| AAT Grounds Services Ltd | Plymouth | 2015 |
| AB Agri Drones Ltd | Whitby | 2025 |
| AB Agro Ltd | Maidenhead | 2025 |
| AB Engineering & Agri Ltd | London | 2023 |
| AB Farms Ltd | London | 2015 |
| AB Fisheries Ltd | Bristol | 2025 |
| AB Heating Ltd. | Peterhead | 2004 |
| AB Initio Limited | Salisbury | 1997 |
| AB Marine Consultancy Ltd | Paignton | 2021 |
| AB Obice Saevior Ltd | Hawick | 2020 |
| AB Sport Horses Limited | Lancashire | 2006 |
| AB Systems (UK) Limited | Okehampton | 2011 |
| Ab's Combined Services Ltd | Paignton | 2010 |
| AB56 Limited | Edinburgh | 2019 |
| AB9 Ltd | Launceston | 2021 |
| ABA Investments Limited | Peterborough | 2015 |
| Abacus Agriculture Limited | Guildford | 2014 |
| Abalayden Fishing Ltd | Peterhead | 2023 |
| Abather Limited | Tenterden | 2004 |
| ABB Forum Ltd | Bromley | 2025 |
| Abba Tree Specialist Ltd | Aberystwyth | 2018 |
| Abbey BIO Fibre Products Limited | Cookstown | 2020 |
| Abbey Eggs Limited | Llandrindod Wells | 2015 |
| Abbey Farm Equestrian Ltd | Spondon | 2019 |
| Abbey Farm Feeds Limited | Fareham | 2017 |
| Abbey Farmers Limited | Worcester | 1981 |
| Abbey Farming Limited | Lincoln | 1999 |
| Abbey Foods Limited | Cannock | 2015 |
| Abbey Garth Farm Limited | Hull | 2025 |
| Abbey Garth Pigs Limited | Hull | 2004 |
| Abbey Horse Racing and Breeding Limited | | 2004 |
| Abbey House Environmental Limited | Stapleford Nottingham | 2016 |
| Abbey Tree Company Limited | Ilkeston | 2019 |
| Abbey View Produce Limited | Waltham Abbey | 1972 |
| Abbeyheath Limited | Pirbright | 1996 |
| Abbeystead Partners Ltd | Wirral | 2023 |
| Abbiss Farming Limited | Bridgnorth | 2025 |
| Abbot's Court Farm(Charborough) | Bournemouth | 1967 |
| Abbots Ripton Farming Company Limited | Huntingdon | 1959 |
| Abbotshall Evanton Limited | Ross-Shire | 1965 |
| Abbotsley Farms Limited | St Neots | 2008 |
| Abbotts Farm (East Hagbourne) Ltd | Didcot | 2017 |
| Abby Links Ltd | Felixstowe | 2023 |
| ABC Christmas Tree Limited | London | 2018 |
| ABC Marine Burra Ltd | Burra | 2019 |
| ABC Treecare Limited | Carlisle | 2023 |
| Abcd Farms Limited | Beragh | 2014 |
| Abcd Rail Limited | Launceston | 2022 |
| Abctree Limited | Cambridge | 2017 |
| Abdaal Ltd | Barking | 2025 |
| Abdalla Elkhodary for Trading and Supplies Ltd | London | 2025 |
| Abel Farms Ltd | Ripon | 2012 |
| Abell Perennial Plants Limited | Devon | 2006 |
| Aber Falls Kennels Limited | St Asaph | 2014 |
| Aberarder Estate Limited | Bristol | 2023 |
| Aberbothrie Potatoes Ltd. | | 1994 |
| Aberdata Limited | Shaftesbury | 1986 |
| Aberdeen Fish Producers' Organisation, Limited | Aberdeen | 1973 |
| Aberdeenshire Christmas Tree Adoption Ltd | Peterhead | 2024 |
| Aberdeenshire Farm Contracting Limited | Aberdeen | 2018 |
| Aberdeenshire Highland Cattle Limited | Banchory | 2015 |
| Abergairn Limited | Edinburgh | 2024 |
| Abergavenny Area Community Orchards and Gardens CIC | Abergavenny | 2011 |
| Abergavenny Vineyards Ltd | Abergavenny | 2022 |
| Abergwenllan Limited | Caldicot | 2016 |
| Abergwynant Estate Ltd. | Snowdonia | 1979 |
| Aberhall Limited | Hereford | 2022 |
| Abersoch Moorings Limited | Pwllheli | 2005 |
| Abertawe & Gower Tree Surgery (2011) Ltd | Swansea | 2011 |
| Aberuchill Management Limited | Leith | 2005 |
| Aberystwyth Angling Association Limited(The) | Aberystwyth | 1929 |
| Aberystwyth Innovation and Enterprise Campus Limited | Aberystwyth | 2014 |
| Abhirama Ltd | Leicester | 2025 |
| Abhirati Plants and Pots Ltd | Chester | 2025 |
| ABI Flynn Equestrian Services Ltd | Southampton | 2023 |
| Abide International Ltd | London | 2024 |
| Abijax Labradors Ltd | Stourbridge | 2021 |
| Abinesfarm Limited | Nr Thirsk | 1962 |
| Abington Farms Limited | Cambridgeshire | 1948 |
| Abireo Animal Nutrition Ltd | Ballynahinch | 2025 |
| Abiseal Ltd | Sutherland | 2025 |
| ABJ Straw Tendring Limited | Colchester | 2024 |
| Abla Arabians Ltd | Perth | 2016 |
| Able Assist Dogs UK Ltd | Sheffield | 2022 |
| Able Tree Services Ltd | Hexham | 2025 |
| Able Tree Surgeons Ltd | Holmfirth | 2018 |
| ABM Farms Limited | Bishop Auckland | 2005 |
| Abmor Fishery Ltd | Glasgow | 2020 |
| Abnoba Farm and Equine Ltd | Derby | 2026 |
| Abolengo Propco Ltd | Corwen | 2024 |
| Abolhassani Company Limited | London | 2025 |
| About Trees Ltd | Whitstable | 2014 |
| Above & Beyond Tree Services Ltd | Benfleet | 2022 |
| Above and Beyond Pet Care Ltd | Snodland | 2025 |
| Abpro Ltd | Wallasey | 2022 |
| Abrahams Equestrian Ltd | Chesterfield | 2019 |
| Abrams Farm Livery & Stud Ltd | Simonswood | 2024 |
| Abriachan Forest Trust | | 1997 |
| Abrimar Limited | Edinburgh | 2020 |
| Abrinvest Limited | Corby | 2012 |