| Acton Bridge Cruising Club Limited | Northwich | 1964 |
| Acton Elle London Limited | London | 2022 |
| Acton Gardens Development Trust | London | 2020 |
| Acton Hair & Beauty Ltd | London | 2019 |
| Acton Hair Salon Ltd | London | 2018 |
| Acton Maintenance Ltd | Llandeilo | 2025 |
| Acton Property Management Ltd | London | 2011 |
| Acton Property Services Ltd | London | 2015 |
| Acton Recycling Community | London | 1998 |
| Acton Street Freehold Ltd | Windsor | 2016 |
| Acton Town DRY Cleaners Ltd | London | 2023 |
| Actons Lock RTM Company Limited | London | 2010 |
| Actorad Limited | Sidcup | 2013 |
| Actors Guild of UK Nollywood Limited | Hemel Hempstead | 2015 |
| Actors' Creative Team Limited | London | 2001 |
| Actrea Capital Ltd | London | 2011 |
| Acts (Africa Christian Textbooks) International | Belfast | 2025 |
| Acts 2:42 Ministries | Corby | 2008 |
| Acts Churches UK | Weybridge | 2018 |
| Acts London | London | 2013 |
| Acts of Faith Ministries Limited | Thurleigh | 2006 |
| Actso Limited | Basildon | 2012 |
| Actual Film Ltd | | 2001 |
| Actual People Development Ltd | Lichfield | 2009 |
| Actual Talent Limited | London | 2023 |
| Actual U Ltd | Leeds | 2024 |
| Actuarial Modelling Ltd | London | 2007 |
| Actuate UK Limited | Sevenoaks | 2020 |
| Acturus Ltd | Cinderford | 2015 |
| Actv Eight Ltd | London | 2024 |
| Acudr.S Ltd | Redruth | 2021 |
| Acuhair HQ Ltd | Trowbridge | 2025 |
| Acuherbs (TCM) Limited | Weymouth | 2015 |
| Acuity Compliance Limited | Merseyside, St Helens | 2021 |
| Acumen Coaching Ltd | Cardiff | 2001 |
| Acumen Community Buildings Ltd | Houghton Le Spring | 2017 |
| Acumen House Holdings Limited | Reading | 2017 |
| Acumen Limited | London | 1997 |
| Acumen Strategic Partners Ltd | Bury St. Edmunds | 2019 |
| ACUMEN7 Limited | Wallingford | 2003 |
| Acumist Consulting Limited | London | 2016 |
| Acumist Limited | Windlesham | 2013 |
| Acupuncture for the Future Limited | Birmingham | 2014 |
| Acupunture Plus UK Ltd | Chester Le Street | 2009 |
| Acurelax Centre Ltd | Solihull | 2022 |
| Acurelax Spa & Acupuncture Ltd | Walsall | 2022 |
| Acut Above the Rest Ltd | Nottingham | 2019 |
| Acutabove Hair Salon Limited | Caldicot | 2010 |
| Acute Business Advisory Ltd | Derby | 2021 |
| Acute Consulting Services Ltd | Bolton | 2020 |
| Acute Look Limited | Southampton | 2007 |
| Acute Ltd | Marlow | 2025 |
| Acutebeauty Limited | Ipswich | 2024 |
| Acuvivo Medical Writing Limited | Brighton | 2021 |
| Acuwellness Ltd | Wembley | 2013 |
| ACV Consulting Limited | London | 2009 |
| ACW Funerals Limited | Caerphilly | 2021 |
| AD & MAK Ltd | Leeds | 2024 |
| AD & V Ltd | Wembley | 2014 |
| AD 1337 Ltd | London | 2023 |
| AD 47 Ltd | London | 2021 |
| AD Alpha Solutions Ltd | Manchester | 2016 |
| AD Art Limited | Sheffield | 2008 |
| AD Beauty Base Ltd | Mitcham | 2025 |
| AD Blue Stone Ltd | Grays | 2022 |
| AD Bonum Limited | Newcastle-Upon-Tyne | 2019 |
| AD Car Care Farnham Ltd | Surrey | 2016 |
| AD Car Wash Ltd | Rushden | 2024 |
| AD Carpets London Ltd | Rickmansworth | 2011 |
| AD Clavum Limited | Northwich | 2026 |
| AD Collection Services Ltd | Keston | 2018 |
| AD Cube Consulting Limited | Milton Keynes | 2017 |
| AD Deliveries Ltd | Paisley | 2025 |
| AD Design & Build Ltd | London | 2020 |
| AD Eco Services Ltd | Newport | 2022 |
| AD Equine Limited | Sunderland | 2019 |
| AD FITNESS121 Limited | London | 2024 |
| AD Hair 2026 Ltd | Bushey | 2026 |
| AD Hair and Beauty Limited | Yeovil | 2013 |
| AD Haircut Swindon Ltd | Swindon | 2018 |
| AD Hazell Limited | St. Albans | 2014 |
| AD HOC Associates Limited | Truro | 2003 |
| AD HOC Global Limited | London | 2012 |
| AD ID Research and Analytics Limited | London | 2024 |
| AD Impex Ltd | Tipton | 2025 |
| AD Leisure Group Ltd | Mansfield | 2022 |
| AD Libitum Business Coaching Limited | Yeovil | 2010 |
| AD London Ltd | Cockfosters | 2016 |
| AD Management Opco-A Ltd | Peterborough | 2025 |
| AD Maximam Ltd | Gravesend | 2019 |
| AD Mayoh V'Esrim Limited | Salford | 2017 |
| AD Nails & Beauty Limited | Pontefract | 2026 |
| AD Nails & Spa Ltd | Airdrie | 2025 |
| AD New Milton Ltd | New Milton | 2019 |
| AD Optical Ltd | Leeds | 2010 |
| AD Optimal Solutions Ltd | Bromley | 2024 |
| AD Ostium Ltd | Derby | 2021 |
| AD Predictive Services Limited | Basildon | 2013 |
| AD Private Limited | Glasgow | 2018 |
| AD Properties India Limited | Stevenage | 2024 |