| AM Pre-Clinical Services Ltd | Professional & scientific | 2013 |
| AMA Services Limited | Professional & scientific | 2009 |
| Amarant Investments Limited | Real estate | 2021 |
| Amazing India UK Ltd | Hospitality | 2025 |
| Amberwood Developments Limited | Real estate | 1987 |
| AMC Sports Academy Limited | Education | 2022 |
| Amcc Ltd. | Administrative & support | 1980 |
| AMR Computer Supplies Ltd | Information & communication | 2004 |
| Amron Home Help Ltd | Health & social care | 2021 |
| Amtri Veritas Limited | Professional & scientific | 1994 |
| AMW Consulting Partners LLP | | 2004 |
| AMW Family Limited | Hospitality | 2025 |
| Amy-Sha Mother of Hairdressing Limited | Other services | 2018 |
| Analog Implant Laboratory Limited | Manufacturing | 2000 |
| Analytical Scientific Hardware Instruments Limited | Financial services | 1996 |
| Analytical Technology International Limited | Manufacturing | 2001 |
| Analytics and Insights Consulting Ltd | Information & communication | 2026 |
| Anan Properties Limited | Real estate | 2016 |
| Anarosh Ltd | Hospitality | 2026 |
| Anattic Ltd | Information & communication | 2015 |
| Ancaster House (Richmond Hill) Management Company Limited | Real estate | 2015 |
| Ancoats Engineering Ltd | Professional & scientific | 2021 |
| Ancona Alpha Ltd | Professional & scientific | 2012 |
| AND Business Enterprises Ltd | Construction | 2025 |
| Andina Property Group Limited | Real estate | 2025 |
| Andrac Limited | Wholesale & retail | 2017 |
| Andrac Medical Limited | Wholesale & retail | 2017 |
| Andrac Services Limited | Wholesale & retail | 2017 |
| Andrew Broomhead Properties Limited | Real estate | 2021 |
| Andrew Ellis Planning Consultants Ltd | Professional & scientific | 2011 |
| Andrew J Hyde Property Consultant Ltd | Professional & scientific | 2019 |
| Andrew LEA Finance Limited | Professional & scientific | 2012 |
| Andrew R Higginbotham Ltd | Professional & scientific | 2026 |
| Andrew Smith Funeral Services Ltd | Other services | 2015 |
| Andrew Wall Photography Ltd | Professional & scientific | 2023 |
| Andrews Pharmacy Limited | Wholesale & retail | 2001 |
| Andy DOW Limited | Information & communication | 2013 |
| Animag Ltd | Wholesale & retail | 2023 |
| Anjo (Broxton) Limited | Professional & scientific | 2002 |
| Ankh & Horus Ltd | Professional & scientific | 2022 |
| Anne Clews Consulting Limited | Administrative & support | 2007 |
| Annual Property Maintenance Survey Limited | Construction | 2021 |
| Annulus Ltd | Manufacturing | 2026 |
| Anodos Resources Limited | Administrative & support | 2023 |
| Anomaly Media Ltd | Health & social care | 2009 |
| Anson Park Limited | Information & communication | 2024 |
| Ansontrading Limited | Wholesale & retail | 2025 |
| Antibody Applications Limited | Professional & scientific | 2009 |
| Antic Developments Ltd | Construction | 2021 |
| Antique Ceramic Restoration Ltd | Other services | 2008 |
| Antique Interiors Online Ltd | Wholesale & retail | 2025 |
| AOS Alshallal Ltd | Transport & logistics | 2026 |
| APC Electrical Contractors Limited | Construction | 2015 |
| APC Manchester Limited | Transport & logistics | 1998 |
| Aperture Software Technologies Ltd | Information & communication | 2015 |
| Apicem Limited | Information & communication | 2015 |
| Apn-Dmc Limited | Administrative & support | 2015 |
| Apocalypse Fitness Limited | Arts & recreation | 2020 |
| Apocalypse Media Limited | Information & communication | 2022 |
| Apollo Capital Ltd | Financial services | 2020 |
| Apollo Health Axis Limited | Information & communication | 2025 |
| Apotunity Limited | Professional & scientific | 2016 |
| Appalachian Ltd | Information & communication | 2021 |
| Appi Developments Ltd | Construction | 2023 |
| Appletree Associates Ltd | Professional & scientific | 2024 |
| Apqs Consultancy Ltd | Professional & scientific | 2019 |
| APW Properties Limited | Construction | 2013 |
| Aqis Technologies Ltd | Professional & scientific | 1982 |
| Aquapi Ltd | Hospitality | 2022 |
| Aquarius PUB Co Ltd | Hospitality | 2017 |
| Aquatec Window Cleaning Services Limited | Other services | 2009 |
| AQUILA46 Limited | Hospitality | 2013 |
| AR Mobiles Tyres Ltd | Wholesale & retail | 2025 |
| Arbdirect Ltd | Agriculture & fishing | 2023 |
| Arbour Living Holdings Limited | Financial services | 2026 |
| Arbour Living Limited | Construction | 2023 |
| ARC Consultancy Services Limited | Professional & scientific | 2025 |
| ARC Purchasing Management Limited | Professional & scientific | 2007 |
| Arcadian Estates (North West) Limited | Real estate | 1999 |
| Archers Marketing Ltd | Professional & scientific | 2023 |
| Archibo Limited | Hospitality | 2004 |
| Architectingbusiness Limited | Information & communication | 2015 |
| Architects' Publishing Partnership Limited | Information & communication | 1988 |
| Architectural, Design, & Technology Consulting Limited | Professional & scientific | 2023 |
| Arden Sports Lighting Limited | Construction | 2000 |
| Aready Ltd | Information & communication | 2020 |
| Argyle Street Limited | Real estate | 2013 |
| Aria Fresca Limited | Wholesale & retail | 2023 |
| Arighi Bianchi (1854) Limited | Wholesale & retail | 2016 |
| Arighi Bianchi Holdings Limited | Real estate | 2012 |
| Arighi Bianchi Property Company Limited | Real estate | 2018 |
| Aristan Laboratories International Ltd | Manufacturing | 2024 |
| Aristan Laboratories UK Ltd | Wholesale & retail | 2024 |
| Ariva Renewables Ltd | Construction | 2021 |
| Arlington IT Limited | Information & communication | 2022 |
| Armadillo Industrial Limited | Wholesale & retail | 2013 |
| Armadillo SEC Ltd | Other services | 2016 |
| Armadillo Sports Design Limited | Arts & recreation | 2000 |
| Armoury Court Management Limited | Households | 1988 |
| Armstrong Pharmacology Ltd | Professional & scientific | 2020 |