| Espo | Other | 4 | £3m | 23.8% | 2021-08-22 |
| Department for Work & PensionsNew | Other | 1 | £3m | 23.2% | 2024-08-12 |
| UK Shared Business Services Ltd | Other | 1 | £1m | 9.8% | 2016-01-01 |
| Office for National Statistics | Other | 3 | £410k | 3.7% | 2023-08-11 |
| The Water Services Regulation Authority | Other | 6 | £353k | 3.2% | 2022-03-25 |
| Ministry of Defence | Other | 2 | £313k | 2.8% | 2022-06-16 |
| Parliamentary and Health Service Ombudsman | Other | 1 | £295k | 2.7% | 2023-04-19 |
| Surrey PoliceNew | Other | 1 | £271k | 2.5% | 2025-03-13 |
| Joint Procurement Service for Surrey and Sussex Police | Other | 1 | £248k | 2.2% | 2020-04-08 |
| British Transport Police | Other | 2 | £245k | 2.2% | 2022-06-30 |
| Essex County Council | Other | 1 | £220k | 2.0% | 2022-01-06 |
| Worcester City Council | Other | 1 | £179k | 1.6% | 2023-10-23 |
| oneSource | Other | 2 | £140k | 1.3% | 2018-09-17 |
| Police and Crime Commissioner for North Wales Police & North Wales Police | Other | 1 | £128k | 1.2% | 2023-08-07 |
| SE Shared Services | Other | 6 | £118k | 1.1% | 2019-10-31 |
| NHS Supply Chain Coordination | Other | 1 | £99k | 0.9% | 2024-04-02 |
| ORBIT GROUP LIMITED | Other | 2 | £91k | 0.8% | 2023-03-09 |
| Buckinghamshire and Milton Keynes Fire Authority | Other | 2 | £86k | 0.8% | 2025-08-02 |
| Liverpool City Council | Other | 1 | £84k | 0.8% | 2019-02-01 |
| Birmingham City Council | Other | 2 | £82k | 0.7% | 2021-07-12 |
| London Borough of Newham | Other | 2 | £80k | 0.7% | 2023-10-19 |
| Runnymede Borough CouncilNew | Other | 2 | £66k | 0.6% | 2024-12-16 |
| Crown Commercial Service | Other | 1 | £63k | 0.6% | 2018-09-13 |
| Stockton Borough Council | Other | 1 | £60k | 0.5% | 2016-02-25 |
| Ministry of Justice | Other | 1 | £56k | 0.5% | 2020-01-20 |
| London Borough of Barking and Dagenham | Other | 1 | £54k | 0.5% | 2019-10-21 |
| Tendring District Council | Other | 1 | £49k | 0.4% | 2020-01-28 |
| North Yorkshire Police | Other | 1 | £48k | 0.4% | 2021-07-17 |
| Castle Point Borough Council | Other | 1 | £47k | 0.4% | 2023-04-17 |
| Hastings Borough Council | Other | 1 | £46k | 0.4% | 2022-04-29 |
| Office of Rail and Road | Other | 2 | £45k | 0.4% | 2023-02-09 |
| Wealden District Council | Other | 1 | £44k | 0.4% | 2023-07-31 |
| Home Office | Other | 1 | £43k | 0.4% | 2020-06-30 |
| Stonewater Limited | Other | 1 | £40k | 0.4% | 2018-07-16 |
| London Borough of Hounslow | Other | 1 | £40k | 0.4% | 2016-12-13 |
| Single Source Regulations Office | Other | 2 | £39k | 0.4% | 2021-11-01 |
| Essex Fire Authority | Other | 1 | £38k | 0.3% | 2017-04-12 |
| North Hertfordshire District Council | Other | 1 | £37k | 0.3% | 2019-08-22 |
| Leicester City Council | Other | 1 | £35k | 0.3% | 2016-07-19 |
| London Borough of Hackney | Other | 1 | £32k | 0.3% | 2021-06-18 |
| North Northamptonshire Council | Other | 2 | £30k | 0.3% | 2022-11-01 |
| London Borough of Merton | Other | 1 | £30k | 0.3% | 2022-10-19 |
| Bournemouth Christchurch and Poole CouncilNew | Other | 1 | £30k | 0.3% | 2024-11-22 |
| Waverley Borough Council | Other | 1 | £28k | 0.3% | 2024-03-12 |
| London Borough of Tower Hamlets | Other | 1 | £28k | 0.3% | 2016-09-14 |
| Middlesbrough Council | Other | 1 | £28k | 0.3% | 2018-08-31 |
| Stoke-on-Trent City CouncilNew | Other | 1 | £27k | 0.2% | 2024-12-16 |
| capitalEsourcing | Other | 2 | £26k | 0.2% | 2018-10-15 |
| SOUTH YORKSHIRE PASSENGER TRANSPORT EXECUTIVE | Other | 1 | £25k | 0.2% | 2017-10-03 |
| Herefordshire and Worcestershire Health and Care NHS Trust | Other | 1 | £22k | 0.2% | 2022-06-10 |
| Department for Education | Other | 1 | £20k | 0.2% | 2022-05-04 |
| Cornwall Council | Other | 1 | £20k | 0.2% | 2022-12-11 |
| Equality and Human Rights Commission | Other | 1 | £20k | 0.2% | 2018-02-21 |
| London Borough of Hillingdon | Other | 1 | £19k | 0.2% | 2024-03-01 |
| Test Valley Borough Council | Other | 1 | £19k | 0.2% | 2016-05-27 |
| Sheffield City Council | Other | 1 | £15k | 0.1% | 2023-12-13 |
| Blackpool Council | Other | 1 | £15k | 0.1% | 2018-12-21 |
| Rutland County Council | Other | 1 | £15k | 0.1% | 2022-07-19 |
| NHS Resolution | Other | 1 | £14k | 0.1% | 2024-04-02 |
| LGSS | Other | 1 | £13k | 0.1% | 2019-09-16 |
| Darlington Borough Council | Other | 1 | £10k | 0.1% | 2024-03-28 |
| Hampshire County Council | Other | 1 | £5k | 0.0% | 2017-01-16 |
| Welwyn Hatfield Borough CouncilNew | Other | 1 | £0k | 0.0% | 2024-11-25 |
| East Suffolk Council | Other | 1 | £0k | 0.0% | 2023-05-18 |
| Central Bedfordshire Council | Other | 1 | £0k | 0.0% | 2020-12-19 |
| Nottinghamshire Fire and Rescue Service | Other | 1 | £0k | 0.0% | 2017-05-30 |
| Southampton City Council | Other | 1 | £0k | 0.0% | |
| The Police and Crime Commissioner for Surrey | Other | 2 | £0k | 0.0% | |
| Kent Fire & Rescue Service | Other | 1 | £0k | 0.0% | |
| Redditch Borough Council | Other | 1 | £0k | 0.0% | |
| NHS Wales Shared Service Partnership | Other | 1 | £0k | 0.0% | |