| Antoun Consultancy Ltd | Professional & scientific | 2016 |
| Anview Limited | Wholesale & retail | 1997 |
| Anycourt Limited | Real estate | 1991 |
| AP Lienau Limited | Professional & scientific | 2010 |
| AP Secure Solutions Ltd | Administrative & support | 2021 |
| Apao Properties Limited | Real estate | 2019 |
| Apari Holdings Ltd | Financial services | 2020 |
| Apex Bespoke Fitouts Ltd | Construction | 2018 |
| Apex Designworks Ltd | Professional & scientific | 2026 |
| APH Fencing & Groundwork Limited | Construction | 2011 |
| APM Roofing Coventry Limited | Construction | 2014 |
| App Kandy Ltd | Information & communication | 2026 |
| Applegate Sleep Masks Limited | Wholesale & retail | 2025 |
| Applejacks Properties Ltd | Real estate | 2023 |
| Applied Behaviour Change Ltd | Professional & scientific | 2022 |
| Appoint US Services (Midlands) CIC | Health & social care | 2014 |
| Apps World Technologies Ltd | Information & communication | 2011 |
| Apricus Consulting Limited | Professional & scientific | 2021 |
| Apricus Properties Limited | Real estate | 2020 |
| Aprium Integrated Services Limited | Real estate | 2026 |
| APX Designworks Ltd | Professional & scientific | 2026 |
| Aqcel (UK) Limited | Wholesale & retail | 2026 |
| Aquaplus Window Cleaning Ltd | Other services | 2012 |
| Aquastone Ltd | Construction | 2025 |
| AR Accounting Services Limited | Professional & scientific | 2016 |
| AR Property Limited | Hospitality | 2015 |
| Aram Property Solutions Limited | Real estate | 2023 |
| Araminta ROW Ltd | Wholesale & retail | 2025 |
| Arapaho Development Limited | Construction | 2001 |
| ARB Pro Tree Services Limited | Administrative & support | 2017 |
| Arborfield Close Management Company Limited | Real estate | 2004 |
| ARC Developments (Midlands) Limited | Construction | 2025 |
| ARC Properties (Midlands) Limited | Real estate | 2025 |
| Arcade Party and Event Hire Ltd | Administrative & support | 2026 |
| Arcade Party and Events Ltd | Wholesale & retail | 2023 |
| Arches Lane Garage Limited | Wholesale & retail | 2003 |
| Archipelago Group Ltd | Wholesale & retail | 2024 |
| Archivar Ltd | Information & communication | 2026 |
| Archjai Ltd | Professional & scientific | 2023 |
| Arcstream 21 Ltd | Households | 2020 |
| Arden Aggregates Limited | Mining & quarrying | 2021 |
| Arden Hotel Investments Limited | Hospitality | 1999 |
| Arden Mechanical Services Limited | Wholesale & retail | 2018 |
| Arden Mount Group Ltd | Construction | 2024 |
| Ardenlaw (Rother ST) Limited | Real estate | 2021 |
| Ardenlaw Limited | Professional & scientific | 2015 |
| Ardenlaw Property Services Ltd | Real estate | 2021 |
| Ardent Automotive Works Ltd. | Professional & scientific | 2013 |
| Ardent Construction Services Limited | Construction | 2019 |
| Ardesignengineering Ltd | Professional & scientific | 2026 |
| Ardnabel Limited | Professional & scientific | 2023 |
| Arduis Tacmed Ltd | Administrative & support | 2025 |
| Area 404 Ltd | Information & communication | 2020 |
| ARG Pensions (1974) Limited | Extraterritorial | 1954 |
| ARG Trustees (1970) Limited | Extraterritorial | 1968 |
| Aria-Amk Limited | Information & communication | 2004 |
| Ariajosh Properties Ltd | Real estate | 2019 |
| Arimal Trading Ltd | Wholesale & retail | 2026 |
| ARK Property and Housing Group Ltd | Real estate | 2021 |
| Arkworld UK Limited | Wholesale & retail | 2003 |
| Armitt Homes Ltd | Real estate | 2025 |
| Armstrong and Diperri Limited | Real estate | 2023 |
| Armstrong Associates Limited | Professional & scientific | 2016 |
| Aroma Cafe & Bar Limited | Hospitality | 2016 |
| Arriba Wellness Clubs Limited | Wholesale & retail | 2010 |
| Arriga CRM Limited | Information & communication | 2016 |
| Arrow Court Management Limited | Households | 2003 |
| Arsm Food and Wine Ltd | Wholesale & retail | 2026 |
| Art of the Hunger Limited | Extraterritorial | 2016 |
| Artful Fade & Shave Ltd | Other services | 2024 |
| Artificial Integration Limited | Information & communication | 2025 |
| Artisan Floors Ltd | Wholesale & retail | 2011 |
| Arts Uplift Community Interest Company | Arts & recreation | 2016 |
| Artspan CIC | Education | 2023 |
| Arxyne Ltd | Information & communication | 2026 |
| Aryatex Limited | Wholesale & retail | 2016 |
| AS Venue Ltd | Hospitality | 2026 |
| Asbilt Ltd | Construction | 2024 |
| Ascension Vocals Ltd | Information & communication | 2025 |
| Ascent Financial Consulting Limited | Financial services | 2021 |
| Ascon Associates Limited | Administrative & support | 2008 |
| Ascot Consulting (UK) Ltd | Extraterritorial | 2007 |
| ASE Technology Limited | Information & communication | 2023 |
| ASH Bryant Ltd | Administrative & support | 2024 |
| ASH Hearing Limited | Health & social care | 2017 |
| Ashbur London Limited | Wholesale & retail | 2025 |
| Ashburton CPM Ltd | Administrative & support | 2011 |
| Ashex Exhibition Services Ltd | Construction | 2021 |
| Ashex Limited | Construction | 2019 |
| Ashford Blake Ltd | Manufacturing | 2024 |
| Ashleys Electronic Ltd | Extraterritorial | 2021 |
| Ashmore (AJ) Holdings Ltd | Financial services | 2024 |
| Ashmore Accountants & Business Advisors Limited | Professional & scientific | 2025 |
| Ashorne Hill (Trading) Limited | Real estate | 2005 |
| Ashorne Limited | Construction | 1973 |
| Ashorne Pubs Ltd | Hospitality | 2007 |
| Ashwood Property (Warwickshire) Limited | Construction | 2019 |
| Asiasol Ltd | Wholesale & retail | 2025 |
| ASK Avril Ltd | Administrative & support | 2025 |
| ASK Deansgate Limited | Hospitality | 2017 |