| Acoustic Technology Ltd. | West Midlands, England | 2025 |
| Acoustic Treatment UK Ltd | High Peak | 2025 |
| Acoustics Explorer Ltd. | West Midlands, England | 2025 |
| Acoustics Installations Ltd | Iver Heath | 2008 |
| Acoustiks Ltd | Manchester | 2018 |
| Acoustofab Ltd | London | 2023 |
| Acovelli Ltd | Southampton | 2022 |
| Acowhite Limited | Essex | 2025 |
| ACP Engineering Limited | Maidstone | 2020 |
| ACP Facade Services Ltd | Coventry | 2019 |
| ACP LAB Ltd | Coalville | 2024 |
| ACP Realisations Limited | Watford | 2002 |
| ACP Solutions Limited | Nailsworth | 1996 |
| Acpc Healthcare UK Ltd | London | 2020 |
| Acpl London Ltd | Batley | 2019 |
| Acps Automotive Services Ltd | Birmingham | 2022 |
| ACQ Import and Export Ltd | London | 2022 |
| Acqua Eterna Ltd | London | 2012 |
| Acqua Nordica Ltd | London | 2015 |
| Acquapuro Limited | East Grinstead | 2019 |
| Acqui General Trading Limited | Bristol | 2011 |
| Acquire Print Limited | Northolt | 2019 |
| Acquire Sign Ltd. | Cardiff | 2016 |
| Acquire-X Limited | Dundee | 2024 |
| Acquired Group Services Limited | Croydon | 2009 |
| Acquisition 395447313 Limited | Kingston Upon Thames | 1959 |
| Acquitaine Limited | Stockport | 2005 |
| ACR Bidco Limited | Basingstoke | 2025 |
| ACR Composites Limited | Leeds | 2016 |
| ACR Electrical (Fife) Ltd | Dunfermline | 2020 |
| ACR Fabrications Ltd | Shifnal | 2022 |
| ACR Repairs Limited | London | 2012 |
| ACR Signs Limited | Leicester | 2017 |
| ACR Transport Ltd | Harlow | 2019 |
| Acra Screed Limited | Skipton | 2005 |
| Acrabuild Limited | Market Deeping | 1978 |
| Acrafab Limited | Glasgow | 2004 |
| Acrastyle Limited | Ulverston | 1962 |
| Acrc Solutions Ltd | London | 2026 |
| Acre & Holt Ltd | Frome | 2005 |
| Acre Engineering Services Ltd | Anstruther | 2022 |
| Acre Enterprises (ARW) Limited | Woodbridge | 2024 |
| Acre Joinery Limited | Norwich | 1977 |
| Acre North West Limited | Lancaster | 2025 |
| Acreage Homes Ltd | Birmingham | 2017 |
| Acrefine Engineering Services Ltd | London | 2008 |
| Acrepress Limited | 27 Greenwood Place | 1988 |
| Acres Dairy Limited | Chester | 2009 |
| Acres Engineering Limited | Derby | 2002 |
| Acres Retail Ltd | Swindon | 2020 |
| Acres Signs & Graphics Limited | Ashbourne | 2014 |
| Acrilica Ltd | Birmingham | 2022 |
| Acrison International (UK) Limited | Salford | 2009 |
| Acritudo Industries Limited | Sevenoaks | 2019 |
| Acrivarn Limited | Leeds | 1967 |
| Acro Aircraft Seating Limited | Crick | 2006 |
| Acro Engineering Ltd | Stockport | 2025 |
| Acro Technology Industry Co., Ltd | Kington | 2015 |
| Acro Yoga Travels Limited | Cardiff | 2022 |
| Acrolithos Ltd | London | 2021 |
| Acron Aviation Training Solutions Limited | Altrincham | 2006 |
| Acron Engineering Services (UK) Ltd | Morden | 2023 |
| Acrona Engineering Limited | Witney | 2001 |
| Acropolis Audio Ltd | Cambridge | 2018 |
| Acropolis Cebt Ltd | London | 2017 |
| Acropolis Patisserie Limited | London | 2023 |
| Acropolis Street Food (Catering) Ltd | Newcastle Upon Tyne | 2018 |
| Acrosentec UK Ltd | Hull | 2024 |
| Acrospire Products Limited | Basingstoke | 2017 |
| Acrospire Solutions Limited | Basingstoke | 2012 |
| Across Industrial Doors Ltd | Warrington | 2020 |
| Across Medical Ltd | London | 2023 |
| Across- the- Board Games CIC | Saltburn-By-The-Sea | 2021 |
| Acroterium Limited | Banstead | 2018 |
| Acrovision Limited | St.Albans | 2005 |
| Acrow Galvanizing Limited | West Midlands | 1979 |
| Acru Electric Tool Manufacturing Co. Limited(The) | Cheadle | 1954 |
| Acruk Enterprise Limited | London | 2017 |
| Acryl Limited | Plymouth | 2021 |
| Acrylic Aquariums UK Limited | Lydney | 2016 |
| Acrylic Canopy UK Ltd | Bury | 2021 |
| Acrylic Crafts Ltd | South Shields | 2009 |
| Acrylic Design Holdings Limited | London | 2018 |
| Acrylic Design Watford Limited | Northampton | 2018 |
| Acrylic Fabrications Limited | Corby | 2006 |
| Acrylic Hub Ltd | Oldham | 2024 |
| Acrylic Parts Co., Ltd | Beckenham | 2017 |
| Acrylic Pixel Ltd | Milton Keynes | 2022 |
| Acrylidex Ltd | London | 2010 |
| Acrylux Limited | Tiverton | 2000 |
| ACS Agricultural Supplies Limited | East Hanningfield | 1980 |
| ACS Aviation Limited | Paisley | 2007 |
| ACS Building Products Limited | Leeds | 2015 |
| ACS Carpentry Ltd | Dunmow | 2025 |
| ACS Clothing Limited | Motherwell | 1997 |
| ACS Compressed Air Technology Ltd. | Aylesbury | 2011 |
| ACS Controls Ltd | Londonderry | 2014 |
| ACS Enterprise Group Ltd | London | 2024 |
| ACS Fabrications Ltd | Tewkesbury | 2024 |
| ACS Facades Limited | Leeds | 2019 |