| Acquis Media Limited | Stourbridge | 2004 |
| Acquisition 395196221 Limited | London | 2011 |
| Acquisition Forms Ltd | London | 2017 |
| ACR Agency Ltd | Abingdon | 2022 |
| ACR Creations Ltd | Birmingham | 2023 |
| ACR Golf Limited | Alnwick | 2002 |
| Acr:Mcr Limited | Manchester | 2016 |
| Acre 1224 Limited | Kingston Upon Thames | 2020 |
| Acrfc Trading Limited | Amersham | 2016 |
| Acrk Media Ltd | Ashby-De-La-Zouch | 2022 |
| Acrobat Productions Limited | Berkhamsted | 2004 |
| Acrobatic Adventures CIC | Bath | 2024 |
| Acrobaticarts Circus Entertainment Ltd | Middlesbrough | 2022 |
| Acrobaticpoly Ltd | London | 2024 |
| Acrobody Ltd | Henfield | 2019 |
| Acrodance UK Limited | Nelson | 2022 |
| Acroflex Dance Academy Ltd | Durham | 2023 |
| Acronex Sports Management Limited | London | 2020 |
| Across the Pond Fitness Limited | Abingdon | 2020 |
| Across the Pond Theatrical Management Ltd | Romford | 2025 |
| Acrotex Limited | Eastbourne | 1998 |
| Acrotrix Ltd | Watford | 2019 |
| Acrotrix Watford Ltd | Watford | 2022 |
| Acrylic Sports Coatings Ltd | Northampton | 2010 |
| Acrylicize Limited | London | 2004 |
| ACS Golf Limited | London | 2025 |
| ACS Random Ltd | Carshalton | 2014 |
| ACS Trustee 1 Ltd | Aylesbury | 2024 |
| ACS Trustee 2 Ltd | Aylesbury | 2024 |
| Acsod Ltd | Ipswich | 2026 |
| ACT & Impact Ltd | Stockport | 2025 |
| ACT (Action for the Community and Town) at the Cheethams Limited | Blackburn | 2007 |
| ACT 2 Performing Arts CIC | Chinley | 2025 |
| ACT 3 Theatre Company CIC | Sawbridgeworth | 2024 |
| ACT 5 Arts Ltd | Farnham | 2026 |
| ACT Drama Limited | Clacton-On-Sea | 2025 |
| ACT Entertainment Group Limited | London | 1955 |
| ACT Events Ltd | Chester | 2026 |
| ACT Mgmt Limited | London | 2025 |
| ACT NOW Productions Ltd | Seaview | 2023 |
| ACT One Roleplay Ltd | London | 2024 |
| ACT Productions Limited | London | 1994 |
| ACT Royale Studios Ltd | London | 2025 |
| ACT Scotland Ltd | Motherwell | 2023 |
| ACT Self Defence CIC | Waterlooville | 2022 |
| ACT Theatre School Limited | Denny | 2025 |
| ACT TOO Stage School Ltd | Burgess Hill | 2006 |
| ACT TOO Theatre Company Ltd | Melton Mowbray | 2025 |
| ACT Trading Activities Limited | Plymouth | 2023 |
| ACT Two Entertainment Ltd | London | 2026 |
| ACT Two MT Ltd | Droitwich | 2026 |
| ACT UP! Newham C.I.C. | Forest Gate | 2015 |
| ACT4THEATRE Limited | Potters Bar | 2024 |
| Acta Community Theatre Ltd | Bedminster | 1987 |
| Acta Diurna Media Ltd | Hull | 2020 |
| Actability Ltd | Bishop'S Stortford | 2005 |
| Actafit Ltd | London | 2021 |
| Acthorpe Sporting Limited | Market Rased | 2012 |
| Actify Sports Limited | Grimsby | 2015 |
| Actify Training and Technology CIC | Glasgow | 2016 |
| Actilife Limited | London | 2011 |
| Acting Lincs CIC | Grimsby | 2025 |
| Acting Magic Limited | Selby | 2012 |
| Acting Moon Events Limited | Bexhill On Sea | 2014 |
| Acting OUT Drama School Limited | Musselburgh | 2014 |
| Acting OUT Productions Ltd | East Grinstead | 2024 |
| Acting UP Arts CIC | Leek | 2026 |
| Acting UP Childrens Theatre Company Limited | Newcastle Upon Tyne | 2014 |
| Acting UP Drama School Limited | Fareham | 2016 |
| Action Adventure Activities Limited | Stirlingshire | 2005 |
| Action Annabel Stunts Limited | Dorchester | 2019 |
| Action Black UK Limited | London | 2026 |
| Action Cat Ltd | Hove | 2004 |
| Action Dynamics Limited | Gateshead | 2021 |
| Action Fitness Limited | Stockton On Tees | 2025 |
| Action for Arts Trust Ltd | Clwyd | 2002 |
| Action for Children's Arts | Cambridge | 1999 |
| Action Hero | Bristol | 2018 |
| Action Indoor Sports Birmingham CIC | Lichfield | 2014 |
| Action Petz Swansea Ltd | Swansea | 2019 |
| Action Plus Media Limited | Herne Bay | 2006 |
| Action Reaction Theatre Company CIC | Coventry | 2026 |
| Action Reaction Training Ltd | Carlisle | 2015 |
| Action Rochdale Ltd | Rochdale | 2013 |
| Action Space London Events Limited | London | 1984 |
| Action Sports Music Limited | London | 2017 |
| Action Stadium UK Limited | London | 2018 |
| Action TC Ltd | East Grinstead | 2025 |
| Action Theatre (Italy) Ltd | Glasgow | 2026 |
| Action Theatre Ltd | Abergele | 2022 |
| Action Theatre Scotland Ltd | Glasgow | 2022 |
| Action Training Courses Limited | Banwell | 2008 |
| Action-Ants Limited | Penrith | 2010 |
| ACTION8STUNTS Limited | Liverpool | 2025 |
| Actioncore Ltd | London | 2025 |
| Actiontrack Performance Company Limited | Taunton | 2001 |
| Actiontrax Limited | Aylesford | 2003 |
| Activ Photo Limited | London | 2000 |
| Activ Solution Limited | London | 2008 |
| ACTIV-8 Adventure Ltd | Norfolk | 2004 |