| A.I.M. Consultancy Limited | Oxfordshire | 1992 |
| A.I.Motorsport Engineering Limited | Banbury | 2022 |
| A.I.R Accounting Services Ltd | Fareham | 2024 |
| A.I.S Solutions Ltd | London | 2021 |
| A.I.S. (Holdings) Limited | Kidderminster | 2005 |
| A.I.W Consultancy Limited | Edgware | 2016 |
| A.Inspecservices Ltd | Stoke-On-Trent | 2025 |
| A.J Care Consultancy Ltd | Sudbury | 2025 |
| A.J Gold Consultancy Ltd | London | 2021 |
| A.J Hunter Electrical Services Ltd | Liverpool | 2025 |
| A.J Training and Consultancy Ltd | Llandrindod Wells | 2019 |
| A.J Walsh Ltd | Cookstown | 2026 |
| A.J. Accounting Services (Kent) Limited | Sittingbourne | 2022 |
| A.J. Adams Consultancy Ltd | Aberdeen | 2021 |
| A.J. Anton (U.K.) Limited | Uxbridge | 1989 |
| A.J. Betteridge Consultancy Limited | London | 2016 |
| A.J. Croll & Company Ltd. | Aberdeen | 2026 |
| A.J. Dalton Group Limited | Stratford-Upon-Avon | 2003 |
| A.J. Energy Consultants Limited | Colchester | 2007 |
| A.J. Glew Limited | Warwickshire | 2002 |
| A.J. International Consultancy Limited | Kilmarnock | 2013 |
| A.J. International Consultancy Specialists Ltd | Halifax | 2023 |
| A.J. Jones Consultants Ltd | Liverpool | 2023 |
| A.J. Mcdonough (Electrical Engineering) Limited | Norwich | 1999 |
| A.J. Meechan Ltd. | Warwick | 1995 |
| A.J. Pearman Aviation Services Limited | Liss | 2008 |
| A.J. Peasley & Co Limited | Wednesbury | 2003 |
| A.J. Poels & Company Limited | Barnes | 1932 |
| A.J. Retter Limited | Middlesex | 1997 |
| A.J. Sands Limited | Exeter | 1991 |
| A.J. Schofield Limited | London | 1925 |
| A.J. Sewell Limited | Hertford | 2011 |
| A.J.B. Consulting and Brokering Ltd | Kingston Upon Thames | 2025 |
| A.J.B. Scholes Limited | Kirkwall | 2008 |
| A.J.Brown Holdings Limited | Deal | 2019 |
| A.J.Burton Limited | Kent | 2003 |
| A.J.C Consulting Ltd | Upminster | 2025 |
| A.J.C Contracting Services Limited | North Shields | 2025 |
| A.J.Chappell Consulting Ltd | Grimsby | 2023 |
| A.J.Dyke & SON Limited | Essex | 1973 |
| A.J.H. Surveying Services Limited | Sussex | 1999 |
| A.J.Harman Consulting Limited | Beaconsfield | 2019 |
| A.J.J. Marine Ltd | Hamilton | 2022 |
| A.J.Knowles Limited | Worcester | 1964 |
| A.J.L. Sales Ltd | Newton Aycliffe | 2024 |
| A.J.M. Robertson Consulting Limited | Preston | 2005 |
| A.J.P Keating Management Limited | Minehead | 2026 |
| A.J.P. (Holdings) Company | Sheffield | 1962 |
| A.J.P. Design Limited | Newbury | 1990 |
| A.J.P.R. Engineering Limited | Aberdeen | 2001 |
| A.J.Peace Consultants Ltd | St. Asaph | 2019 |
| A.J.Pledger and Co. (Metals) Limited | Stamford | 1969 |
| A.J.R. Cook Ltd | Maidstone | 2020 |
| A.J.R. Taylor (Construction) Limited | Lincoln | 1970 |
| A.J.S. Precision Engineering Limited | Chorley | 2007 |
| A.J.W. Design Limited | Spalding | 1999 |
| A.J.W. Diving Limited | Chelmsford | 2015 |
| A.J.W. Surveying Limited | Gravesend | 2011 |
| A.Johni Life Science Consulting Ltd | Horsham | 2023 |
| A.Jones Engineering Ltd | Chesterfield | 2024 |
| A.K Decorations & Events Ltd | Slough | 2023 |
| A.K Pharmaceutical Ltd | Doncaster | 2021 |
| A.K. & Co (Consultancy Services) Limited | East Sussex | 2001 |
| A.K. & Co. (Accountancy Services) Limited | Hove | 1992 |
| A.K. Accountancy Services Limited | Buckinghamshire | 2002 |
| A.K. Bureau Ltd. | London | 2011 |
| A.K. Willcox Limited | Southampton | 1984 |
| A.K.Accounting Services Ltd | Salisbury | 2007 |
| A.K.D. Consultancy Services Ltd | London | 2017 |
| A.K.E. Group Limited | Worcester | 2001 |
| A.K.H. Limited | Chorley | 2015 |
| A.K.I. E&I Design Limited | Glasgow | 2023 |
| A.K.L.A. Investments Limited | Dundee | 1978 |
| A.K.Larsen Management Consulting Ltd. | London | 2016 |
| A.K.M. Professional Services Limited | Cardiff | 2013 |
| A.Knox Consulting Ltd | Hillsborough | 2026 |
| A.L Select Ltd | Ilford | 2019 |
| A.L. FRY Systems Engineering Ltd | Bristol | 2022 |
| A.L. Holland Ltd | Shrewsbury | 2012 |
| A.L. Roddy Limited | Luton | 2003 |
| A.L. Signature Event Management Ltd | London | 2021 |
| A.L. Steed Limited | | 1978 |
| A.L. Work in Progress Ltd | Harrow | 2021 |
| A.L.A.Q Limited | London | 2024 |
| A.L.D. Holdings Limited | Nottingham | 2001 |
| A.L.E. UK Holdings Limited | Hixon | 2005 |
| A.L.G Fashion Ltd | London | 2019 |
| A.L.L Mechanical Services Ltd | Bromley | 2026 |
| A.L.M Renewable Energy Service Limited | Grimsby | 2026 |
| A.L.R. Consulting Limited | Arundel | 2004 |
| A.L.R. Legal Services Ltd | Bromley | 2008 |
| A.L.T Landscapes Ltd | Petworth | 2025 |
| A.L.T. Accountants Limited | South Yorkshire | 2003 |
| A.L.Ward Consulting Limited | Bedford | 2022 |
| A.Lemay Ltd | Harlow | 2019 |
| A.Lungarini Ltd | London | 2026 |
| A.Lydon. Pipeline Services Ltd | Solihull | 2021 |
| A.M Baxter and Company Ltd | Elgin | 2021 |
| A.M Builders and Developers Global Ltd | Harrow | 2025 |
| A.M Business Consultancy Limited | Ilford | 2013 |