| Active Financial Ltd | Milton Keynes | 2024 |
| Active Financial Partners Limited | Waterlooville | 2001 |
| Active Financial Planners Limited | Stockton-On-Tees | 2000 |
| Active Financial Planning Ltd | Eastbourne | 2018 |
| Active Fitzroy Nominees Limited | London | 2020 |
| Active Fleet Management Limited | Manchester | 2018 |
| Active GP II Limited | Edinburgh | 2014 |
| Active GP Limited | London | 2005 |
| Active Group Global Ltd | Salisbury | 2025 |
| Active Group Holdings Limited | Norwich | 2026 |
| Active Impex Ltd | London | 2007 |
| Active Individual Mortgage Solutions Limited | Chester Le Street | 2020 |
| Active Investment Consulting Limited | Redhill | 2014 |
| Active Investment Managers Limited | Hull | 1987 |
| Active Investments (Reading) Limited | Reading | 1995 |
| Active Investments North East Ltd | Langley Park | 2024 |
| Active Learning Group Limited | Peterborough | 2025 |
| Active Leisure Caravans Limited | Newcastle Under Lyme | 2023 |
| Active Management Centre Ltd | Kings Langley | 2026 |
| Active Manco Limited | London | 2020 |
| Active Money Solutions Ltd | Belfast | 2012 |
| Active Mortgage Services Limited | Guisborough | 2002 |
| Active Mortgage Solutions (East Anglia) Limited | Norwich | 2005 |
| Active Mortgages (UK) Ltd | Fareham | 2014 |
| Active Neuro Limited | London | 2020 |
| Active PAY Ltd | Manchester | 2026 |
| Active Pensions Limited | Westerham | 2012 |
| Active Pharmacare Holdings Ltd | Salford | 2023 |
| Active Physio Care Limited | Stockton-On-Tees | 2024 |
| Active Plumbing Supplies Holdings Limited | Malmesbury | 2021 |
| Active Solutions Group Limited | Liverpool | 2020 |
| Active Technologies Limited | Evesham | 2016 |
| Active Travel Group Limited | Richmond | 2016 |
| Active Underwriting Specialists Limited | London | 2006 |
| Active Value Limited | Kent | 2002 |
| Active Vision Media Ltd | London | 2025 |
| Active Wealth Estates Ltd | Waterlooville | 2015 |
| Active Young People Limited | London | 2020 |
| ACTIVE8 Minds Group Limited | Emsworth | 2024 |
| Activeed Group Ltd | Melksham | 2025 |
| Activeedge Holdings Ltd | Oxted | 2025 |
| Activeplan Holdings Limited | Derby | 2017 |
| Activerisk Group Limited | London | 2020 |
| Activerisk Limited | London | 2021 |
| Activinsights Holdings Limited | Huntingdon | 2024 |
| Activitee Group Ltd | Birmingham | 2025 |
| Activities Industry Mutual Limited | London | 2005 |
| Activpayroll Group Limited | Manchester | 2019 |
| Activtrades PLC | London | 2005 |
| Activtrades SPV NO 1 Ltd | London | 2021 |
| Activus Wealth Ltd | London | 2014 |
| Actnow Mortgages Ltd | Corby | 2021 |
| Acton Brothers Limited | London | 2023 |
| Acton Financial Services Ltd | Wrexham | 2021 |
| Acton Grange Investments Limited | Coventry | 2020 |
| Acton Group Ltd | Stafford | 2017 |
| Acton Holdings Limited | Uxbridge | 2021 |
| Acton International Limited | Twickenham | 2002 |
| Acton Main Ltd | Croydon | 2022 |
| Acton Private Capital Ltd | Manchester | 2026 |
| Acton Rock Ltd | Taunton | 2024 |
| Actron Asset Recovery Limited | London | 2017 |
| Acts Partnership Holdings Limited | Glasgow | 2016 |
| Actsev & Associates Limited | Edgware | 2012 |
| Actuali Ltd | Glasgow | 2022 |
| Actually Mortgages Limited | Preston | 2008 |
| Actuarial Advisory Services Limited | Hornchurch | 2011 |
| Actuarial Analytics Limited | Wirral | 2018 |
| Actuarial and Quantitative Services Limited | Stoke-On-Trent | 2014 |
| Actuarial Associates Ltd | London | 2020 |
| Actuarial Collaborative Solutions Ltd | Lytham, St. Anne'S | 2024 |
| Actuarial Contractors Limited | London | 2007 |
| Actuarial Guru Ltd | Orpington | 2011 |
| Actuarial Risk Management International Limited | Richmond | 2024 |
| Actuarial Risk Management UK Limited | Manchester | 2024 |
| Actuaries for Lawyers (2013) Ltd | Chippenham | 2012 |
| Actuary Forex Global Limited | London | 2021 |
| Actuary MAN Ltd | Watford | 2023 |
| Actuate Mortgages Ltd | Bishop Auckland | 2025 |
| Actuit Limited | Ditchling | 2016 |
| Actura Capital Ltd | Ellesmere Port | 2026 |
| Acturis Finance Limited | London | 2013 |
| Acturis Management Services Limited | London | 2024 |
| Acturis Midco Limited | London | 2024 |
| Acturis Worldwide Limited | London | 2024 |
| Actus Risk Group Ltd | Sheffield | 2023 |
| Actus Risk Management Services Ltd | Sheffield | 2018 |
| Actuverse Ltd | Wimborne | 2024 |
| ACU Capital Ventures Ltd | London | 2025 |
| Acube Capital Limited | London | 2013 |
| Acubens Management Ltd | Westbury | 2014 |
| Acuhold Limited | Manchester | 2013 |
| Acuiti Group Limited | London | 2019 |
| Acuitus Consulting Ltd | London | 2014 |
| Acuity Capital Limited | Bromyard | 2019 |
| Acuity Capital SPV Limited | Bromyard | 2021 |
| Acuity Care Group Limited | Nottingham | 2020 |
| Acuity Care Holdings Limited | Nottingham | 2020 |
| Acuity Commodities Limited | Coventry | 2015 |
| Acuity Corporate Partners Limited | London | 2018 |