| AAO Web & AI Solutions Ltd | Cambridge | 2025 |
| Aaok Limited | Glasgow | 2023 |
| Aapex Wealth Management Ltd | London | 2017 |
| Aapoldham Limited | Oldham | 2018 |
| AAR Housing Ltd | Luton | 2024 |
| AAR Security Group Ltd | Birmingham | 2022 |
| Aardman Chicken Run Limited | Bristol | 1997 |
| Aardman Creature Comforts USA Limited | Bristol | 2000 |
| Aardman Equipment Limited | Avon | 2000 |
| Aardman Tortoise and the Hare Limited | Avon | 1996 |
| Aardman Trustees Limited | | 1998 |
| Aardtech Limited | Taunton | 2020 |
| Aardvarc Electrical Engineering Ltd | Richmond | 2013 |
| Aardvark Communications Ltd | Sleaford | 2011 |
| Aardvark Concrete Limited | Manchester | 2010 |
| Aardvark International Transport Limited | Reading | 2016 |
| Aaren Ltd | Wembley | 2024 |
| Aarhys Ltd | South Ruislip | 2021 |
| Aarix Limited | Upton-Upon-Severn | 2017 |
| Aarmor Ltd | Elstree | 2026 |
| Aaron & ASH Ltd | Coventry | 2022 |
| Aaron Black Funeral Directors Limited | Nottingham | 2007 |
| Aaron Bott Ltd | Sheffield | 2020 |
| Aaron Clarke Accountants Limited | Ipswich | 2015 |
| Aaron Clarke Ltd | Hadleigh | 2016 |
| Aaron Cleaning Services Ltd | Ely | 2025 |
| Aaron Dale Roger Dreikluft Limited | Lincoln | 2024 |
| Aaron Developments (Wrexham) Limited | Rochdale | 2005 |
| Aaron Fiyifoluwa Chimsome Odebunmi Limited | Croydon | 2024 |
| Aaron Hall Limited | Whitstable | 2019 |
| Aaron Howe Consultancy Ltd | Farnborough | 2023 |
| Aaron J Buckley INK Ltd | Rochdale | 2025 |
| Aaron Roofing Supplies Limited | Sheffield | 1996 |
| Aaron Samuel Brooking Ltd | Nottingham | 2023 |
| Aaron Services Ltd | Great Yarmouth | 2025 |
| Aaronite Partners Limited | Chelmsford | 2011 |
| Aaryana Limited | Uxbridge | 2022 |
| Aash Consultants Limited | Glasgow | 2024 |
| Aasha Caterers Limited | Wimbledon | 2010 |
| Aashvi Limited | Slough | 2022 |
| Aasmundstad Import Invest Limited | London | 2022 |
| Aasmundstad Import Limited | London | 2022 |
| AAT Electrical Ltd | Manchester | 2023 |
| AAW Group Ltd | Market Harborough | 2020 |
| AAW Holdings Limited | London | 2016 |
| AAZ Holdings Limited | Mexborough | 2021 |
| Aazaac Social and Therapeutic Work Ltd | Leicester | 2022 |
| Aazure Group Limited | London | 2018 |
| AB Bensham Ltd | Surrey | 2021 |
| AB Bonding Company Limited | Pocklington, York | 1991 |
| AB Business Link Ltd | London | 2016 |
| AB Colourful Heart Creations Limited | London | 2019 |
| AB Concept Limited | London | 2022 |
| AB Electrical & Security Co Limited | St Leonards On Sea | 2012 |
| AB Film Productions Ltd | London | 2019 |
| AB Footpaths Limited | Markfield | 2018 |
| AB Impex Ltd | High Wycombe | 2017 |
| AB Inbev Corporate Services Limited | London | 2013 |
| AB Inbev Horizon Limited | London | 2009 |
| AB Inbev Ireland Limited | Belfast | 1951 |
| AB Keepers Ltd | Colchester | 2020 |
| AB Leisure Services Limited | Treorchy | 1999 |
| AB Music Limited | London | 2016 |
| AB Nautica Limited | Blackpool | 2022 |
| AB Sales Norway Limited | London | 2019 |
| AB Vehicle Transport Limited | Southwold | 2022 |
| AB Worldwide Limited | London | 2019 |
| AB1 Nantwich Limited | Nantwich | 2020 |
| AB2 Nantwich Limited | Nantwich | 2020 |
| ABA Industrial Supplies Limited | Nottingham | 2025 |
| ABA Multiservices Ltd | London | 2009 |
| Ababa Consulting Limited | London | 2021 |
| Ababy Co., Ltd | London | 2024 |
| Abac (NI) Ltd | Omagh | 2008 |
| Abaco Taxis Ltd | Edinburgh | 2011 |
| Abacus Accountants and Business Advisors Limited | Romford | 2010 |
| Abacus Accounts (Thames Valley) Ltd | Swindon | 2020 |
| Abacus Bookkeeping Solutions Limited | Hamilton | 2016 |
| Abacus Direct Holdings Limited | Newbury | 2019 |
| Abacus Direct Limited | Newbury | 2001 |
| Abacus Elevators Limited | Kingswinford | 2026 |
| Abacus Group (Topco) Limited | Newbury | 2024 |
| Abacus Homecare (Bromley) Limited | Bromley | 2010 |
| Abacus Internet Ltd | Essex | 1996 |
| Abacus Jockey Ltd | Nottingham | 1997 |
| Abacus Land ASP 1 Limited | London | 2022 |
| Abacus Land ASP 2 Limited | London | 2022 |
| Abacus Master Locksmiths Limited | Colchester | 2004 |
| Abacus Rail Limited | Wolverhampton | 2009 |
| Abacus Refresh Ltd | Northampton | 2022 |
| Abacus Stocker Valuers Limited | Ilford | 2014 |
| Abacus Therapeutics Ltd | Bristol | 2026 |
| Abacus Trading Co. Limited | London | 2016 |
| Abakazakura Limited | Ryde | 2011 |
| Abakus Limited | Market Harborough | 2010 |
| Abanico Salsa Ltd | Torquay | 2007 |
| Abaq AL Muttahida Ltd | Doncaster | 2026 |
| Abarah Ltd | Wirral | 2016 |
| Abarth Racing UK Limited | Bletchley | 2012 |
| Abastra Asbestos Removal Service Ltd | Chadwell Heath | 2018 |