| Aceplan Player Development Ltd | Waltham Abbey | 2023 |
| Acer & Camellia Limited | Bury St. Edmunds | 2024 |
| Acer Design Limited | Egham | 1993 |
| Acerte Limited | Leicester | 2008 |
| Aces Event Management Ltd | Leicester | 2017 |
| Aces Gym Limited | London | 2021 |
| Aces High Aviation Gallery Limited | Abingdon | 2003 |
| Aces High Fine Art Limited | Abingdon | 2003 |
| Aces Indoor Golf Ltd | Southampton | 2022 |
| Aces Tattoo Studio Ltd | Cardiff | 2023 |
| Aces Vibe Ltd | Coventry | 2014 |
| Aces Weekly Limited | Hertford | 2011 |
| Aceso Clinic Ltd. | Newport-On-Tay | 2017 |
| Acestars Limited | Basingstoke | 2002 |
| Acett Ltd | Craigavon | 2021 |
| Acevedo-Jones Designs Ltd | London | 2014 |
| ACF Teambuilding and Events Ltd | Bristol | 2012 |
| ACG & LC Limited | Bridgwater | 2021 |
| ACG Future Limited | Bristol | 2018 |
| Acgm Future Ltd | Bristol | 2022 |
| Acgs Investments Limited | Luton | 2024 |
| ACH Consultancy Ltd | Dorchester | 2019 |
| Achievaball Limited | Earlston | 2022 |
| Achieve Arts Agency Limited | Attleborough | 2021 |
| Achieve Fitness Ltd | Cheshire | 2000 |
| Achieve Functional Fitness Ltd | London | 2020 |
| Achieve Goals Ltd | Longfield | 2024 |
| Achieve Lifestyle | Egham | 2010 |
| Achieve Pilates Ltd | London | 2025 |
| Achieve With Abbie Ltd | Caerphilly | 2025 |
| Achievement in Mind Ltd. | Halifax | 2013 |
| Achievement Shawlands Ltd | Ayr | 2019 |
| Achieving Solutions Limited | Basingstoke | 2005 |
| Achikava Health Clubs 2 Limited | London | 2022 |
| Achikava Health Clubs Limited | Birmingham | 2016 |
| Achikolo Global Limited | London | 2026 |
| Achilles Triumph Ltd | London | 2025 |
| Achoiring Voices Ltd | Romsey | 2025 |
| Achota ONU Ltd | Harlow | 2019 |
| Achresis Arts Limited | Woodbridge | 2026 |
| Achunky Limited | London | 2019 |
| Acid Clutch Productions Limited | London | 2009 |
| Acid Jazz Records Limited | Brentwood | 1991 |
| Acid Jungle Ltd | Truro | 2025 |
| Acidmonkey Limited | London | 2006 |
| Acik Ltd | Manchester | 2020 |
| ACK Productions Limited | Belfast | 2009 |
| ACK Sports Ltd | Huddersfield | 2020 |
| Ackc Cricket Ltd | Stirling | 2018 |
| Ackerman Studios Ltd. | London | 2016 |
| Acklam Rugby Club Limited | Middlesbrough | 1980 |
| Acklode Limited | London | 1988 |
| Acklowe Ltd | Plymouth | 2023 |
| Ackroyd and Harvey Limited | Dorking | 2013 |
| Ackroyd Pianos Limited | Somerset | 2011 |
| Ackworth Rambling School of Excellence Ltd | Pontefract | 2020 |
| ACL Collective CIC | Bedford | 2024 |
| Aclb Prints Ltd | London | 2024 |
| ACM Group Ltd | Edgware | 2024 |
| ACM Leisure Limited | Derby | 2020 |
| ACM Management Services Limited | Weston-Super-Mare | 2012 |
| Acmagic Ltd | Louth | 2026 |
| Acme Atelier Ltd | Forres | 2023 |
| Acme Corporation Limited | London | 2013 |
| Acme Football Ltd | Kington | 2021 |
| Acme Ideas (22) Limited | Belfast | 2020 |
| Acme Ideas Limited | Belfast | 2004 |
| Acme Initiative Limited | London | 2025 |
| Acol Bridge Club Limited | London | 2017 |
| Acorn Community Theatre Limited | Worksop | 2005 |
| Acorn Contract Services Ltd | Liverpool | 1998 |
| Acorn Creative Enterprises Ltd. | Clackmannanshire | 2003 |
| Acorn Entertainments Limited | Cirencester | 1991 |
| Acorn Event Safety Ltd | Newcastle Upon Tyne | 2024 |
| Acorn Furniture Hire Limited | Thatcham | 2012 |
| Acorn Health & Leisure Ltd | London | 2014 |
| Acorn Print Studio Limited | Edinburgh | 2026 |
| Acorn Sporting Ltd | Burton-On-Trent | 2022 |
| Acorn Studios Limited | Abergavenny | 2023 |
| Acorn Trails Limited | Glasgow | 2021 |
| Acorn Wellness Limited | Harrogate | 2016 |
| Acorn World CIC | Harrogate | 2024 |
| Acornrise Limited | Swansea | 2001 |
| Acorns Events Limited | Leicestershire | 2007 |
| Acorns Motorcycle Club Limited | Stafford | 2009 |
| Acosta Dance Centre Limited | Haywards Heath | 2021 |
| Acosta Dance Foundation Ltd | Haywards Heath | 2011 |
| Acouk | London | 2008 |
| Acoustic Blue (Music Productions) Limited | Hope Valley | 1990 |
| Acoustic Nations Live CIC | Lincoln | 2021 |
| Acoustic Solutions Yorkshire Limited | Ripon | 2016 |
| Acoustickle CIC | Nottingham | 2025 |
| Acoustics Unfiltered Limited | London | 2022 |
| Acoustiguide Limited | | 1977 |
| ACP Recordings Limited | London | 2007 |
| ACP Support (Aylsham) Ltd | Norwich | 2018 |
| Acpilates Ltd | Folkestone | 2024 |
| Acquah Analytics Ltd | Coventry | 2014 |
| Acquiesce Solutions Limited | Waltham Abbey | 2009 |
| Acquire Productions Ltd | Glasgow | 2026 |