| A.S.Padda Ltd | Ashford | 2025 |
| A.S.Pickering Limited | Yorkshire | 1970 |
| A.Sagaaf Recycling and Resources Ltd | Birmingham | 2026 |
| A.Smith & Co. Heating & Plumbing Ltd | Leicester | 2026 |
| A.Smith Joinery Ltd | Liverpool | 2023 |
| A.T Builders Limited | Macclesfield | 2017 |
| A.T Commercials Co., Ltd | Chislehurst | 2017 |
| A.T Healthcare(Uk) Ltd | London | 2016 |
| A.T Shehab Ltd | London | 2025 |
| A.T. Best Handlers Limited | Airdrie | 1997 |
| A.T. Blinds Services Ltd | Kent | 2001 |
| A.T. Cronin Workshop Limited | London | 2017 |
| A.T. Cross (Europe), Ltd. | Stratford-Upon-Avon | 1994 |
| A.T. Juniper (Liverpool) Limited | Prenton | 1978 |
| A.T. Osborne Limited | Ower | 1975 |
| A.T. Refractories Limited | Cheadle, Stoke On Trent | 2002 |
| A.T. Speedometer Company Limited | Ystrad Meurig | 2014 |
| A.T.B. Plastics Limited | Chelmsford | 1987 |
| A.T.B. Systems Limited | Stourbridge | 1994 |
| A.T.Brown & Co,Limited | Rainham | 1945 |
| A.T.C. Colours Limited | Cheadle | 1989 |
| A.T.C. Trading Limited | London | 1969 |
| A.T.E. Solutions Limited | Northampton | 2002 |
| A.T.F. (Textiles) Limited | Blackburn | 2005 |
| A.T.H. (Hydraulics) Limited | Blakeney | 2001 |
| A.T.L. Agricultural Technology Limited | Newmarket | 1980 |
| A.T.O.M. Limited | Ascot | 1984 |
| A.T.P. Instrumentation Ltd. | Kettering | 1990 |
| A.T.P.Electronic Developments Limited | Cannock | 1986 |
| A.T.S.I. Limited | Pinner | 2000 |
| A.T.Siddons & Sons Limited | Leicester | 1955 |
| A.Taylor Agri Ltd | Kingswinford | 2026 |
| A.Ti Marine Limited | Bournemouth | 2022 |
| A.U Moulding Limited | Erith | 2026 |
| A.V. Birch Limited | Acton Round Bridgnorth | 2003 |
| A.V. Engineering Services Limited | Royston | 1975 |
| A.V.A.Limited | Farnham | 1930 |
| A.V.E Weld Construct Ltd | London | 2025 |
| A.V.Harris & SON Limited | Portsmouth | 1941 |
| A.V.O. Marine Systems Limited | Isle Of Wight | 2013 |
| A.W. (Europe) Limited | Halifax | 1980 |
| A.W. Clarke (Engineering) Limited | Oxford | 1966 |
| A.W. Engineering (Darwen) Limited | Gwynedd | 2002 |
| A.W. Engineering (Hereford) Ltd. | Hereford | 2003 |
| A.W. Fabrications Limited | Wellingborough | 2001 |
| A.W. Hainsworth Holdings Limited | Pudsey | 2008 |
| A.W. Hamilton Engineers Limited | Co Down | 2002 |
| A.W. Heat Pump Services Limited | Maldon | 2012 |
| A.W. Jeffreys (Southampton) Limited | Eastleigh | 1995 |
| A.W. Precision Engineering Limited | Wareham | 1997 |
| A.W. Raybould Limited | Cradley Heath | 1965 |
| A.W. Technology Limited | Leicestershire | 1990 |
| A.W.A. Refiners Limited | Harrow | 1991 |
| A.W.Gibbs(Holdings)Limited | Chigwell | 1970 |
| A.W.Hainsworth & Sons Limited | Pudsey | 1922 |
| A.W.Instruments Ltd | Blackburn | 2015 |
| A.W.Keil Ltd | Benfleet | 2006 |
| A.W.Precision Limited | Rugby | 1970 |
| A.Wardle & Company(Casters)Limited | Birmingham | 1964 |
| A.Warne & Company Limited | Morden Road | 1939 |
| A.Z.O. Limited | Halifax | 1993 |
| A/H Houseremoval Services Ltd | London | 2025 |
| A/W Joinery and Carpentry Limited | Hedon | 2021 |
| A1 Access Shutters & Maintenance Ltd. | Manchester | 2020 |
| A1 Aesthetics Laboratory Limited | Liverpool | 2018 |
| A1 Air Conditioning & Refrigeration Systems Limited | Bridgnorth | 2017 |
| A1 Aluminium Windows Ltd | Rochester | 2011 |
| A1 Anodising Limited | Sutton | 1998 |
| A1 Appliance Repairs Limited | Swanley | 2014 |
| A1 Auto Key Medic Ltd | Willenhall | 2022 |
| A1 Auto Security Ltd | Failsworth | 2013 |
| A1 Autocare (Northampton) Ltd | Northampton | 2016 |
| A1 Bedrooms and Kitchen Solutions Limited | Southall | 2013 |
| A1 Binding & Trimmings Ltd | Leicestershire | 2007 |
| A1 Binding Ltd | Leicester | 2014 |
| A1 Biomass Fuels Limited | Leyland | 2014 |
| A1 Blinds Tredegar Limited | Tredegar | 2014 |
| A1 Building Products Limited | St Asaph | 2010 |
| A1 Carbon Fibre Services Limited | Littlehampton | 2024 |
| A1 Coachworks Ltd | Hillsborough | 2000 |
| A1 Commercial Repairs (NI) Ltd | Enniskillen | 2014 |
| A1 Complete Security Ltd | Dudley | 2009 |
| A1 Concrete (Harrogate) Ltd | Knaresborough | 2017 |
| A1 Concrete MIX Ltd | Birmingham | 2021 |
| A1 Concrete Products (Cymru) Limited | Carmarthen | 2003 |
| A1 Cooked Meats Ltd | London | 2003 |
| A1 Denim Ltd | London | 2021 |
| A1 Developments Ltd | Canvey Island | 2019 |
| A1 Displays Ltd | Leeds | 2015 |
| A1 Electricals Limited | West Bromwich | 2008 |
| A1 Electronic Designs Ltd | Bridgend | 2012 |
| A1 Electronics Ltd | Doncaster | 2013 |
| A1 Energy Limited | Stanmore | 2018 |
| A1 Extraction Systems Limited | Birmingham | 2021 |
| A1 Fabrication Limited | Wisbech | 2017 |
| A1 Fabrications & Engineering Limited | Wellingborough | 2008 |
| A1 Fire Protection Ltd | Crawley | 2011 |
| A1 Fitted Kitchens Limited | Dartford | 2008 |
| A1 Fixquick Garage Doors Limited | Newbury | 2004 |
| A1 Foam Flex Ltd | Batley | 2020 |