§ Contractor/consultancy firms employed by the prison service IT Group since agency status in 1993
- Interskill (formerly VNG Nationwide/Winway)
- Software Personnel plc
- Capita Recruitment Services
- Certes Computing Ltd. (Previously Alpha-Rac)
- Daymount Computing Ltd.
- CSS Trident
- S. Com Computer Systems Engineers Ltd.
- DBI Associates Ltd.
- Hays Accounting Personnel
- Hewitson Walker
- Inline PKG
- SQA Software Quality Assurance Ltd.
- Hoskyns
- Triad
- ABT International
- Frost Berkley Associates
- Hunterskill
- Myriad
- ICS Ltd. (Independent Computer Solutions)
- Cornwell Affiliates Ltd.
- Hoskyns Group Plc
- Accountancy Personnel
- ACT Ltd.
- PA Consulting
- Ernst & Young
- William J. Cooper Associates
- Sema Group
- Oscar Faber
- Logica
- John Matchett Ltd.
- Computacentre
- Bull Information Systems
- Windsor Consulting
- ADS Technologies
- CIAS
- Tetra Ltd.
- KPMG
- Redra Ltd.
- Lorien Personnel
- Ess-Comm
- Frost Berkley
- Computer People