK OF ENGLAND | Other | 1 | £2m | 0.8% | 2021-12-17 |
| Department for Work & Pensions | Other | 1 | £1m | 0.7% | 2020-12-02 |
| London Borough of Hammersmith & FulhamNew | Other | 1 | £1m | 0.6% | 2025-12-23 |
| Category ManagerNew | Other | 1 | £1m | 0.6% | 2024-08-19 |
| United Kingdom Hydrographic Office | Other | 1 | £1m | 0.6% | 2018-09-05 |
| Tower Hamlets | Other | 1 | £1m | 0.6% | 2022-06-20 |
| DVSA - Driver and Vehicle Standards Agency | Other | 2 | £1m | 0.5% | 2024-01-19 |
| Yorkshire & Humber Police Procurement | Other | 1 | £1m | 0.5% | 2023-08-24 |
| Epping Forest District Council | Other | 1 | £1m | 0.5% | 2020-01-05 |
| Nottinghamshire County Council | Other | 1 | £1m | 0.5% | 2019-07-31 |
| Intellectual Property Office | Other | 5 | £791k | 0.4% | 2023-08-14 |
| South Yorkshire Police Headquarters | Other | 1 | £750k | 0.4% | 2021-02-17 |
| Foreign Commonwealth and Development Office | Other | 1 | £665k | 0.3% | 2020-09-28 |
| Liverpool City Council | Other | 1 | £600k | 0.3% | 2018-09-28 |
| NHS Blood and Transplant (NHSBT)New | Other | 3 | £570k | 0.3% | 2025-06-24 |
| Nursing And Midwifery Council | Other | 3 | £559k | 0.3% | 2021-04-26 |
| Optivo | Other | 1 | £430k | 0.2% | 2020-03-23 |
| Leicestershire County Council, trading as ESPONew | Other | 2 | £372k | 0.2% | 2026-02-12 |
| Ofgem | Other | 1 | £214k | 0.1% | 2021-01-06 |
| Liverpool School of Tropical Medicine | Other | 4 | £208k | 0.1% | 2022-05-01 |
| FCDO Services | Other | 8 | £192k | 0.1% | 2025-04-30 |
| Grand Union Housing Group | Other | 1 | £169k | 0.1% | 2024-03-13 |
| City of Doncaster Council | Other | 2 | £153k | 0.1% | 2024-01-15 |
| Homes England (the name adopted by the Homes and Communities Agency)New | Other | 1 | £150k | 0.1% | 2026-03-31 |
| Manchester City Council | Other | 1 | £150k | 0.1% | 2019-01-03 |
| West Northamptonshire Council | Other | 1 | £120k | 0.1% | 2023-01-24 |
| Maritime & Coastguard Agency | Other | 4 | £118k | 0.1% | 2018-10-18 |
| University Of The West Of England | Other | 3 | £103k | 0.1% | 2025-09-03 |
| Northumberland County CouncilNew | Other | 1 | £82k | 0.0% | 2025-02-20 |
| Corserv Limited | Other | 1 | £82k | 0.0% | 2020-07-02 |
| Knowsley Council | Other | 1 | £80k | 0.0% | 2022-02-25 |
| Parliamentary and Health Service Ombudsman | Other | 1 | £76k | 0.0% | 2021-02-06 |
| Sedgemoor District Council | Other | 1 | £70k | 0.0% | 2021-06-14 |
| HISTORIC ENGLAND LIMITED | Other | 1 | £68k | 0.0% | 2018-02-09 |
| NHS Property Services LimitedNew | Other | 1 | £59k | 0.0% | 2024-06-12 |
| Doncaster MBC | Other | 1 | £55k | 0.0% | 2021-07-26 |
| York St John University | Other | 1 | £45k | 0.0% | 2023-07-10 |
| Department of Health and Social Care (DHSC) | Other | 1 | £37k | 0.0% | 2023-03-03 |
| The National Archives | Other | 2 | £34k | 0.0% | 2023-01-11 |
| Highways Agency | Other | 1 | £32k | 0.0% | 2018-04-23 |
| NHS South West - Acutes | Other | 1 | £30k | 0.0% | 2017-08-28 |
| Radioactive Waste Management Limited | Other | 2 | £28k | 0.0% | 2020-05-29 |
| The Charity Commission For England And Wales | Other | 1 | £24k | 0.0% | 2021-03-05 |
| Met Office | Other | 1 | £12k | 0.0% | 2016-12-23 |
| UK Hydrographic Office | Other | 1 | £10k | 0.0% | 2021-11-17 |
| Hampshire County CouncilNew | Other | 2 | £0k | 0.0% | 2024-12-24 |
| Citizen Housing Group Ltd | Other | 1 | £0k | 0.0% | 2022-07-18 |
| Department for Transport | Other | 1 | £0k | 0.0% | |
| FE Southern Regional College | Other | 2 | £0k | 0.0% | |
| NHS SHARED BUSINESS SERVICES LIMITED | Other | 4 | £0k | 0.0% | |
| HEPCW (Higher Education Purchasing Consortium Wales) | Other | 2 | £0k | 0.0% | |
| London Borough of Hackney | Other | 1 | £0k | 0.0% | |
| Grand Union Housing Group Ltd | Other | 1 | £0k | 0.0% | |
| The Common Services Agency (more commonly known as NHS National Services Scotland) (NSS) | Other | 1 | £0k | 0.0% | |
| Cornwall Council | Other | 1 | £0k | 0.0% | |
| UK Research and Innovation | Other | 1 | £0k | 0.0% | |
| DERBY CITY COUNCIL | Other | 2 | £0k | 0.0% | |
| NHS Supply Chain Coordination | Other | 1 | £0k | 0.0% | |
| Stoke-on-Trent City Council | Other | 1 | £0k | 0.0% | |