| A.Algeo Limited | Liverpool | 1947 |
| A.B Aircon Ltd | Liverpool | 2022 |
| A.B Cooling Solutions Ltd | Liverpool | 2025 |
| A.B. Clothing Limited | Leicester | 1990 |
| A.B. Conveyors Ltd | Ollerton | 2015 |
| A.B. Engineering (Laurencekirk) Ltd. | | 2004 |
| A.B. FAN Services Limited | Dudley | 2004 |
| A.B. Group Packaging UK Limited | Bolton | 2010 |
| A.B. Hoses & Fittings Limited | Storforth Lane | 1987 |
| A.B. Screenprint Limited | | 1996 |
| A.B. Sealants Limited | Blackburn | 2011 |
| A.B. Terratec Limited | Halifax | 1983 |
| A.B.C. (Enamelling & Fabrications) Limited | High Street | 1976 |
| A.B.C. (Stainless) Limited | Peterborough | 1980 |
| A.B.C. - Top Mixer Hire Limited | Warrington | 2006 |
| A.B.C. Glass Processing Limited | Portsmouth | 1999 |
| A.B.C. Pressings Limited | Bath Road | 1980 |
| A.B.C.>Concrete Direct Limited | Warrington | 2013 |
| A.B.G. Limited | Holmfirth | 1988 |
| A.B.G. Rubber & Plastics Limited | Leicester | 1975 |
| A.B.I. Electronics Limited | Barnsley | 1984 |
| A.B.M.Precisions(Nuneaton)Limited | Claybrooke Parva | 1964 |
| A.B.R. (Specialist Welding) Limited | West Midlands | 1984 |
| A.B.R. Fabrications Limited | Manchester | 1997 |
| A.B.T. Design Limited | Dartford | 1986 |
| A.B.T.Products Limited | Ross-On-Wye | 1971 |
| A.B.Y. Knitting Co. Limited | Elland | 2010 |
| A.Barr T/A Alpha Business Machines Limited | Edinburgh | 2013 |
| A.Becker Ltd | Grimsby | 2023 |
| A.Birtles Consultancy Ltd | Manchester | 2012 |
| A.Boddington Limited | Derby | 2019 |
| A.Butler & Sons Limited | London | 1917 |
| A.C. Access Limited | Fraserburgh | 2011 |
| A.C. Contract Interiors Limited | Bridgend | 2011 |
| A.C. Electrical (Suffolk) Limited | Stowmarket | 2018 |
| A.C. Engineering (North East) Limited | Bedlington | 1999 |
| A.C. Hydraulics Limited | Leicester | 1977 |
| A.C. Independent Services Limited | Stockton-On-Tees | 2010 |
| A.C. Print Ltd | Paignton | 2003 |
| A.C. Sheetmetal Limited | Uckfield | 2004 |
| A.C. Shropshire Limited | Whetstone | 2020 |
| A.C. Technology Ltd | Bolton | 2014 |
| A.C. Tonks (Orthopaedics) Limited | Worcestershire | 1974 |
| A.C.Bacon Engineering Limited | Norwich | 1961 |
| A.C.Buckoke & Sons Limited | London | 1972 |
| A.C.D. Plant Limited | Hinckley | 1977 |
| A.C.E Carpentry & Construction Ltd | Bridgend | 2019 |
| A.C.E. Ceiling Products Limited | Arley | 1978 |
| A.C.E. Metalworks Limited | Hertford | 2002 |
| A.C.I. Engineering Limited | Hythe | 2000 |
| A.C.K. Materials Handling Limited | Birmingham | 1991 |
| A.C.O. Packaging Limited | Bishop'S Stortford | 1970 |
| A.C.P. (Concrete) Limited | Wigton | 1988 |
| A.C.P. Services Limited | Eccleshall | 1981 |
| A.C.S Group North Ltd | Glasgow | 2017 |
| A.C.S. Electrics (Midlands) Limited | Walsall | 2019 |
| A.C.S. Industries Limited | Billinghurst | 1981 |
| A.C.T. Electrical Ltd | Beauly | 2012 |
| A.C.T. Reprographics Limited | Parkway, Cardiff | 1994 |
| A.C.T. Stainless Steel Limited | Newry | 2017 |
| A.Carmichael Ltd | Blaydon-On-Tyne | 2016 |
| A.Coletta & Sons Limited | Halifax | 1959 |
| A.D. Baker (Shopfitters) Limited | Hampton | 1976 |
| A.D. Canning Joinery Ltd | Londonderry | 2011 |
| A.D. Certified Lifting Services Limited | Rugeley | 1980 |
| A.D. Co Services Limited | St. Leonards-On-Sea | 1999 |
| A.D. Composite Services Ltd | Nottingham | 2025 |
| A.D. Engineering (Kent) Limited | Sittingbourne | 2005 |
| A.D. Goddard Ltd. | Sunderland | 2012 |
| A.D. Lifts WM Ltd | Wednesbury | 2021 |
| A.D. Metal Spinners Limited | Bournemouth | 1973 |
| A.D. Recycling Solutions Limited | Sutton Coldfield | 2003 |
| A.D. Stutterheim Limited | Leicester | 2020 |
| A.D. Systems (UK) Ltd | Blackpool | 2008 |
| A.D.A. Fastfix Limited | High Wycombe | 2002 |
| A.D.A. Re-Upholstery Services Limited | Mansfield, | 1973 |
| A.D.C. Halford & Company Limited | Chester Le Street | 1998 |
| A.D.D. Filtration Ltd | Christchurch | 2010 |
| A.D.Hall Limited | Stoke On Trent | 1958 |
| A.D.P. (Aluminium Systems) Limited | Rugeley | 1987 |
| A.D.R. Engineering Limited | Uxbridge Middlesex | 1992 |
| A.D.S. Digital Print Solutions Limited | Wirral | 2008 |
| A.D.S. Graphics Limited | Park Bromborough | 1988 |
| A.D.Taylor (Joiner) Limited | Oldham | 2012 |
| A.D.X Precision Engineering Limited | Waterlooville | 1999 |
| A.E Dental Laboratory Ltd | Barry | 2026 |
| A.E. Batchelor & SON (Epping) Limited | Essex | 1946 |
| A.E. Callard (Engineering) Limited | London | 1981 |
| A.E. Davidson & SON Limited | Rotherwas | 1976 |
| A.E. George Commercials Limited | Bruton | 2012 |
| A.E. Holland Memorials Ltd | Prescot | 2017 |
| A.E. Rodda & SON Limited | Redruth | 1999 |
| A.E. Services & Supplies (International) Limited | Keighley | 2021 |
| A.E. Services and Supplies (Keighley) Limited | Crosshills | 1982 |
| A.E. Sutton Limited | Betchworth | 1962 |
| A.E. Taylor & Co. (Sunderland) Limited | | 1960 |
| A.E. Westwood Limited | Kinwarton, Alcester, | 1928 |
| A.E.Adams(Henfield)Limited | Lancing | 1965 |
| A.E.Barrow & Sons,Limited | Kent | 1934 |
| A.E.C. Limited | Milton Keynes | 2022 |