| Active Thinking Consultancy Ltd | Malpas | 2023 |
| Active Thinking Limited | Bath | 2007 |
| Active Training & Testing Solutions Limited | Barnsley | 2012 |
| Active Travel Design Ltd | Newton Stewart | 2024 |
| Active Travel Group Bidco Limited | Richmond | 2016 |
| Active Travel Group Midco Limited | Richmond | 2016 |
| Active Travel Limited | London | 2022 |
| Active UK Services Limited | | 2006 |
| Active Utilities Limited | Manchester | 2014 |
| Active Value Investments Ltd | Reading | 2025 |
| Active Vehicle Consultants Limited | Kent | 1995 |
| Active Vtol Crash Prevention Limited | Oswestry | 2017 |
| Active Waste & Landscapes Ltd | Romford | 2025 |
| Active With Power Limited | Milton Keynes | 2024 |
| Active Woodlands Limited | Warwick | 2025 |
| Active Working C.I.C. | Coalville | 2014 |
| Active Workplace Group Ltd | Woodley | 2024 |
| ACTIVE-8 Limited | Retford | 2014 |
| Active-Edge Solutions Ltd | Thatcham | 2022 |
| Active-Itc Ltd | Wirral | 2007 |
| ACTIVE13VENTURES Ltd | Hull | 2021 |
| ACTIVE4LESS Ltd | Harpenden | 2009 |
| ACTIVE4RESEARCH Ltd | West Malling | 2021 |
| ACTIVE8 Aviation Ltd | Slough | 2017 |
| ACTIVE8 Consulting Ltd | Oldham | 2025 |
| Activeast Management (UK) Limited | London | 2009 |
| Activecbt Ltd | Ayr | 2021 |
| Activeclean Ltd | Cambridgeshire | 2005 |
| Activeclearsense Ltd | London | 2016 |
| Activedge Limited | Newcastle | 2007 |
| Activegain Limited | Walton-On-Thames | 1988 |
| Activelife Perks Ltd | Bromsgrove | 2024 |
| Actively BE YOU Ltd | Newcastle | 2024 |
| Actively Connect Ltd | Wimslow | 2025 |
| Actively Engaged Consultancy Ltd | Birmingham | 2019 |
| Activemind.Legal UK Ltd | London | 2019 |
| Activeoffice Limited | Woking | 1992 |
| Activeozone Limited | Wellingborough | 2017 |
| Activepassive Energy Consultants Ltd | Bath | 2019 |
| Activequity Ltd | Oxford | 2022 |
| Activesite Limited | Bath | 2024 |
| Activestone Ltd. | Broadstairs | 2007 |
| Activestream Limited | Manchester | 1992 |
| Activewater Technology Ltd | London | 2023 |
| Activewin Marketing Limited | Hood Street | 2020 |
| Activica Ltd | London | 2023 |
| Activinstinct Holdings Limited | Bury | 2013 |
| Activirosomes Limited | Fersfield | 2017 |
| Activisers Ltd | Haslemere | 2019 |
| Activision Europe, Limited | London | 2003 |
| Activist Team Limited | Cheltenham | 2025 |
| Activiti Consulting Limited | Croydon | 2004 |
| Activity Co (UK) Limited | Worcester | 2003 |
| Activity Gardens Ltd | London | 2022 |
| Activity Scotland Ltd | Pitlochry | 2012 |
| Activity Sports Consultancy Ltd | London | 2025 |
| Activo Limited | Elsham Brigg | 2002 |
| Activo Management Limited | Bridport | 2001 |
| Activon Limited | Irvine | 2019 |
| Activonic Ltd | London | 2010 |
| Activotec Limited | Cambridge | 2010 |
| Activpro Ltd | Bradford | 2017 |
| Activum SG UK Advisors Limited | London | 2014 |
| Activus Limited | Bristol | 1992 |
| Activus Safety Training and Consulting Ltd | Harlow | 2011 |
| Actl Holdings Limited | Birmingham | 2022 |
| Actm Holdings Limited | North Berwick | 2017 |
| Actmac Limited | Barnet | 2019 |
| Actnow Consulting Ltd | Northampton | 2023 |
| Actomac Ltd | Haywards Heath | 2023 |
| Acton Surveyors Ltd | Gravesend | 2024 |
| Acton Barnsley Limited | York | 2016 |
| Acton Brands Limited | Sutton Coldfield | 2020 |
| Acton Bridge Developments Limited | Middlewich | 1996 |
| Acton Capital Advisory Ltd | London | 2025 |
| Acton Chase Associate Limited | Barnsley | 2017 |
| Acton Engineering Limited | Aberdeen | 2005 |
| Acton Grange Properties (West Indies) Limited | Warwickshire | 1988 |
| Acton Health & Safety & Fire Safety Ltd | Wrexham | 2014 |
| Acton HR Limited | Woking | 2020 |
| Acton Manor Properties Limited | Tenterden | 2015 |
| Acton Motors Limited | Potters Bar | 1945 |
| Acton TEC Services Limited | Stockton-On-Tees | 2014 |
| Acton Terrace Management Co. Limited | Wigan | 1991 |
| Actonia Limited | Warwick | 2021 |
| Actonian Consultancy Ltd | Lisburn | 2023 |
| Actor Management Ltd | Hounslow | 2025 |
| Actor Properties Limited | Woodbastwick Norwich | 1996 |
| Actorfactor Limited | Crediton | 2006 |
| Actors in Industry Ltd | London | 2008 |
| Actorsugc Ltd | Evesham | 2025 |
| Actpro Limited | Macclesfield | 2023 |
| Actpsy Consulting Limited | Littlehampton | 2009 |
| Actpsych Marketing Limited | Enniskillen | 2019 |
| Actree Accountancy Ltd | Stockport | 2011 |
| Actro Ltd | London | 2014 |
| Acts 1724 Limited | Birmingham | 2018 |
| Acts Accounting Services Limited | Chelmsford | 2013 |
| Acts Assured Caravan and Trailer Services Ltd | Lincoln | 2013 |
| Acts Consulting Limited | Colchester | 2014 |