| A. Electrical Contractors Ltd | Hayle | 2024 |
| A. Evans & SON (Contractors) Limited | Buxton | 1978 |
| A. F. Payne Limited | Bognor Regis | 2011 |
| A. Figg Builders Limited | Leigh-On-Sea | 2003 |
| A. Frame Limited | Bedford | 2008 |
| A. Fraser Builders Ltd. | Kyle | 2003 |
| A. G. B. Contractors Limited | Surrey | 2002 |
| A. G. Builders Limited | Pewsey | 1992 |
| A. G. Building & Joinery Limited | Cheshire | 1999 |
| A. G. Green Garage Doors and Remotes Limited | Market Drayton | 1991 |
| A. G. Lawrence (Plastering) Limited | Tamworth | 1985 |
| A. G. Partnership Limited | Manchester | 2016 |
| A. G. Pentelow Groundworks Limited | Rushden | 2011 |
| A. G. Topham Limited | Nottingham | 2016 |
| A. G. Utilities Limited | London | 2017 |
| A. Garrett Electrical Services Ltd | Northampton | 2017 |
| A. Gaskell & SON (Roofing Contractors) Limited | Nelson | 2003 |
| A. Gilbert Limited | Stafford | 2010 |
| A. Glew Plastering & Rendering Ltd | Hartlepool | 2021 |
| A. Grant (Gairloch) Limited | Tain | 1999 |
| A. Grays Roofing Ltd | Renfrew | 2015 |
| A. H. Building Contractors Limited | Mattingley | 2002 |
| A. H. Electrical Contractors Limited | Winsford | 2003 |
| A. H. Electrical Systems Limited | Ashbourne | 2007 |
| A. H.Bailey Limited | Doncaster | 2003 |
| A. Hadham Construction Limited | Cheshunt | 2011 |
| A. Hadzic Construction Limited | Coventry | 2015 |
| A. HAK UK Limited | Stafford | 2015 |
| A. Hames Limited | Nottingham | 2013 |
| A. Hammond & Sons Limited | Sturminster Newton | 1959 |
| A. Harding Construction Ltd | Eaglescliffe | 2007 |
| A. Harrington Civils Limited | Folkestone | 2019 |
| A. Harris Contractors Limited | Lichfield | 2002 |
| A. Haylock and SON Building Services Ltd. | Reigate | 1996 |
| A. Hesketh GAS Services Ltd | Manchester | 2018 |
| A. Hewitt & Sons Builders Limited | Derby | 2003 |
| A. Higgins Contracts Limited | Magherafelt | 2022 |
| A. Hinsley Limited | Nottingham | 1960 |
| A. Holmes Building Services Limited | Nottingham | 2018 |
| A. Holmes Properties Ltd | Ballyclare | 2007 |
| A. Howard & SON Ltd | Norwich | 2021 |
| A. Hudson Builders Limited | Dereham | 2013 |
| A. Hull Electrical Limited | | 1996 |
| A. Hurry Plumbing Limited | Basildon | 2018 |
| A. I. Electrics Limited | Benfleet | 2015 |
| A. Ilendo Property Development Limited | Bushey | 2004 |
| A. J Brown Electrical Contracting Ltd | Porthmadog | 2013 |
| A. J. Atkins Excavation Contractors Limited | Bradford | 2003 |
| A. J. Beamish Electrical Contractors Limited | Worksop | 2004 |
| A. J. Borley Limited | Staplefield | 2003 |
| A. J. Building (Hull) Limited | Hull | 1996 |
| A. J. Bull Scaffolding Limited | Southampton | 1999 |
| A. J. Bullingham Building Services Ltd | Cheltenham | 2003 |
| A. J. Burkitt Limited | Lincoln | 2013 |
| A. J. Callaway Ltd | Hungerford | 2020 |
| A. J. Clacher Limited | Darlington | 1979 |
| A. J. Construction Limited | Northampton | 2014 |
| A. J. Doughty Limited | Birmingham | 2000 |
| A. J. Hall Limited | Derbyshire | 2005 |
| A. J. K. Services Limited | Fareham | 1998 |
| A. J. Morrison Limited | Munlochy | 2003 |
| A. J. Raucki & SON Limited | Taunton | 2009 |
| A. J. S. Brickwork Consultancy Limited | Basildon | 2003 |
| A. J. Shingler Drylining Limited | Dudley | 2021 |
| A. J. Surfacing & Paving Limited | Doncaster | 2023 |
| A. J. Tait Ltd | Ashford | 2015 |
| A. J. Walton Electrical Ltd | Polegate | 2019 |
| A. J. Watson (Construction) Limited | Essex | 2007 |
| A. J. Williams Insulation Limited | Leigh-On-Sea | 2007 |
| A. Johnson Home Developments Ltd | Reading | 2017 |
| A. Johnson Joinery Ltd. | Windermere | 2007 |
| A. Jones & SON (GAS Services) Limited | St. Asaph | 2006 |
| A. Jones Plastering Contractors Ltd | Maesteg | 2024 |
| A. Jones Roofing & Cladding Limited | Northamptonshire | 2007 |
| A. Joy Limited | Braintree | 2012 |
| A. K. Harfield Steeplejacks Ltd | London | 2020 |
| A. K. London Constructions Limited | West Drayton | 2006 |
| A. K. Medical Centre Limited | Benfleet | 2002 |
| A. Kalam's - Homes Limited | Hayes | 2024 |
| A. Kalasnikovas Ltd | Dagenham | 2014 |
| A. Kapllaj Limited | London | 2012 |
| A. Karim M. Deen Imperium Ltd | Reading | 2023 |
| A. Kennedy Construction Limited | Pudsey | 2004 |
| A. King Contracts Limited | Kinross | 1999 |
| A. Kirson Roofing Services Limited | | 2007 |
| A. Klass Ductwork Installation Ltd | Market Drayton | 2016 |
| A. L. F. Tiling Ltd | Wakefield | 2014 |
| A. L. Robinson (Contract Services) Limited | S Wales | 2005 |
| A. Lamb Associates Limited | London | 2001 |
| A. Langham Builders Limited | Reading | 2003 |
| A. LEE Paving Limited | Durham | 2007 |
| A. Lees Bricklaying Contractors Ltd | Gosport | 1997 |
| A. Lench Building Contractors Ltd. | Newcastle-Under-Lyme | 2003 |
| A. Lennox Homes Limited | Lanark | 2005 |
| A. Littlewood Plastering Limited | Barnsley | 2021 |
| A. Lloyd Electrical & Solar Limited | Swansea | 2010 |
| A. Lukosius Ltd | London | 2016 |
| A. Lusha Brickwork Ltd | Reading | 2021 |
| A. M. Formwork Limited | Blackburn | 2019 |
| A. M. Install Limited | Romford | 2015 |