| Ambe Homes Ltd | Real estate | 2021 |
| Ambe Infotech Ltd | Wholesale & retail | 2017 |
| Amberley House Barnet Limited | Households | 2004 |
| Amberley Property Investments Ltd | Real estate | 2021 |
| Amberlight Carpenters Ltd | Construction | 2018 |
| Ambor Ltd | Real estate | 2017 |
| Amcon Recruit Ltd | Administrative & support | 2020 |
| Amec Properties Limited | Real estate | 2020 |
| Amechia Holdings Ltd | Financial services | 2020 |
| Amega Holdings Ltd | Professional & scientific | 2021 |
| Amelias Restaurant Limited | Hospitality | 2024 |
| Amenico Ltd | Real estate | 2016 |
| Amesbury Court Enfield (Management) Limited | Households | 1971 |
| Amesbury Court Freehold Limited | Households | 2002 |
| Amex Associates Limited | Professional & scientific | 2004 |
| Ameya Software Systems Limited | Information & communication | 2012 |
| AMF Property Trading Ltd | Extraterritorial | 2008 |
| AMF Resolution Ltd. | Professional & scientific | 2017 |
| Amflow Bicycles (UK) Limited | Administrative & support | 2025 |
| Amie & Gracie Limited | Wholesale & retail | 2014 |
| Amina Rubinacci UK Ltd | Administrative & support | 2021 |
| Amitis New World Limited | Other services | 2017 |
| Amity Pharma Limited | Health & social care | 2007 |
| AMK Barbers Ltd | Other services | 2011 |
| AMK Rail Ltd | Construction | 2015 |
| AML Consulting Limited | Administrative & support | 2026 |
| AML Creative Ltd | Other services | 2019 |
| Amlz Ltd | Professional & scientific | 2019 |
| Amnc Properties Limited | Real estate | 2021 |
| Amnp Ltd | Real estate | 2014 |
| Amoeni Ltd | Administrative & support | 2015 |
| Amoli Oils Ltd | Manufacturing | 2025 |
| Amor Management Limited | Real estate | 2011 |
| Amore Limited | Manufacturing | 1999 |
| Amore Select Limited | Wholesale & retail | 2002 |
| Amorini Holdings Limited | Real estate | 2013 |
| Amos & Duarte Limited | Administrative & support | 2011 |
| AMP Groundworks London Ltd | Construction | 2024 |
| Amped & Armoured Limited | Wholesale & retail | 2025 |
| Ampersand London Limited | Real estate | 2024 |
| Ampthill SL Ltd | Real estate | 2022 |
| Amran Pharmacy Limited | Wholesale & retail | 2009 |
| Amran PS Limited | Real estate | 2024 |
| Amrc Holdings Ltd | Information & communication | 2024 |
| Amrc Properties Ltd | Real estate | 2024 |
| AMT Prestige Limited | Administrative & support | 2018 |
| Amulet Real Estate Limited | Other services | 2025 |
| AMV Solutions Ltd | Professional & scientific | 2024 |
| AMY Larkin Studios Ltd | Administrative & support | 2025 |
| AN & AR Investments Limited | Other services | 2019 |
| AN Consultancy Ltd | Other services | 2019 |
| AN Quarters Ltd | Real estate | 2023 |
| ANA & Co London Limited | Wholesale & retail | 2025 |
| ANA' Stasis Salons Ltd | Other services | 2020 |
| Anaash Holdings Limited | Extraterritorial | 2008 |
| Anaesthesia London Services Limited | Health & social care | 2004 |
| Analytiqa Associates Limited | Professional & scientific | 2002 |
| Ananas Media Ltd | Information & communication | 2021 |
| Anand Green Ltd | Extraterritorial | 2018 |
| Anaram Retail Ltd | Wholesale & retail | 2019 |
| Anasa Protect Ltd | Financial services | 2024 |
| Anastasia Grace Limited | Real estate | 2020 |
| Anastasia Mews Management Limited | Extraterritorial | 2012 |
| Anastasias Food Limited | Hospitality | 2018 |
| Anastassi Limited | Professional & scientific | 2017 |
| Anaxor Ltd | Manufacturing | 2025 |
| Anchor & Compass Group Limited | Real estate | 2026 |
| Anchor Storage Limited | Transport & logistics | 1987 |
| Anchord Ltd | Administrative & support | 2025 |
| Ancient Greek Sandals Ltd | Wholesale & retail | 2015 |
| AND Then WE Made Ltd | Financial services | 2024 |
| Andac Developments Ltd | Real estate | 2015 |
| Anders Financial Limited | Administrative & support | 1991 |
| Anderson & Sons Properties Ltd | Real estate | 2020 |
| Anderson 5026 Limited | Information & communication | 2006 |
| Anderson Taylor Limited | Administrative & support | 2007 |
| Andgl Ltd | Information & communication | 2021 |
| Andrea Harris Limited | Professional & scientific | 2016 |
| Andreas Plastiras Digital Ltd | Information & communication | 2018 |
| Andrei Anthony Ltd | Manufacturing | 2021 |
| Andrew Carney U.K. Limited | Construction | 2015 |
| Andrew H Ltd | Administrative & support | 2016 |
| Andrew JM Matthews Limited | Professional & scientific | 2018 |
| Andrew Miller Designs Limited | Professional & scientific | 2013 |
| Andrew Reed RTM Company Limited | Households | 2024 |
| Andrew Steele Consulting Ltd | Professional & scientific | 2015 |
| Andrew Steele LLP | | 2011 |
| Andrew Wood Associates Limited | Administrative & support | 2001 |
| Andrews & Dickens Projects Limited | Construction | 2012 |
| Andrews and Dickens Limited | Construction | 1993 |
| Andrews Heating Plumbing GAS Services Limited | Construction | 2019 |
| Andsan Limited | Real estate | 2010 |
| Andy Green Consulting Limited | Professional & scientific | 2024 |
| Andy Valentine Limited | Other services | 2008 |
| Anema Ltd | Administrative & support | 2019 |
| Anew Medical Consulting Limited | Education | 2022 |
| ANG Investments Limited | Information & communication | 2016 |
| Angel Build Ltd | Construction | 2019 |
| Angel Cafe London Ltd | Hospitality | 2021 |
| Angel Cafe Ltd | Hospitality | 2021 |