| Almsbury LLP | | 2021 |
| Aloysius Okeke Ltd | Health & social care | 2019 |
| Alpha Hire (Cotswold) Limited | Administrative & support | 2001 |
| Alpha Independent Estate Agents Ltd | Real estate | 2013 |
| Alpha India Ltd | Information & communication | 2021 |
| Alpha Papa Tango Marketing Limited | Administrative & support | 2010 |
| Alpha Plus Guardian Services Limited | Administrative & support | 2003 |
| Alpha Renovations Ltd | Construction | 2024 |
| Alpha Wellbeing Associates Limited | Health & social care | 2010 |
| Alpha Whiskey Limited | Financial services | 2014 |
| ALR Advisory Limited | Information & communication | 2023 |
| ALS Automation Group Limited | Financial services | 2022 |
| ALS Fabrications Limited | Manufacturing | 2023 |
| ALS International Holdings Limited | Financial services | 2025 |
| ALS Mechatronic Limited | Manufacturing | 2002 |
| ALS Tyres Ltd | Wholesale & retail | 2009 |
| ALS11 Ltd | Wholesale & retail | 2019 |
| Alscourt Residents Association Limited | Households | 1981 |
| Alshafi Ltd | Hospitality | 2021 |
| Alshaibi Dental Academy & Recruitment Ltd | Education | 2025 |
| Alsto-Heat Limited | Construction | 2001 |
| Alston Lodge Residents Association Limited | Households | 2001 |
| Alstone Communications Ltd | Professional & scientific | 2023 |
| Alstone Lane Trading Estate Ltd | Real estate | 2018 |
| Alstone Mews (Management) Company Limited | Households | 2002 |
| ALT Nuvem Limited | Professional & scientific | 2024 |
| Altamira Project Solutions Limited | Administrative & support | 2013 |
| Alterinvest Capital Ltd. | Real estate | 2011 |
| Altido Group Limited | Information & communication | 2009 |
| Altior Accountancy & Taxation Ltd | Professional & scientific | 2022 |
| Altior Asset Management Ltd | Professional & scientific | 2020 |
| Altiora Recruitment Europe Limited | Administrative & support | 2019 |
| Altitude Alloy Towers Limited | Construction | 1998 |
| Altitude Scaffolding Access Limited | Construction | 2000 |
| Altitude-Uavsolutions Ltd | Wholesale & retail | 2023 |
| Altius Capital Ltd | Financial services | 2012 |
| Alto Executive Ltd | Extraterritorial | 2012 |
| Alto Resources (Cheltenham) LLP | | 2010 |
| Altvia Solutions Limited | Extraterritorial | 2016 |
| Alume Ltd | Professional & scientific | 2020 |
| AM Burch Services Limited | Professional & scientific | 2024 |
| AM Davis Heating & Plumbing Limited | Construction | 2015 |
| AM Mayer Ltd | Professional & scientific | 2020 |
| AM Rodrigues Ltd | Real estate | 2022 |
| AM Whelan Property (Cheltenham) Ltd | Real estate | 2020 |
| AMA Executive Holdings Ltd | Financial services | 2025 |
| AMA Executive Limited | Manufacturing | 2019 |
| Amalfipizzaco Ltd | Hospitality | 2021 |
| Amaranthine Home Ltd | Wholesale & retail | 2019 |
| Amazing Touch Healthcare Limited | Health & social care | 2023 |
| Amazing Touching Point Cleaning Company Limited | Administrative & support | 2022 |
| AMB Classic Solutions Limited | Wholesale & retail | 2025 |
| AMB Homes Ltd | Real estate | 2022 |
| Ambarii Limited | Administrative & support | 2023 |
| Amber Palace Limited | Hospitality | 2019 |
| Amberley Healthcare Limited | Health & social care | 1995 |
| Amberley House UK Limited | Real estate | 2016 |
| Ambernae Ltd | Professional & scientific | 2024 |
| Amberoid Properties Ltd | Real estate | 2022 |
| Ambii Ltd | Other services | 2016 |
| Ambitious Eagle Ltd | Information & communication | 2024 |
| Ambleside House Limited | Administrative & support | 2017 |
| Ambrose Property Ltd | Real estate | 2025 |
| AMC Associates Limited | Real estate | 2022 |
| AMC Fitness Limited | Information & communication | 1997 |
| Amedeo Aversa Ltd | Wholesale & retail | 2018 |
| Amelea Willow Limited | Real estate | 2022 |
| Amen Accounting Services Ltd | Professional & scientific | 2025 |
| Amere Advisors Ltd | Professional & scientific | 2025 |
| American RV Parts UK Ltd | Wholesale & retail | 2018 |
| AMF Electrical Services Ltd | Construction | 2018 |
| Amicis Care Limited | Health & social care | 2013 |
| Amicus HR Ltd | Administrative & support | 2025 |
| Amicus People Ltd | Administrative & support | 2026 |
| Amie Skincare Limited | Extraterritorial | 2011 |
| Amietta International Limited | Information & communication | 2006 |
| Amij Hair & Beauty Limited | Other services | 2019 |
| Amit U.K. Ltd | Transport & logistics | 2001 |
| Amks Properties Ltd | Real estate | 2025 |
| Amlh Limited | Professional & scientific | 2023 |
| AMM Bookkeeping & Accountancy Ltd | Extraterritorial | 2024 |
| Ammonite Developments LLP | | 2023 |
| Amosonos Limited | Information & communication | 2019 |
| AMP Property Group Developments Ltd | Construction | 2023 |
| AMP Property Group Ltd | Real estate | 2018 |
| Amtig Consult Limited | Administrative & support | 2012 |
| AMW Events Limited | Other services | 2014 |
| AMW Management Solutions Limited | Professional & scientific | 2023 |
| AMY Bastin Dance Limited | Arts & recreation | 2025 |
| AMY Cuthbertson Associates Limited | Professional & scientific | 2022 |
| Amyron Limited | Transport & logistics | 2024 |
| Anaavila Consulting Limited | Information & communication | 2013 |
| Anaesthetic Expert Reporting Limited | Health & social care | 2015 |
| Anarchy GIN Ltd | Wholesale & retail | 2021 |
| Anaxxim Ltd | Professional & scientific | 2025 |
| ANC Orthopaedia Limited | Health & social care | 2023 |
| Anchor Agencies Limited | Transport & logistics | 1987 |
| Anchor Coffee Ltd | Hospitality | 2026 |
| AND Fauna Limited | Wholesale & retail | 2023 |
| Andante Travels Limited | Administrative & support | 1985 |