| A Littles & Co Ltd | Wholesale & retail | 2023 |
| A New Lease of Life Ltd | Wholesale & retail | 2022 |
| A P Green and Sons Ltd | Real estate | 2025 |
| A P Holloway Construction Limited | Construction | 2016 |
| A Qlcompany Ltd | Professional & scientific | 2015 |
| A$ Delivery Ltd | Transport & logistics | 2020 |
| A&A Travel Ltd | Administrative & support | 2025 |
| A&Asolutions Ltd | Professional & scientific | 2024 |
| A&J Cuisine Ltd | Hospitality | 2026 |
| A&J Tustian T/A Globetruckers U.K. Transport Ltd | Transport & logistics | 2022 |
| A&L Properties Limited | Real estate | 2025 |
| A&P Design and Build Limited | Arts & recreation | 2024 |
| A. Prin LLP | | 2016 |
| A.B.C. Advertising Partners Limited | Professional & scientific | 1978 |
| A.C. Solutions (G.B) Limited | Construction | 2004 |
| A.C.S Catering Limited | Extraterritorial | 2015 |
| A.C.V West Transport Ltd | Transport & logistics | 2023 |
| A.Crampton Electrical Ltd | Construction | 2023 |
| A.Damm Plumbing and Heating Ltd | Construction | 2025 |
| A.I.Motorsport Engineering Limited | Professional & scientific | 2022 |
| A.S.A.P. Driving and Industrial Services Limited | Transport & logistics | 1990 |
| A1 Cars Banbury Ltd | Transport & logistics | 2025 |
| A1 Courier U.K Ltd | Transport & logistics | 2025 |
| A1 J1 Properties Limited | Real estate | 2023 |
| A2B Castle Cars Limited | Transport & logistics | 2012 |
| A2B Recovery & Transport Ltd | Transport & logistics | 2024 |
| A9 Technicae Limited | Wholesale & retail | 2020 |
| Aardvarky Media Consulting Ltd | Information & communication | 2025 |
| Aayan Metal Ltd | Wholesale & retail | 2019 |
| Abacus Bookkeeping Consultant Ltd | Professional & scientific | 2020 |
| Abdia Trading Ltd | Wholesale & retail | 2018 |
| Abednego Limited | Administrative & support | 2017 |
| Aberdyfi Village Stores Ltd | Wholesale & retail | 2015 |
| Aberfoss Limited | Professional & scientific | 2019 |
| ABI Morris and Co Ltd | Arts & recreation | 2024 |
| Abingdon-On-Thames Plastering Limited | Construction | 2013 |
| Abis Logistics Ltd | Transport & logistics | 2025 |
| About Thyme Limited | Wholesale & retail | 2004 |
| About Your Accounts LLP | | 2021 |
| Absolute Auto Cars Ltd | Wholesale & retail | 2018 |
| Abstract Global Enterprises Ltd | Administrative & support | 2018 |
| Abubakerproperties Ltd | Administrative & support | 2026 |
| Abuseb Ltd | Transport & logistics | 2025 |
| AC Fit Ltd | Arts & recreation | 2022 |
| AC Traffic Limited | Professional & scientific | 2025 |
| ACA Advisory Ltd | Administrative & support | 2016 |
| Academy Consultancy and Design Limited | Construction | 2015 |
| Accass Ltd | Agriculture & fishing | 2020 |
| Accelerating Growth Fund Ltd | Professional & scientific | 2003 |
| Accounts.Golf Ltd | Professional & scientific | 2024 |
| Ace Cars Banbury Ltd | Transport & logistics | 2020 |
| Ace Green Property Limited | Real estate | 2015 |
| ACH Transport Solutions Ltd | Transport & logistics | 2025 |
| Achilles Ventures Ltd | Real estate | 2021 |
| Acorn Consulting Ltd | Professional & scientific | 2022 |
| Acorn Tree Work Limited | Agriculture & fishing | 2014 |
| Acqua Coir Limited | Wholesale & retail | 2018 |
| Acqua Plants Limited | Wholesale & retail | 2023 |
| Acqua Systems Limited | Wholesale & retail | 2018 |
| Acremans Arboriculture Ltd | Agriculture & fishing | 2007 |
| Activait Technology Limited | Information & communication | 2023 |
| Active Dog Essentials Limited | Other services | 2024 |
| Actus Developments Limited | Construction | 2020 |
| Acumentum I Fund Limited Partnership | | 2009 |
| AD Farm Media Limited | Information & communication | 2016 |
| Ad's Flavour's Fireplace Ltd | Other services | 2025 |
| Adalta Real (CN) Limited | Construction | 2021 |
| Adalta Real Holdings Limited | Construction | 2016 |
| Adalta Real Limited | Extraterritorial | 2012 |
| Adaltus Ltd | Wholesale & retail | 2018 |
| Adamsd Consulting Ltd | Professional & scientific | 2023 |
| Adapt Power Distribution Limited | Construction | 2012 |
| Adaptenz Ltd | Administrative & support | 2012 |
| ADD- Worth Accountancy Ltd | Professional & scientific | 2020 |
| Adderbury Electrical Services Limited | Construction | 2018 |
| Adderbury Property Limited | Real estate | 2016 |
| Adderbury Resorts Limited | Financial services | 2025 |
| Adderbury Store Ltd | Wholesale & retail | 2019 |
| Adept Removals Limited | Transport & logistics | 2018 |
| Adian Locums & Consultants Limited | Health & social care | 2012 |
| Adian Medical Advisory Limited | Professional & scientific | 2026 |
| Aditi Sport Ltd | Arts & recreation | 2019 |
| Adjacent Group Limited | Professional & scientific | 2022 |
| Adnd Housing Ltd | Real estate | 2025 |
| Adom-Ba Care Company Limited | Health & social care | 2025 |
| Adoption UK Charity | Other services | 2015 |
| ADP Studio Ltd | Professional & scientific | 2025 |
| ADU Investments Ltd | Real estate | 2025 |
| Advanced Business Concepts Ltd | Professional & scientific | 2002 |
| Advanced Communication Solutions Limited | Health & social care | 1996 |
| Advanced Facility Maintenance Ltd | Construction | 2014 |
| Advanced Medical Systems Ltd. | Wholesale & retail | 1997 |
| Advent 3D Limited | Wholesale & retail | 2020 |
| Advertising Site Management Limited | Real estate | 2000 |
| Advisor Profiles Ltd | Information & communication | 2024 |
| AE Technical Limited | Extraterritorial | 2014 |
| AEM Estates Ltd | Real estate | 2023 |
| AES (Angel Electrical Services) Ltd | Construction | 2006 |
| Afaftraders Ltd | Wholesale & retail | 2025 |
| AFC Upton Holdings Limited | Manufacturing | 2018 |