| A.D.Antrobus & SON Electrical Contractors Ltd | Southport | 2023 |
| A.D.Antrobus Electrical Contracting Services Ltd | Southport | 2023 |
| A.D.J. Z. Real Estate Ltd | London | 2024 |
| A.E. Andrew (Developments) Limited | Plymouth | 1964 |
| A.E.A. Prowting Limited | York | 1961 |
| A.F. Shaw Precision Grinding Limited | Halesowen | 1986 |
| A.F. Townsend (Funeral Directors) Limited | Sutton Coldfield | 1982 |
| A.F. Wilkinson Limited | Bingley | 1999 |
| A.F.S. Express Limited | Solihull | 2001 |
| A.F.W. Maintenance Limited | Ballyclare | 2005 |
| A.Fleming(Southsea)Limited | Hayling Island | 1923 |
| A.G. Butler & SON Limited | Essex | 1972 |
| A.G. Standard Company Limited | Kettering | 1929 |
| A.G.M Steel Fabrication Ltd | Portsmouth | 2024 |
| A.H Baldwin & Sons Limited | London | 2025 |
| A.H. (Zimbabwe) Limited | London | 1935 |
| A.H. Direct Ltd | Tetbury | 2007 |
| A.H. Sultan Ltd | Southampton | 2024 |
| A.H.A Design Limited | Eastbourne | 2014 |
| A.Harrison(Bedding) Limited | Leeds | 2009 |
| A.Haxby & Sons (Filey) Limited | Sutton Coldfield | 1949 |
| A.I. International Laminates Limited | Chertsey | 1980 |
| A.I.D. Partnership Limited | Cannock | 2011 |
| A.I.J. Construction Limited | Lichfield | 2016 |
| A.I.O.N. (Artificial Intelligence Off-Line Network) Ltd. | London | 2026 |
| A.I.R. Team Ltd | Oldbury | 2015 |
| A.J Taylor Group Limited | Worcester | 2025 |
| A.J. Franklin & Sons Limited | Colchester | 2002 |
| A.J. Gateway (UK) Limited | London | 2006 |
| A.J. Property Investments Limited | Derby | 1999 |
| A.J. Timmins & Sons Limited | Cradley Heath, West Midlands | 2021 |
| A.J.Hollands & SON Limited | Croydon Surrey | 1949 |
| A.J.N. (Holdings) Ltd | Newmarket | 2014 |
| A.J.Qvist Ltd | London | 2023 |
| A.J.S. (Tyres) Ltd | Hertford | 2004 |
| A.K Anderson & Co Ltd | Laurencekirk | 2024 |
| A.K. Riley Limited | Brighton | 2004 |
| A.Kaberg KYL OCH Svetsservice Limited | London | 2015 |
| A.L.H. 86 Group Ltd | Dover | 2013 |
| A.M Meer Limited | Pinner | 2021 |
| A.M. Craig Limited | Milton Keynes | 1949 |
| A.M. Proos & Sons Limited | Sheffield | 1977 |
| A.M. Surgery Limited | Worsley | 2012 |
| A.M.B Auto Services Limited | Lancing | 2015 |
| A.M.B. Products Limited | Mexborough | 1959 |
| A.M.D.R. & Co. Limited | Sutton | 2022 |
| A.M.I.P Limited | Leeds | 2006 |
| A.M.S. (South East) Fabrications Limited | Wickford | 2025 |
| A.M.S. Imports Exports Limited | London | 1996 |
| A.N.A. Ferrum (UK) Ltd | London | 2012 |
| A.N.G Analysis Limited | Dunfermline | 2015 |
| A.N.M. Powell Engineering Limited | Greater Manchester | 2007 |
| A.P. Screen Printers Limited | London | 1980 |
| A.P.A. (Kirby Muxloe) Limited | Blackburn | 2025 |
| A.R Adam Group Ltd | London | 2019 |
| A.R Studholme Maintenance Ltd | Peterborough | 2024 |
| A.R. Hendricks Limited | Llangefni | 1987 |
| A.R.D Group Holdings Ltd | Feltham | 2022 |
| A.S Cooling Ltd | Orpington | 2026 |
| A.S S.H Stadservice Limited | London | 2022 |
| A.S. Audhali (Broiler Farms) Limited | Warwick | 1982 |
| A.S. Kitching Limited | Telford | 1947 |
| A.S.Kalsi & Co. Limited | Birmingham | 2004 |
| A.S.P. Properties Limited | | 1982 |
| A.Steede & Co. Limited | Belfast | 1971 |
| A.T. Finn Consulting Ltd | Altrincham | 2014 |
| A.T. Genders Limited | Sutton Coldfield | 1982 |
| A.T. Short Installations Limited | Sutton | 2013 |
| A.T.B. Holdings Limited | Stourbridge | 2016 |
| A.T.Chown & Co.Limited | Bagshot | 1952 |
| A.T.F.P. Limited | Chippenham | 2010 |
| A.U.D Trading Limited | Luton | 2024 |
| A.V. Taylor Holdings Limited | Newcastle Upon Tyne | 2024 |
| A.V.Band Limited | Sutton Coldfield | 1958 |
| A.W Beauty Ltd | Slough | 2022 |
| A.W. Ennis (N.I.) Limited | Lisburn | 1995 |
| A.W. Fenn & Co Limited | Stanford-Le-Hope | 2014 |
| A.W. Freeman Limited | Southampton | 1957 |
| A.W. Lumb (Midlands) Limited | London | 1976 |
| A.W. Lumb (Northern) Limited | London | 1980 |
| A.W. Smith & Sons (Sundries) Limited | Birmingham | 1984 |
| A.W.L. Holdings Limited | Ramsgate | 1999 |
| A.W.Wills and Son,Limited | Willenhall | 1912 |
| A/O Credit Control Ltd | London | 2010 |
| A1 Accident Management Limited | Enfield | 2003 |
| A1 Ace Bates Skip Hire Limited | Belfast | 1997 |
| A1 Aerials Limited | Solihull | 2012 |
| A1 Auto Group Limited | Enfield | 2003 |
| A1 Bates Bros. Skip Hire Limited | Belfast | 1997 |
| A1 Batesy Skip Hire Limited | Belfast | 1997 |
| A1 Bathrooms Limited | Basingstoke | 2013 |
| A1 Building Supplies & Maintenance Limited | Wokingham | 2013 |
| A1 Gospel Ltd | Wrexham | 2013 |
| A1 Gospel TV Ltd | Wrexham | 2013 |
| A1 Hire (UK) Limited | Enfield | 2003 |
| A1 Hire and Sales Limited | Bournemouth | 2025 |
| A1 Kitchens Limited | Basingstoke | 2015 |
| A1 Lifts Limited | Kingswinford | 2026 |
| A1 Ltd | Cambridge | 2021 |
| A1 Mechanical Maintenance Limited | Hatfield | 2010 |