| Abertillery Youth Drama & Music Society CIC | Blaina | 2021 |
| Aberystwyth & District Motor Club Limited | Talybont | 1984 |
| Aberystwyth & District Motorcycle Club | Aberystwyth | 2008 |
| Aberystwyth Musicfest Ltd | Aberystwyth | 2016 |
| Aberystwyth Rugby Football Club (2019) Limited | Aberystwyth | 2019 |
| Aberystwyth Town Football Club Ltd | Dyfed | 2000 |
| Abesongs Limited | Essex | 1975 |
| Abfabfit Club (Bishops Stortford) Limited | Bishops Stortford | 2021 |
| ABH Touring Limited | Cheltenham | 2019 |
| Abhinav Shankar Mishra Company Ltd | London | 2026 |
| Abhk Ltd | Saffron Walden | 2017 |
| ABI ANN Davis Ltd | London | 2026 |
| ABI Book Design Limited | London | 2023 |
| ABI Boxing Intensive Ltd | Woodford Green | 2019 |
| ABI Entertainment Limited | Aylesbury | 2023 |
| ABI Morris and Co Ltd | Banbury | 2024 |
| Abiah Limited | London | 2015 |
| Abid Atelier Ltd | London | 2021 |
| Abigail ANA Productions Limited | Bromsgrove | 2020 |
| Abigail Borg Ltd | Birmingham | 2011 |
| Abigail Hayes Limited | London | 2015 |
| Abigail MAY Golf Limited | St. Andrews | 2023 |
| Abigail Michaela Ltd | Cannock | 2021 |
| Abigail's Trails Ltd | Rossendale | 2020 |
| Abilities United Ltd | Aberdeen | 2025 |
| Ability Counts Adaptive Fitness CIC | Carlisle | 2026 |
| Ability Shetland Ltd | Lerwick | 2000 |
| Abingdon Abbey Buildings Trading Limited | Abingdon | 2022 |
| Abingdon Events Partnership Ltd | Faringdon | 2021 |
| Abingdon Gymnastics Club Limited | Eynsham | 2012 |
| Abingdon Studios | Blackpool | 2016 |
| Abinger Forest Riding Club Ltd | Billingshurst | 2024 |
| Abington Bowling Club Limited | | 1921 |
| Abir the Colours of Life Ltd | London | 2014 |
| ABK Gym Group Ltd | London | 2025 |
| ABL Swim Limited | Gillingham | 2018 |
| Abla Studios Ltd | Rayleigh | 2020 |
| Ablazers Performing Arts Education Limited | Hertfordshire | 2025 |
| Able 2 Adventure CIC | Nethy Bridge | 2018 |
| Able and Hale Limited | Grays | 2022 |
| Able Athletic Limited | London | 2021 |
| Able Fitness (Peterborough) Limited | Peterborough | 2022 |
| Able Music Limited | London | 2019 |
| Able Sports Management Ltd | Blackpool | 2013 |
| Able to Dance Community Interest Company | Cleadon | 2019 |
| Ableroots CIC | Risca | 2025 |
| Ablique Fitness Limited | Slough | 2022 |
| Ablo Picasso London Ltd | Harrow | 2024 |
| Ablx Ltd | Covingham | 2023 |
| ABM Keynote & Consulting Limited | Cleator Moor | 2023 |
| Abn'G World Ltd | Windsor | 2024 |
| Abney Park Trust | London | 1991 |
| Abode Wellness Ltd | Barnet | 2024 |
| Aboodoey Entertainment Ltd | Beaworthy | 2019 |
| Aborges Services Limited | Ipswich | 2025 |
| Aboucompetitions Ltd | Kington | 2026 |
| About 60 Ltd | Surbiton | 2026 |
| About Festivals Limited | Leicester | 2024 |
| About Sports UK Limited | Guildford | 2011 |
| About Time Theatre Company Limited | Surrey | 1992 |
| About US Ltd | Glasgow | 2021 |
| Above & Below Leisure Ltd | Pontefract | 2019 |
| Above & Beyond Merchandise UK Limited | Solihull | 2018 |
| Above 100 Events Ltd | Chelmsford | 2020 |
| Above ALL Images Limited | Downham Market | 2014 |
| Above and Below (UK) Limited | Ryehill | 2002 |
| Above and Beyond Touring Limited | Lewes | 2022 |
| Above Average Fitness Limited | Wrexham | 2015 |
| Above Deck Ltd | London | 2017 |
| Above Football Ltd | Hatfield | 2024 |
| Above Limits Stunt Academy Ltd | Bangor | 2021 |
| Above the Bay Ltd | Milton Keynes | 2008 |
| Above the RIM Ltd | London | 2022 |
| Above the Stag Theatre Limited | Harrow | 2023 |
| Aboxr Limited | London | 2021 |
| Aboyne Highland Games | Aberdeen | 1998 |
| Aboyne Small Bore Rifle Club Ltd | Aboyne | 2024 |
| ABP Productions Limited | London | 2018 |
| Abph Events Ltd | Rugeley | 2022 |
| ABQ72 Limited | London | 2001 |
| ABR Management Ltd | Sidmouth | 2025 |
| ABR Stage Crew Limited | Pontypridd | 2015 |
| Abraham Kritzman Studio Ltd | Hove | 2022 |
| Abraham Rifkin Foundation Ltd | Bradford | 2023 |
| Abram Community Centre Limited | Wigan | 2006 |
| Abraxas Academy Limited | King'S Lynn | 2025 |
| Abrazo Ltd | Chesham | 2023 |
| Abridge Boar Ltd | Dartford | 2021 |
| Abridge Golf & Country Club Limited | Essex | 1962 |
| Abridge Golf Club (Holdings) Limited | Essex | 2001 |
| Abrivia Ltd | Billericay | 2018 |
| Abrupt Events Ltd | Dumbarton | 2025 |
| ABS BP London Ltd | Liverpool | 2022 |
| ABS City Ltd | Liverpool | 2025 |
| ABS Entertainment Ltd | Bedford | 2021 |
| ABS Fitness Fakenham Ltd | King'S Lynn | 2022 |
| ABS Gym Fakenham Ltd | King'S Lynn | 2022 |
| ABS Gym Ltd | King'S Lynn | 2022 |
| ABS Gym Swaffham Ltd | King'S Lynn | 2025 |
| ABS Media Limited | London | 2017 |