| Actryx Ltd | London | 2022 |
| Actsense UK Private Limited | London | 2023 |
| Actservices Ltd | Epping | 2013 |
| Actsharp Consulting Ltd | Manchester | 2025 |
| Actsight Limited | Reading | 2025 |
| Actsow the Film Ltd | London | 2022 |
| Actsure Solutions Ltd | London | 2025 |
| Actt Digital Ltd | Wallsend | 2026 |
| Actt Ltd | Hatfield | 2025 |
| Acttrident Ltd. | Reading | 2026 |
| Actuait Ltd | London | 2026 |
| Actual Analytics Limited | Edinburgh | 2009 |
| Actual Corners Limited | Washington | 2024 |
| Actual Hire Ltd | Wolverhampton | 2025 |
| Actual IT Solutions Ltd. | Leeds | 2004 |
| Actual Radio Ltd | Basildon | 2016 |
| Actual Records Ltd | London | 2025 |
| Actual Sound Label Limited | Musselburgh | 2025 |
| Actual Strategies Limited | South Yorkshire | 2003 |
| Actual Users Ltd | London | 2008 |
| Actualise Consulting Limited | Cambridge | 2014 |
| Actualised Living Limited | London | 2011 |
| Actualize Consulting Group Ltd | Guildford | 2023 |
| Actualize Intelligence Ltd | London | 2025 |
| Actualize UK Limited | Woking | 2009 |
| Actualizer Ltd | London | 2024 |
| Actually Data Analytics Limited | London | 2022 |
| Actually Data Limited | London | 2015 |
| Actually Delicious Ltd | Slough | 2024 |
| Actually Films Limited | London | 2013 |
| Actually Playable Ltd | London | 2025 |
| Actually Software Ltd | London | 2024 |
| Actualyse Co. Ltd | London | 2023 |
| Actuare Limited | Harpenden | 1997 |
| Actuarial Apps Limited | Wokingham | 2015 |
| Actuarial Collaborative Technology Ltd | St. Anne'S | 2025 |
| Actuarial Computing Limited | Ballyshannon | 1986 |
| Actuarial Intelligence Ltd | Tring | 2020 |
| Actuarial Services Limited | Shrewsbury | 2019 |
| Actuarial Software Re-Engineering Services Limited | | 2006 |
| Actuarial Solutions Limited | Surrey | 1995 |
| Actuarist Ltd | London | 2017 |
| Actuate Analytics Ltd | Staffordshire | 2006 |
| Actuate Digital Limited | Crewe | 2019 |
| Actuate Finance Ltd | London | 2022 |
| Actuate IT Limited | Loanhead | 2007 |
| Actuly Limited | Cardiff | 2024 |
| Actum Advisory Ltd | Hemel Hempstead | 2026 |
| Actum Group Limited | London | 2021 |
| Actum Ltd | London | 2022 |
| Actuo Ltd | South Queensferry | 2026 |
| Actupnorth Limited | Altrincham | 2012 |
| Acture Ltd | Oadby | 2021 |
| Actureon Ltd | Guildford | 2025 |
| Acturis Limited | London | 2000 |
| Actus Healthcare Limited | Rainham | 2015 |
| Actus Verto Technologies Limited | Widnes | 2026 |
| ACTUS108 Ltd | London | 1999 |
| Actusedge Limited | London | 2026 |
| ACU IT Solutions Limited | Glasgow | 2020 |
| Acuative Limited | Uxbridge | 1999 |
| Acube Consultants Ltd | South Croydon | 2012 |
| Acube Digital Limited | Reading | 2024 |
| Acube Limited | London | 2018 |
| Acube Systems Limited | Woodford Green | 2022 |
| Acubed IT Solutions Limited | London | 2019 |
| Acubeproductions Ltd | Orpington | 2024 |
| Acucare Systems Ltd | Brentford | 2025 |
| Acucarex Ltd | Brentford | 2025 |
| Acucomm Limited | Kidderminster | 2012 |
| Acuconnect Ltd | Covent Garden | 2020 |
| Acuda Ltd | Northampton | 2021 |
| Acudantia Limited | Herts | 2007 |
| Acudata Limited | London | 1996 |
| Acue Ltd | Weybridge | 2020 |
| Acuflo Ltd | Ilkley | 2024 |
| Acuida Systems Ltd | London | 2025 |
| Acuigen Europe Limited | Bedford | 2020 |
| Acuiot Limited | London | 2026 |
| Acuitas Business Intelligence Limited | Wantage | 2023 |
| Acuitas Consultants Limited | Tring | 2024 |
| Acuitas Limited | Sunbury-On-Thames | 2011 |
| Acuitech Solutions Ltd | Manchester | 2018 |
| Acuiti Labs Ltd. | London | 2014 |
| Acuiti Solutions Ltd | Holsworthy | 2013 |
| Acuity AI Limited | Twickenham | 2024 |
| Acuity Analytics Ltd | London | 2018 |
| Acuity Applied Limited | London | 2016 |
| Acuity Digital Services Limited | Hassocks | 2014 |
| Acuity Enterprises Limited | Bromborough | 2007 |
| Acuity Global Limited | Shrewsbury | 2006 |
| Acuity HCM Consulting Ltd | Harrow | 2021 |
| Acuity Internet Limited | High Wycombe | 2003 |
| Acuity Origin Limited | Warrington | 2023 |
| Acuity Productions UK Ltd | London | 2018 |
| Acuity Risk Management Limited | London | 2019 |
| Acuity Software Limited | High Wycombe | 2003 |
| Acuity Software Technologies Limited | High Wycombe | 2001 |
| Acuity Solutions Limited | London | 1996 |
| Acuity Systems Limited | Wokingham | 2012 |