| A World in Miniature Limited | Thornhill | 2002 |
| A Wright Mechanical Ltd | Warrington | 2025 |
| A&A Forwarding Limited | Felixstowe | 2012 |
| A&A Investment Management Ltd | Edinburgh | 2011 |
| A&A Sable Limited | London | 2019 |
| A&A's Sons Ltd | Gravesend | 2022 |
| A&C Manufacturing Limited | Chorley | 2012 |
| A&E Medical Limited | Northampton | 2007 |
| A&F Dog Services Limited | Grays | 2022 |
| A&H Maintenance Ltd | Braintree | 2023 |
| A&J Coles Ltd | Northampton | 2010 |
| A&J Consultancy Ltd | York | 2002 |
| A&K Titley Limited | Fairbourne | 2015 |
| A&L Bespoke Design Ltd | Aylesbury | 2024 |
| A&M (Donnington) Parts Limited | Reading | 2019 |
| A&M Cleaning Solution Ltd | Guildford | 2024 |
| A&M Coastal Property Maintenance Ltd | St. Austell | 2024 |
| A&M Pensions Ltd | Dartford | 2012 |
| A&M Team Ltd. | Bromley | 2015 |
| A&N Suites Limited | London | 2024 |
| A&P Business Services Ltd | Gillingham | 2025 |
| A&S Cole Investments Limited | Exeter | 2016 |
| A&T Office Admin Solutions Ltd | Leeds | 2020 |
| A&U Investments Ltd | Cardiff | 2020 |
| A&V Building Solution Ltd | Holborn | 2017 |
| A&Y Electrical Solutions Ltd | Sheffield | 2022 |
| A'Shore Thing Ltd | London | 2025 |
| A,C,E's Boutique Ltd | Hengoed | 2024 |
| A-App Investment Limited | London | 2025 |
| A-B Hestetransport Invest Limited | London | 2025 |
| A-B Hestetransport Limited | London | 2025 |
| A-B Investment Sweden Limited | London | 2025 |
| A-B Sweden Limited | London | 2025 |
| A-Core Services Ltd | London | 2008 |
| A-Fab Welding & Fabrication Limited | Fordingbridge | 2018 |
| A-Fix Plumbing Ltd | Swansea | 2019 |
| A-Gas Limited | Bristol | 1993 |
| A-Ihome Furniture Ltd | Beckenham | 2018 |
| A-Niche Limited | Manchester | 2024 |
| A-Plus Enterprise Co., Ltd | Cardiff | 2016 |
| A-Red Machinery International Co., Ltd | Cambridge | 2018 |
| A-Side Official Limited | Basingstoke | 2023 |
| A-Tech Academy Ltd | Newton Aycliffe | 2012 |
| A-Tech Battery Handling Solutions Limited | Newton Aycliffe | 2013 |
| A-Tech Electronics Limited | Newton Aycliffe | 2013 |
| A-Trade Solutions Ltd | Loughton | 2020 |
| A-Z Plus Building Surveyors Limited | Southport | 2019 |
| A-Z Snekker Limited | London | 2022 |
| A. & a. King Limited | Wimborne | 1989 |
| A. & B. Securities Limited | | 1940 |
| A. & D. Billiards & Pool Services Limited | Liverpool | 1978 |
| A. & E.G. Heading (Thorney) Limited | Bury St Edmunds | 1953 |
| A. B. Plant Shipping (NL) Ltd | Portsmouth | 2017 |
| A. Bagley Hospitality Ltd | Isle Of Lewis | 2019 |
| A. Bates Skip Hire Limited | Belfast | 1996 |
| A. Baveystock & Co., Limited | London | 1980 |
| A. Brooks Ltd | Poulton Le Fylde | 2016 |
| A. Buckler Demolition Limited | Middlesborough | 2003 |
| A. C. Rigging Limited | High Wycombe | 2008 |
| A. C. Video Limited | High Wycombe | 2008 |
| A. E. Parker Ltd | Chichester | 2021 |
| A. Hazel & Sons Limited | Sutton Coldfield | 1972 |
| A. J. Plastics Limited | Walsall | 1977 |
| A. J. R. Lynch and Company Limited | Wakefield | 2015 |
| A. Jophiel Ltd | West Kirby | 2005 |
| A. K. Locksmiths Ltd | London | 2004 |
| A. K. Worthington Ltd | Manchester | 2014 |
| A. M. Management Accounting Ltd | Wokingham | 2025 |
| A. Norris Electrical Limited | Eastleigh | 2005 |
| A. Pank & SON Limited | Norwich | 2006 |
| A. Pollick Employee Trustee Limited | Merseyside | 2021 |
| A. S. D. WH Holdings Limited | Sutton-In-Ashfield | 2016 |
| A. Shepherd & Sons Limited | Sutton Coldfield | 1983 |
| A. Sjonell Invest Limited | London | 2018 |
| A. Steadman & SON (Holdings) Limited | Sheffield | 2006 |
| A. Steadman & SON Limited | Sheffield | 1987 |
| A. Sulka and Company Limited | | 1924 |
| A.A Consultation Limited | Holywood | 2015 |
| A.A. Pensions Trustees Limited | Basingstoke | 2013 |
| A.A.E.S. (Ireland) Ltd | Craigavon | 2019 |
| A.And N.Duckworth Limited | Sutton Coldfield | 1963 |
| A.Ashton and Sons Limited | Sutton Coldfield | 1953 |
| A.B. Controls and Technology Limited | Doncaster | 2006 |
| A.B.C. Bearings Limited | Peterborough | 1987 |
| A.B.M. Engineering Services Limited | Widnes | 2024 |
| A.Bennett & Sons Limited | Sutton Coldfield | 1928 |
| A.C. Airconditioning Limited | Wotton-Under-Edge | 1982 |
| A.C. Audio Limited | High Wycombe | 2007 |
| A.C. Leigh Ltd | Norwich | 2013 |
| A.C. Lighting (Holdings) Limited | High Wycombe | 2019 |
| A.C. Lighting Limited | High Wycombe | 2008 |
| A.C. Mole & Sons Limited | Taunton | 2005 |
| A.C. Roof Trusses Limited | Llangefni | 2003 |
| A.C.C. Freight Management Limited | Witham | 2021 |
| A.C.Flooring Ltd. | Knowlhill | 1995 |
| A.C.L. Limited | | 1962 |
| A.C.S Catering Limited | Banbury | 2015 |
| A.D Communications (Fife) Ltd | Dunfermline | 2019 |
| A.D. Textile Co., Ltd | Beckenham | 2014 |
| A.D.A.M. Investments Limited | Chard | 1979 |