| A.E.Chambers Limited | Nottingham | 1962 |
| A.E.Chapman & Co.,(Old Hill)Limited | Cradley Heath | 1942 |
| A.E.Clegg Limited | Worcester | 1956 |
| A.E.Direct CYF | Wrexham | 2019 |
| A.E.Harris & Company(Birmingham)Limited | West Bromwich | 1929 |
| A.E.M. Products Limited | Rushden | 1995 |
| A.E.N.J. Limited | East Grinstead | 2012 |
| A.E.P. (Steel Fabrications) Limited | Salisbury | 1988 |
| A.E.P. UK Limited | Northampton | 2004 |
| A.E.R. Stafford Limited | Bristol | 2009 |
| A.E.S. (Birmingham) Limited | Birmingham | 1986 |
| A.E.S. Engineering Limited | Mill Close Rotherham | 1945 |
| A.E.S. Industries Limited | Grimsby | 2000 |
| A.E.Simmons Limited | Chelmsford | 1946 |
| A.E.T. Engineering Limited | Normanton | 1974 |
| A.E.T. Extraction Limited | Newport | 2005 |
| A.E.V. Limited | Birkenhead | 1982 |
| A.Edmonds & Co.Limited | | 1914 |
| A.F. (Fife) Ltd | Leven | 2025 |
| A.F. Drabble Engineers Limited | Blackpool | 2005 |
| A.F. Kitchens Ltd | Oldham | 2013 |
| A.F. Maintenance Limited | Okehampton | 2008 |
| A.F. Original Limited | Chelmsford | 2019 |
| A.F. Plant & Engineering Services Ltd | Cheltenham | 2017 |
| A.F.A.C. Limited | Nuneaton | 2000 |
| A.F.Hussey(London)Limited | Harlow | 1963 |
| A.F.I.P. Commercial Ltd | Colchester | 2017 |
| A.F.K. (Marketing) Limited | Lincolnshire | 1991 |
| A.F.L. Trucks Limited | Haverhill | 1988 |
| A.F.S. Services Limited | Tamworth | 2002 |
| A.F.T. (UK) Limited | Retford | 1985 |
| A.F.T. Trenchers Limited | Sudbury | 2001 |
| A.F.White Limited | Birmingham | 1963 |
| A.Farah Services Limited | Feltham | 2006 |
| A.Fisher Electrical Services Limited | Bakewell | 2021 |
| A.G. Barr P.L.C. | Cumbernauld | 1904 |
| A.G. Carpenter Ltd | Gravesend | 2025 |
| A.G. Engineering Welding & Fabrication Services Limited | Chelmsford | 2014 |
| A.G. Fabrications Limited | Rayleigh | 1995 |
| A.G. Mcgill Limited | Wallington | 1990 |
| A.G. Production Machines Limited | York | 1978 |
| A.G. Westmoreland & Co. Limited | Llanfairfechan | 1922 |
| A.G.A. Profilers Limited | Sheffield | 2009 |
| A.G.A.Joinery Ltd | London | 2016 |
| A.G.C Fashion Ltd | London | 2018 |
| A.G.C.Engineering Company Limited | Ruislip | 1963 |
| A.G.E Group Ltd | Sunderland | 2023 |
| A.G.E. Beauty Services Ltd | Tring | 2022 |
| A.G.Hackney and Company Limited | Burslem | 1938 |
| A.G.M. Services Limited | Haslingden | 1993 |
| A.G.W. Electronics Limited | Ditchling | 1974 |
| A.H Beds Ltd | Dewsbury | 2024 |
| A.H Joinery & Kitchens Ltd | Halstead | 2020 |
| A.H Painting & Decorating MCR Ltd | Manchester | 2021 |
| A.H. Engineering Support Services Ltd | Walsall | 2017 |
| A.H. Mead & SON (Engineering) Limited | Dunmow | 1989 |
| A.H.Carpenter Ltd | Staines-Upon-Thames | 2021 |
| A.H.Dodd & Company(Engineers)Limited | Chippenham | 1954 |
| A.H.Garner Limited | Nottingham | 1949 |
| A.H.Tomlinson Parbans Limited | Stockport | 1956 |
| A.Hollur & Sons Ltd | London | 2018 |
| A.I Engineering Ltd | Dumfries | 2010 |
| A.I Fabrications Ltd | Nottingham | 2024 |
| A.I.A. Shot Blasting Ltd | Boston | 2019 |
| A.I.E. Services Limited | Burgess Hill | 2005 |
| A.I.M(Uk) Ltd | Sutton Coldfield | 2016 |
| A.I.O.W. Limited | Newport | 2011 |
| A.I.P. Compressor Services Limited | Ossett | 1981 |
| A.I.R. Cladding Supplies Limited | Stone | 2011 |
| A.I.S. Tectonic Limited | | 1965 |
| A.I.S.Sheet Metal Limited | Kidderminster | 1971 |
| A.Instincts Limited | London | 2016 |
| A.Iyala Ltd | London | 2023 |
| A.J. Armstrong & Sons Ltd | Maghera | 2011 |
| A.J. Baker (Grinding) Limited | Aldridge,Walsall | 1976 |
| A.J. Binns Limited | Potters Bar | 1937 |
| A.J. COE Limited | Brightlingsea | 2004 |
| A.J. Cope & SON Limited | West Thurrock | 1958 |
| A.J. DEW Ltd | Cambridge | 2024 |
| A.J. George Refrigeration and Air Conditioning Limited | Bristol | 1990 |
| A.J. Hornig Limited | Dunfermline | 1972 |
| A.J. Johnson Limited | Workington | 2003 |
| A.J. Martin Ventilation Services Limited | Fleet | 2000 |
| A.J. Metal Fabrications Limited | London | 1987 |
| A.J. Metal Products Limited | Brierly Hill | 1984 |
| A.J. Metal Work Ltd | Tilbury | 2012 |
| A.J. Pies and Pastries Limited | Huddersfield | 2011 |
| A.J. Power (GB) Limited | Peterborough | 2022 |
| A.J. Power Limited | Craigavon | 2003 |
| A.J. Sharp Limited | Sheffield | 1999 |
| A.J. Signs Limited | Guildford | 1984 |
| A.J. Tassi Limited | Ilkeston | 2005 |
| A.J. Tebbutt Joinery Limited | Rochester | 1997 |
| A.J. Wells & Sons Limited | Isle Of Wight | 1999 |
| A.J. Wintergreen Limited | Ashford | 2019 |
| A.J.Automatic Machine Co.Ltd | Weston-Super-Mare | 2003 |
| A.J.B. Woodworking Limited | Leicester | 1999 |
| A.J.Brett & Co.Limited | London | 1952 |
| A.J.C Retail UK Ltd | London | 2026 |
| A.J.C. Trailers Limited | Colindale | 1974 |