| Alturise Ltd | Professional & scientific | 2024 |
| Altus Property & Asset Management Limited | Real estate | 2021 |
| Altus PUB Co Ltd | Hospitality | 2020 |
| Altyn Tepe Ltd | Professional & scientific | 2019 |
| Alu-Passive Limited | Wholesale & retail | 2017 |
| Aludra Property Limited | Real estate | 2020 |
| Alula Wellness Limited | Arts & recreation | 2026 |
| Alutool (Preform DIE) Co. Limited | Manufacturing | 1968 |
| Alvar Healthcare Ltd | Administrative & support | 2023 |
| Alventra Consultants Limited | Wholesale & retail | 2025 |
| Alvernia Limited | Manufacturing | 2025 |
| Alveron Logistics Ltd | Wholesale & retail | 2008 |
| Alveston Grange Residents Company Limited | Households | 1994 |
| Alvin Barber Ltd | Other services | 2025 |
| Alvington Green Management Company Limited | Households | 2022 |
| Alvis and Clavey Ltd | Construction | 2022 |
| Alvis Brothers Limited | Agriculture & fishing | 1951 |
| Alvis Contracting Limited Liability Partnership | | 2002 |
| Alvis Developments Limited | Other services | 2015 |
| Alwaha Limited | Wholesale & retail | 2002 |
| Always Colourful Limited | Construction | 2021 |
| Always Developing Ltd | Education | 2025 |
| Always Letting & Management Ltd | Real estate | 2018 |
| Always on Point Barber Ltd | Other services | 2025 |
| Always Precious Ltd | Health & social care | 2011 |
| Always Properties Ltd | Real estate | 2017 |
| Alwayz on Point Ltd | Information & communication | 2021 |
| Alwaàn Ltd | Extraterritorial | 2023 |
| ALX Aero Ltd | Administrative & support | 2020 |
| ALY Media Network Ltd | Information & communication | 2025 |
| Alyonix Limited | Information & communication | 2025 |
| Alyssa Consulting Limited | Information & communication | 2012 |
| Alzan | Professional & scientific | 2018 |
| AM Bristol Ltd | Hospitality | 2019 |
| AM Cantle Limited | Real estate | 2017 |
| AM Capital Holdings Ltd | Financial services | 2025 |
| AM Construction Engineering Ltd | Construction | 2025 |
| AM Designed Solutions Ltd | Professional & scientific | 2013 |
| AM Glow Clinic Ltd | Health & social care | 2026 |
| AM Legal Consulting Limited | Professional & scientific | 2017 |
| AM Print Solutions Ltd | Administrative & support | 2009 |
| AM Property & Building Services Ltd | Construction | 2026 |
| AM Property Packaging Ltd | Real estate | 2025 |
| AM Property Services Inc Ltd | Construction | 2025 |
| AM Services (Bristol) Ltd | Construction | 2015 |
| AM to PM Tutoring Ltd | Education | 2022 |
| AM Trade Ltd | Hospitality | 2018 |
| AM1 Commerce Ltd | Wholesale & retail | 2025 |
| Amac Roofing Limited | Construction | 2015 |
| Amacinty Associates Limited | Professional & scientific | 2014 |
| Amadea Academy Limited | Education | 2024 |
| Amadeus Trading Co Ltd | Wholesale & retail | 2019 |
| Amadzone Ltd | Wholesale & retail | 2026 |
| Amae Property Limited | Real estate | 2016 |
| Amaise Cosmetics Ltd | Wholesale & retail | 2024 |
| Amaise Properties Ltd | Real estate | 2025 |
| Amaka Health Care Ltd | Health & social care | 2016 |
| Amal Consulting Ltd | Information & communication | 2024 |
| Amalgam 2020 Limited | Financial services | 2020 |
| Amalgam Collection Limited | Manufacturing | 2004 |
| Amalgam Holdings Limited | Professional & scientific | 2007 |
| Amalgam Modelmaking Limited | Professional & scientific | 2004 |
| Amalgamated Fisheries Limited | Agriculture & fishing | 2006 |
| Amalik Ltd | Health & social care | 2023 |
| Aman Hanifa Ltd | Hospitality | 2019 |
| Aman Pest Control Ltd | Administrative & support | 2016 |
| Amana Enterprise Limited | Wholesale & retail | 2025 |
| Amanda Fawcett Productions Ltd | Arts & recreation | 2025 |
| Amanda Lodge Limited | Professional & scientific | 2018 |
| Amanda Milton Limited | Professional & scientific | 2012 |
| Amandi Curae Limited | Health & social care | 2018 |
| Amango Limited | Professional & scientific | 2003 |
| Amani Films Ltd | Information & communication | 2021 |
| Amani Locums Ltd | Health & social care | 2021 |
| Amans Group Limited | Transport & logistics | 2015 |
| Amanu Healthcare Ltd | Health & social care | 2024 |
| Amar's Eyes Limited | Wholesale & retail | 2011 |
| Amara Soleil Ltd | Wholesale & retail | 2026 |
| Amarel-Ameroc Holdings Ltd | Financial services | 2024 |
| Amaretto Italian Sweet Ltd | Manufacturing | 2021 |
| Amari Bristol Ltd | Real estate | 2024 |
| Amari Developments SW Limited | Construction | 2022 |
| Amari Management SW Ltd | Households | 2023 |
| Amarillo Engineering Ltd. | Professional & scientific | 2016 |
| Amarin Rubber and Plastics Limited | Manufacturing | 2003 |
| Amariz Limited | Financial services | 1999 |
| Amarna Films Limited | Information & communication | 2024 |
| Amars Properties Ltd | Real estate | 2025 |
| Amaryllis Capital Limited | Financial services | 2025 |
| Amaryllis Ltd | Professional & scientific | 2023 |
| Amat N Jammeh and Sons Limited | Health & social care | 2014 |
| Amazing Blooms Ltd | Extraterritorial | 2019 |
| Amazon Curier Ltd | Transport & logistics | 2025 |
| Amazon Delivery Ltd | Transport & logistics | 2025 |
| AMB Engineering Services Limited | Administrative & support | 2021 |
| Amba Design Limited | Professional & scientific | 1997 |
| Ambar Hill Homes Ltd | Real estate | 2026 |
| Ambecx Limited | Professional & scientific | 2022 |
| Amber & White Ltd | Hospitality | 2024 |
| Amber Energy Solutions Ltd | Professional & scientific | 2009 |