| A.D Property Consulting Limited | Chorleywood | 2025 |
| A.D. Beard Limited | Cockermouth | 2000 |
| A.D. Beattie Ltd. | Falkirk | 2009 |
| A.D. BLY Aircraft Leasing Limited | Hitchin | 2000 |
| A.D. Design Consultants Limited | Suffolk | 2001 |
| A.D. Maclean Tree Management Ltd | Winchester | 2011 |
| A.D. Madureira Peterborough Ltd | Peterborough | 2024 |
| A.D. Webley Limited | Solihull | 2012 |
| A.D. Works Limited | Oxfordshire | 2008 |
| A.D.A.M.A.N.T.I.U.M Limited | Enfield | 2025 |
| A.D.D. Options Ltd | Falkirk | 2022 |
| A.D.E Regeneration Ltd | Nottingham | 2016 |
| A.D.G. Plant Hire (Forfar) Ltd | Forfar | 2003 |
| A.D.Growing Solutions Ltd | Horncastle | 2021 |
| A.D.H. Ross Ltd. | Ross Shire | 2002 |
| A.D.J. Limited | Preston | 1991 |
| A.D.K (Plant) Services Limited | Chatham | 2012 |
| A.D.L. Security Services Limited | London | 1987 |
| A.D.M. Peterborough Ltd | Peterborough | 2025 |
| A.D.P. Supplies Limited | Crowthorne | 1997 |
| A.D.S Marquees Ltd | Ruislip, | 2026 |
| A.D.S. Hire Services Limited | Warrington | 1999 |
| A.D.T Exterior Cleaning Ltd | Liverpool | 2025 |
| A.E. Beckett & Sons (Developments) Limited | Birmingham | 1973 |
| A.E. LEE Recruitment Limited | Droitwich | 2010 |
| A.E. Rout & Sons Limited | Ipswich | 1977 |
| A.E.D. Rent UK Limited | Loudwater | 2010 |
| A.E.G. Rigging and Antenna Services Ltd | Dalry | 2020 |
| A.E.Lawson Plumbing & Heating Ltd | Bromley | 2013 |
| A.E.S. (Bath) Ltd | Bradford-On-Avon | 2003 |
| A.E.S.(Uk) Limited | Coventry | 2009 |
| A.E.T Home Improvements Ltd | Dunfermline | 2009 |
| A.E.T. Ltd | Bishop Auckland | 1997 |
| A.F PCO Rentals Ltd | Harrow | 2024 |
| A.F Scaffolding Limited | Crawley | 2016 |
| A.F. Selection Limited | Sutton Coldfield | 1988 |
| A.F.E. Academy CIC | Dagenham | 2026 |
| A.F.I. Limited | Northumberland | 1990 |
| A.F.P Garden Services Limited | Derbyshire | 2003 |
| A.Farrell.Events Ltd | Romsey | 2026 |
| A.Frankley Limited | Gloucester | 2022 |
| A.G Grounds Maintenance Limited | Wymondham | 2022 |
| A.G Paving,Groundworks - Landscape and Building Contractors Ltd | Bampton | 2025 |
| A.G Protection Ltd | London | 2023 |
| A.G Yachting Limited | London | 2024 |
| A.G. Gates Limited | Kendal | 1932 |
| A.G. Maclean Ltd. | Tain | 2003 |
| A.G. Salon Limited | Congleton | 2011 |
| A.G. Security (Norwich) Limited | Norwich | 2016 |
| A.G. Security Limited | Chester Le Street | 2016 |
| A.G. Vehicle Rentals Limited | Stoke On Trent | 2010 |
| A.G.Bird Contracting Ltd | Liphook | 2025 |
| A.G.G Recruitment Agency Ltd | Coventry | 2024 |
| A.G.G. Direction Limited | Sheffield | 2006 |
| A.G.Gas-Tek Ltd | Glasgow | 2009 |
| A.G.L. Consulting Limited | Lynch Wood, Peterborough | 2006 |
| A.G.M. (2017) Limited | London | 2017 |
| A.G.M. Exhibition Services Limited | Goffs Oak | 1996 |
| A.G.Potter (Framlingham) Limited | Woodbridge | 1928 |
| A.G.R. Logistics Limited | Newquay | 2012 |
| A.G.R. Pendrill (Chiropody) Limited | Wolverhampton | 2007 |
| A.G.S Castings Ltd | London | 2015 |
| A.Grant Window Cleaning Services Ltd | Nelson | 2016 |
| A.H & N.H Properties Limited | Redditch | 1971 |
| A.H Garden Maintenance Limited | Hull | 2023 |
| A.H Recruitment Limited | London | 2026 |
| A.H.G Buying Ltd | Rotherham | 2022 |
| A.H.N.Construction Ltd | Glasgow | 2016 |
| A.H.S Cleaning Services Limited | Mansfield | 2025 |
| A.H.V. Passive Fire Protection Ltd | Scarborough | 2023 |
| A.H@Height Limited | Ilchester | 2016 |
| A.Hand Services Limited | Telford | 2000 |
| A.I. Events Limited | Slough | 2024 |
| A.I. Exhibitions Ltd | Benfleet | 2021 |
| A.I. Locksmith Service Ltd | Belfast | 2016 |
| A.I. Translating Limited | Salford | 2008 |
| A.I.D Expert Ltd | London | 2020 |
| A.I.M. (North) Ltd. | Edinburgh | 2007 |
| A.I.M. Integrated Solutions Ltd | Markfield | 2013 |
| A.I.M.S. Precision Ltd. | Chichester | 1996 |
| A.I.T. Services (UK) Limited | | 1989 |
| A.Ibrahim & Co. Consultants Ltd | Ilford | 2026 |
| A.In.T Holding Limited | London | 2023 |
| A.J & D.J Muggridge Ltd | St Leonards On Sea | 2003 |
| A.J Lawn Financial Solutions Limited | Morpeth | 2023 |
| A.J. - Northern Blitz Ltd | Bradford | 2022 |
| A.J. Bayliss Petroleum Engineers Ltd | Harrogate | 2000 |
| A.J. Capewell Properties Limited | Birmingham | 1997 |
| A.J. Cladding Limited | Larkhall | 2002 |
| A.J. Clancy (Investments) Limited | Portstewart | 1998 |
| A.J. Craig & Sons (Industrial Cleaners) Limited | Angus | 1977 |
| A.J. Executive Investments Limited | Aberdeen | 1980 |
| A.J. Gammond Limited | Malvern | 1973 |
| A.J. Hicks Associates Ltd | Berks | 2007 |
| A.J. Marshall (Holdings) Ltd | Thirsk | 2010 |
| A.J. Mazur Ltd | Corby | 2009 |
| A.J. Systems (UK) Limited | Horsham | 1991 |
| A.J.B. Trees & Ground Care Limited | Cannock | 2021 |
| A.J.D.M Holdings Ltd | London | 2024 |
| A.J.Fencing Ltd | Barnet | 2016 |