| Apexonline Solutions Ltd | Wholesale & retail | 2025 |
| Aphrodite Menopause Clinic Limited | Health & social care | 2023 |
| Apphia Consulting Limited | Professional & scientific | 2018 |
| Apphia Holdings Ltd | Professional & scientific | 2022 |
| Apphia Property One Ltd | Real estate | 2022 |
| Appia Construction Ltd | Construction | 2020 |
| Apsley Bags Ltd | Manufacturing | 2017 |
| APW Optics Ltd | Health & social care | 2021 |
| Aqualink Limited | Real estate | 1990 |
| Aravis Bighorn Services Limited | Information & communication | 2011 |
| Aravis Yogo Limited | Wholesale & retail | 2011 |
| Arborpost Limited | Construction | 2022 |
| ARC Modular Ltd | Manufacturing | 2026 |
| Arcus Products Limited | Construction | 2015 |
| Ardnob Ltd | Other services | 2025 |
| Area Four Industries (UK) Ltd | Manufacturing | 2001 |
| Argyl Management Limited | Real estate | 2003 |
| Arkenstone Construction Ltd | Construction | 2024 |
| Arkie FM Limited | Administrative & support | 2025 |
| Arli Trans Ltd | Transport & logistics | 2022 |
| Aroma WAX Melt Ltd | Manufacturing | 2026 |
| Arrosys Limited | Information & communication | 2002 |
| Art and Chain Music Group Ltd | Arts & recreation | 2025 |
| Art on Glass Holdings Ltd | Financial services | 2018 |
| Art on Glass Limited | Manufacturing | 1994 |
| Arthur Markillie Holdings Limited | Financial services | 2023 |
| Arthur Markillie Limited | Agriculture & fishing | 1958 |
| Arthur's Delivery Limited | Transport & logistics | 2016 |
| Artybee Limited | Wholesale & retail | 2022 |
| Arxarma Ltd | Information & communication | 2009 |
| Ashewell Developments Limited | Construction | 2010 |
| Ashlar Developments Limited | Construction | 2017 |
| Ashmore Assets Limited | Real estate | 2025 |
| Ashmore Developments Ltd | Construction | 2015 |
| Ashmore Holdings Group Limited | Professional & scientific | 2025 |
| Ashmore Lettings Ltd | Real estate | 2017 |
| ASL Brickwork & Groundworks Ltd | Construction | 2022 |
| Aspect Trade Hub Ltd | Professional & scientific | 2026 |
| Aspire Homes (East Anglia) Ltd. | Real estate | 2020 |
| Aspire Logistics Limited | Transport & logistics | 2022 |
| Asqai Ltd. | Information & communication | 2023 |
| Association of Amateur Mixed Martial Arts Ltd | Arts & recreation | 2022 |
| Astall Pathology Services Limited | Health & social care | 2017 |
| AT Auto & Spares Ltd | Wholesale & retail | 2026 |
| Ataa Building Services UK Limited | Construction | 2025 |
| ATB Security Services Ltd | Administrative & support | 2016 |
| Atlantic Island Properties Limited | Professional & scientific | 2015 |
| Atmosphere Intercontinental Airlines UK PVT Limited | Transport & logistics | 2017 |
| Atomic Rose Ltd. | Professional & scientific | 2016 |
| Attempting Technology Limited | Information & communication | 1998 |
| Audrius Trans & Co Ltd | Transport & logistics | 2016 |
| Auksine Masina Ltd | Wholesale & retail | 2025 |
| Aura's Autos Limited | Wholesale & retail | 2025 |
| Ausman Modular Structures Ltd | Manufacturing | 2022 |
| Auto Infatuation Ltd | Wholesale & retail | 2025 |
| Autointegration Ltd | Information & communication | 2013 |
| Automaniac Service Ltd | Wholesale & retail | 2011 |
| Automax 66 Ltd | Wholesale & retail | 2023 |
| Autoskinz Limited | Wholesale & retail | 2015 |
| Autospa Express Ltd | Administrative & support | 2024 |
| Autospeed Centre Ltd | Wholesale & retail | 2020 |
| Avaddon Academy Ltd | Arts & recreation | 2026 |
| Avalon Consortium Ltd | Professional & scientific | 1999 |
| Avalon Construction (Southern) Limited | Construction | 2002 |
| Avant Manufacturing Limited | Manufacturing | 2021 |
| Avantgarde Construction Limited | Professional & scientific | 2001 |
| Avln Ltd | Wholesale & retail | 2025 |
| Avormen Apparel Ltd | Wholesale & retail | 2021 |
| Ax-Tech Solutions Ltd | Other services | 2025 |
| AX1 Interiors Limited | Professional & scientific | 2026 |
| AYF Limited | Manufacturing | 2015 |
| Aylmer Lodge Enterprises Ltd | Manufacturing | 2019 |
| Ayton & Mckeown Limited | Manufacturing | 2005 |
| Azalea Property Services Ltd | Real estate | 2020 |
| B & C Contracting Ltd | Administrative & support | 2023 |
| B & D Refrigeration Services Ltd | Construction | 2023 |
| B & J Estates Limited | Real estate | 2003 |
| B & W Electrical Services Ltd | Construction | 2019 |
| B D M Plastering Limited | Construction | 2006 |
| B D Upton Builders Limited | Construction | 2006 |
| B H H Chatteris Ltd | Hospitality | 2020 |
| B P Combine Harvesters Ltd | Wholesale & retail | 2016 |
| B. H. Porter & SON Breakers Limited | Wholesale & retail | 2013 |
| B. J. Plant Hire Limited | Construction | 2007 |
| B.H. Porter & SON Limited | Water & waste | 2004 |
| B.W. Mack (Machinery) Limited | Wholesale & retail | 1975 |
| BA Mortgage Consultancy Services Ltd | Financial services | 2023 |
| Badr Development Company Limited | Administrative & support | 2008 |
| Bailey Ltd | Administrative & support | 2003 |
| Baites IT Support Ltd | Information & communication | 2014 |
| Balkan Bazaar Ltd | Wholesale & retail | 2024 |
| Baltika Grocery Shop Ltd | Wholesale & retail | 2021 |
| Bambers Holdings Limited | Real estate | 2024 |
| Bambers Limited | Real estate | 2021 |
| Bamboo Print Ltd | Manufacturing | 2008 |
| Bank House Beverages Limited | Manufacturing | 2025 |
| Banner Signs Limited | Manufacturing | 2024 |
| Barker Safety Services Ltd | Extraterritorial | 2025 |
| Barks and Bubbles Ltd | Other services | 2020 |
| Barnard Developments (Wisbech) Ltd | Real estate | 2024 |