| A&I Interiors Ltd | Construction | 2022 |
| A&J Coles Ltd | Extraterritorial | 2010 |
| A&J Deliveries Ltd | Transport & logistics | 2020 |
| A&J Future Construction Limited | Construction | 2023 |
| A&J Trans Ltd | Transport & logistics | 2025 |
| A&K Oils Ltd | Wholesale & retail | 2025 |
| A&L Eurocleaner Ltd | Administrative & support | 2021 |
| A&L Investment Ltd | Real estate | 2022 |
| A&Lc Associates Limited | Health & social care | 2016 |
| A&Lc Properties Limited | Real estate | 2021 |
| A&M Freight Ltd | Transport & logistics | 2021 |
| A&M Management and Services Ltd | Transport & logistics | 2024 |
| A&N Jawaid Consultants Ltd | Real estate | 2025 |
| A&P Stowage Ltd | Transport & logistics | 2022 |
| A&R Hunsbury Investments Ltd | Real estate | 2025 |
| A&S Appliance Valeting Ltd | Administrative & support | 2019 |
| A&S Nadeem Ltd | Wholesale & retail | 2024 |
| A&Sm Company Ltd | Wholesale & retail | 2026 |
| A&V Solution Ltd | Construction | 2026 |
| A&W Contractors Ltd | Construction | 2023 |
| A-A Bros Racing Limited | Arts & recreation | 2022 |
| A-A-T Plumbing Heating Ltd | Construction | 2019 |
| A-Lift Crane Hire Limited | Construction | 2004 |
| A-Run Transportation Ltd | Transport & logistics | 2022 |
| A-Span Limited | Construction | 1996 |
| A-Star Gardening & Landscaping Ltd | Administrative & support | 2024 |
| A-True Care Ltd | Health & social care | 2025 |
| A-Z Industries Ltd | Wholesale & retail | 2022 |
| A-Zelkova Limited | Information & communication | 2004 |
| A. & a. Electrical Services Limited | Construction | 1995 |
| A. D. and G. M. Jeyes Limited | Hospitality | 1981 |
| A. D. Leggett Limited | Construction | 2024 |
| A. Franklin & SON Limited | Manufacturing | 2022 |
| A. Garrett Electrical Services Ltd | Construction | 2017 |
| A. J. Construction Limited | Construction | 2014 |
| A. M. C. (U.K.) Fasteners Limited | Manufacturing | 1977 |
| A. S. Roofing Limited | Construction | 2021 |
| A. W. Associates (UK) Limited | Transport & logistics | 2004 |
| A.& a. O'Neill Ltd | Professional & scientific | 2009 |
| A.B.Y. Artisans Ltd | Construction | 2026 |
| A.Bell & Co,Limited | Construction | 1905 |
| A.C Electrical E.U Ltd. | | 2004 |
| A.C. Mayes Limited | Education | 2016 |
| A.C.L International Ltd | Wholesale & retail | 2025 |
| A.D.A Distribution Ltd | Construction | 2020 |
| A.Driving 2019 Ltd | Transport & logistics | 2019 |
| A.E. Maiden Estates Limited | Real estate | 1996 |
| A.E.P. UK Limited | Manufacturing | 2004 |
| A.E.S. Corporate Limited | Financial services | 2023 |
| A.E.S. Rescue Services Limited | Transport & logistics | 2004 |
| A.G.S. Acoustic Materials Limited | Wholesale & retail | 1995 |
| A.Godrich & Co.,Limited | Real estate | 1933 |
| A.H. Civils & Construction Limited | Construction | 2025 |
| A.J. Block Paving Contractors Limited | Construction | 1987 |
| A.J. Jones Tipper & Grab Hire Ltd | Construction | 2003 |
| A.J.Mackaness Limited | Real estate | 1946 |
| A.J.Md Ltd | Construction | 2025 |
| A.J.R. Electrical Services (Banbury) Limited | Construction | 2007 |
| A.K & S Limited | Transport & logistics | 2007 |
| A.K.Z Security Ltd | Administrative & support | 2014 |
| A.Major Transport and Logistics 1501 Ltd | Transport & logistics | 2025 |
| A.Miah Properties Limited | Real estate | 2026 |
| A.P. Faulkner (Heating) Limited | Construction | 1964 |
| A.P.S Promotions Ltd | Wholesale & retail | 2003 |
| A.R. Dixon Display Limited | Manufacturing | 1978 |
| A.R.T. Global Education Ltd | Education | 2024 |
| A.S.Leisure Ltd | Wholesale & retail | 2018 |
| A.T.E. Solutions Limited | Manufacturing | 2002 |
| A.V.G Haulage&Warehousing Ltd | Transport & logistics | 2022 |
| A.V.R. Fixings Ltd. | Wholesale & retail | 1989 |
| A.V.T.V. Limited | Information & communication | 1990 |
| A.Watts & Sons Limited | Wholesale & retail | 1928 |
| A1 Autocare (Northampton) Ltd | Manufacturing | 2016 |
| A1 Chimney Sweep Northants Ltd | Administrative & support | 2014 |
| A1 Felt Roofing Ltd | Professional & scientific | 2015 |
| A1 Grab Hire Limited | Transport & logistics | 2013 |
| A1 Group (UK) Limited | Transport & logistics | 2010 |
| A1 Holdco Ltd | Financial services | 2024 |
| A1 Logistics Ltd | Transport & logistics | 2017 |
| A1 Manpower Agency Ltd | Administrative & support | 2025 |
| A1 MOT Centre Northampton Ltd | Wholesale & retail | 2019 |
| A1 Property Group Ltd | Real estate | 2017 |
| A1 Remedials Limited | Construction | 2012 |
| A1 Retro Sprays Ltd | Other services | 2019 |
| A10 Homes Ltd | Real estate | 2024 |
| A14 Building Plastics Limited | Wholesale & retail | 2009 |
| A14 Glass Rooms Limited | Construction | 2016 |
| A19 Groundworks Ltd | Construction | 2022 |
| A20 Cars Private Hire Services Ltd | Transport & logistics | 2020 |
| A2AUTO&TRANSPORT Limited | Wholesale & retail | 2025 |
| A2B Car Transport Ltd | Transport & logistics | 2019 |
| A2CARE Limited | Administrative & support | 2022 |
| A2E Services Limited | Construction | 2008 |
| A2N Consulting Limited | Other services | 2024 |
| A2Z Software Solutions Limited | Information & communication | 2013 |
| A46 Service Corporation Ltd | Other services | 2018 |
| A74 Enforcement Ltd | Administrative & support | 2026 |
| AA & NN Ltd | Wholesale & retail | 2025 |
| AA Academic Network Solutions Ltd | Education | 2023 |
| AA Care Yorkshire Ltd | Health & social care | 2019 |