| AFS Restorations Limited | Wholesale & retail | 2026 |
| Agcap Limited | Financial services | 2016 |
| Ager Renovations Ltd | Construction | 2018 |
| Agilis Holdings Ltd | Real estate | 2022 |
| Agility Data Solutions Limited | Extraterritorial | 2012 |
| Agnito UK Limited | Professional & scientific | 2004 |
| Agri Aerial Drones (UK) Limited | Agriculture & fishing | 2024 |
| Agri Frontier Capital Ltd | Financial services | 2024 |
| Agri Frontier Ltd | Professional & scientific | 2010 |
| Agrimensore Ltd | Professional & scientific | 2023 |
| Agrimove Ltd | Wholesale & retail | 2026 |
| AH Catering Cirencester Ltd | Hospitality | 2021 |
| AH Software Solutions Limited | Information & communication | 2013 |
| Ahbb Consultancy Ltd | Professional & scientific | 2022 |
| AI Training Services Ltd. | Information & communication | 1996 |
| AIMS4LIFE Ltd | Financial services | 2017 |
| Air Salvage International Limited | Transport & logistics | 1997 |
| Aircon Worldwide Limited | Other services | 2006 |
| Airport and Navigation Solutions Limited | Professional & scientific | 2013 |
| AIT Manuals Ltd | Transport & logistics | 2004 |
| Aiuto Ltd | Professional & scientific | 2009 |
| AJ & PW Mason LLP | | 2010 |
| AJ Properties (UK) Limited | Real estate | 2003 |
| AJ Support Services Limited | Professional & scientific | 2014 |
| AJC Future Homes Limited | Construction | 2025 |
| Akers Construction Ltd | Construction | 2013 |
| Akewood Consulting Ltd | Professional & scientific | 2023 |
| Akturkon Ltd | Professional & scientific | 2016 |
| Alan Brown Technical Services Limited | Professional & scientific | 1998 |
| Alan Sutton Publishing Limited | Professional & scientific | 2013 |
| Albee Limited | Administrative & support | 2008 |
| Albion Hold 1 Limited | Real estate | 2023 |
| Albion Lepus Limited | Professional & scientific | 2024 |
| Albion Quarters Limited | Construction | 2021 |
| Alderwood Forge Ltd | Manufacturing | 2026 |
| Alexander Square Partners Limited | Administrative & support | 2018 |
| Alexander Square Partners Nominees Limited | Administrative & support | 2024 |
| Alfalah Taxi Services Ltd | Transport & logistics | 2025 |
| Alfco Investments Limited | Real estate | 1983 |
| Alfred Ashley Limited | Real estate | 1982 |
| Alice Boggis-Rolfe Fine Art Limited | Arts & recreation | 2018 |
| Aligleo Limited | Transport & logistics | 2022 |
| Alison Bradley Legal Services Ltd | Professional & scientific | 2013 |
| Alison Fielden & Co Limited | Professional & scientific | 2020 |
| Alkali Blue Ltd | Information & communication | 2017 |
| Allen’S Railway Solutions Limited | Construction | 2026 |
| Allied Distribution Limited | Wholesale & retail | 1996 |
| Allium Accountancy Ltd | Professional & scientific | 2010 |
| Almost Alchemy Limited | Manufacturing | 2016 |
| Alpines Tree Surgery Ltd | Administrative & support | 2022 |
| Altair Helicopters and Professional Services Ltd | Other services | 2012 |
| Altim Software Limited | Financial services | 1998 |
| Amayna Ltd | Real estate | 2021 |
| Amgco One Ltd | Administrative & support | 2017 |
| Amity Consulting Services Limited | Professional & scientific | 2025 |
| Ampm Marketing Limited | Professional & scientific | 2008 |
| Ampney Crucis Cricket Club Ltd | Arts & recreation | 2026 |
| ANB Financial Consultancy Ltd | Financial services | 2019 |
| Andrew Miller Accountants Limited | Professional & scientific | 2014 |
| Angel Bureau of Investigations Ltd Ltd | Administrative & support | 2026 |
| Angelite Your Way Ltd | Extraterritorial | 2015 |
| Anglo East Ltd | Agriculture & fishing | 2014 |
| ANI Skincare Ltd | Other services | 2024 |
| Anicore Limited | Extraterritorial | 2014 |
| Anna Hiett Ltd | Professional & scientific | 2022 |
| Annabelle’S Bridal Boutique Ltd | Wholesale & retail | 2023 |
| Antalya Barber GL7 Ltd | Other services | 2022 |
| Anteros Capital Limited | Financial services | 2014 |
| Anteros Property Limited | Administrative & support | 1994 |
| Apollo Commercial Interiors Limited | Construction | 2021 |
| Apoq Ltd | Information & communication | 2024 |
| APT Civils Ltd | Construction | 2023 |
| Aqua Flowers Limited | Other services | 2015 |
| Arambha Ltd | Wholesale & retail | 2022 |
| Arbor Landscapes (Tree Service) Ltd | Administrative & support | 2022 |
| Archihaus Ltd | Construction | 2024 |
| Arcstone Ltd | Construction | 2024 |
| Area 10 Fitness Limited | Arts & recreation | 2019 |
| Argent House Wealth Management Limited | Financial services | 2009 |
| ARK Homes Design Limited | Construction | 2017 |
| Arkenside Mews Management Company Limited | Households | 2012 |
| Arlingdon Farm Management Company Limited | Households | 2002 |
| Armadillo Locksmiths Limited | Administrative & support | 2015 |
| Armstrong Burton Limited | Extraterritorial | 2008 |
| Arquitis Financial Management Limited | Financial services | 2016 |
| Arris Fort Security Ltd | Administrative & support | 2014 |
| Artemis Lifestyle Limited | Construction | 2017 |
| Artemis Living Limited | Construction | 2017 |
| Arter Consulting Limited | Professional & scientific | 2023 |
| Arvoo UK Ltd | Wholesale & retail | 2024 |
| ARW Consultancy Limited | Professional & scientific | 2011 |
| AS Claridge Limited | Health & social care | 2014 |
| ASC Cirencester Ltd | Other services | 2020 |
| Ascari Finance Ltd | Financial services | 2022 |
| Ascension CNI Consultancy Limited | Professional & scientific | 2026 |
| ASF Contracting Limited | Agriculture & fishing | 2025 |
| ASH SAW Mills Ltd | Administrative & support | 2022 |
| Ashcroft Capacitors Limited | Wholesale & retail | 1993 |
| Ashcroft Ceramic Capacitors Limited | Manufacturing | 2003 |
| Ashcroft Tetbury Limited | Professional & scientific | 2014 |