| Amigo Ventures Ltd | Professional & scientific | 2021 |
| Ammas Food Ltd | Wholesale & retail | 2024 |
| Amoc Ltd | Wholesale & retail | 2022 |
| Amor Health Limited | Health & social care | 2024 |
| Amorge Limited | Other services | 2025 |
| Amour Property Staging Ltd | Professional & scientific | 2025 |
| Ampd Lifestyle Limited | Wholesale & retail | 2025 |
| Ampersand Philanthropy Limited | Professional & scientific | 2025 |
| Ampho Artisan Foods Limited | Manufacturing | 2020 |
| AMS Business Support Services Limited | Professional & scientific | 1971 |
| AMT Marketing Limited | Administrative & support | 2000 |
| AMY Wicks Young Photography Ltd | Professional & scientific | 2025 |
| Anaj Restaurant and Takeaway Ltd. | Hospitality | 2015 |
| Anakieva Capital and Equity Ltd | Financial services | 2025 |
| Anakieva Couture Ltd | Wholesale & retail | 2025 |
| Analogue Automotive Limited | Wholesale & retail | 2013 |
| Analogue Cars (UK) Limited | Wholesale & retail | 2015 |
| Analytical People Limited | Professional & scientific | 2002 |
| Analytics Advisers Limited | Administrative & support | 2015 |
| Analyticslab Limited | Information & communication | 2018 |
| Anand Living Ltd | Real estate | 2024 |
| Anayaa Homes Ltd | Real estate | 2024 |
| Anchor & Horseshoes Limited | Hospitality | 2023 |
| Ancoop Limited | Hospitality | 2015 |
| Ancy Limited | Real estate | 2017 |
| Anders Hagstrom Limited | Professional & scientific | 2020 |
| Anderson Data Ltd | Administrative & support | 2017 |
| Anderson Veterinary Orthopaedic Consultancy Limited | Professional & scientific | 2017 |
| Anderton Music Retailing Limited | Wholesale & retail | 2008 |
| Andrew and Eileen Taylor Ltd | Professional & scientific | 2016 |
| Andrew Glencross Engineering Ltd | Professional & scientific | 2014 |
| Andrew Heard Limited | Wholesale & retail | 2018 |
| Andrews Holding Group Limited | Financial services | 2020 |
| Andrews Property South East Limited | Real estate | 2020 |
| Andris Consulting Limited | Other services | 2024 |
| Andro Pharmaceuticals Ltd | Wholesale & retail | 2022 |
| Angel Hotel Guildford Limited | Hospitality | 2010 |
| Angel&Ivi Services Ltd | Wholesale & retail | 2020 |
| Angle Partnerships Limited | Professional & scientific | 2006 |
| Angle Technology Licensing Limited | Extraterritorial | 1998 |
| Angle Technology Limited | Professional & scientific | 1994 |
| Angle Technology Ventures Limited | Professional & scientific | 1999 |
| Anglebuy Limited | Real estate | 1988 |
| Anglo East India Company Limited | Professional & scientific | 2012 |
| Anglo International Group Limited | Professional & scientific | 1984 |
| Anglo Urban Investments Ltd | Construction | 2009 |
| Anglo-European Concessions Limited | Professional & scientific | 1939 |
| Angus Solution Ltd | Administrative & support | 2020 |
| Anjali Medicare Limited | Health & social care | 2025 |
| Anna Nina Ltd | Wholesale & retail | 2024 |
| Anna Bullus Limited | Professional & scientific | 2011 |
| Anna Keeble Limited | Other services | 2020 |
| Anna Louisa Interiors Limited | Wholesale & retail | 2020 |
| Anne Cuthbert Group Ltd | Real estate | 2025 |
| Anne Milton Ltd | Professional & scientific | 2020 |
| Annison Associates Ltd | Administrative & support | 2016 |
| Ansa Healthcare 24/7 Recruitment Agency Ltd | Administrative & support | 2018 |
| Antarctic Refrigeration & Air Conditioning Services Limited | Construction | 2009 |
| Antenova Limited | Information & communication | 1999 |
| Antermony | Financial services | 2015 |
| Anthrometric Solutions Limited | Professional & scientific | 2025 |
| Anyards Properties Limited | Real estate | 2011 |
| Anynet Limited | Information & communication | 2019 |
| AOK Bikes Limited | Wholesale & retail | 2014 |
| Aola Investment Ltd | Construction | 2026 |
| AOM Close Limited | Real estate | 2026 |
| AP Clean UP Services Ltd | Administrative & support | 2026 |
| AP Lifestyle Ltd | Real estate | 2008 |
| Apcer Life Sciences Holding Limited | Administrative & support | 2019 |
| Apcer Life Sciences Ltd. | Administrative & support | 2009 |
| Apeldoorn Properties Limited | Real estate | 2013 |
| Aperitas Limited | Information & communication | 2014 |
| Apex Pioneers Limited | Professional & scientific | 2023 |
| Apex Premier Estates Ltd | Real estate | 2024 |
| Apex Tyres Hub Limited | Wholesale & retail | 2026 |
| Apical Consulting Limited | Professional & scientific | 2010 |
| Apis Asset Holdings Ltd | Real estate | 2019 |
| Apis Investments Ltd | Financial services | 2017 |
| Aplaniq Ltd | Information & communication | 2026 |
| APM Electrical Services Limited | Construction | 2016 |
| Apne Limited | Financial services | 2015 |
| Apne Properties Limited | Real estate | 2016 |
| Apogee Space Consulting Limited | Transport & logistics | 2026 |
| Apollo Commissioning Services Ltd | Energy | 2018 |
| Apollo Consulting Solutions Limited | Information & communication | 2024 |
| Apollo Precision Ltd | Manufacturing | 2020 |
| Apopsis Ltd | Professional & scientific | 2017 |
| Apotheca London Skincare Ltd | Wholesale & retail | 2017 |
| Appia Healthcare Limited | Wholesale & retail | 2011 |
| Apposite Technology Ltd | Information & communication | 2014 |
| Approved Used Bang & Olufsen Limited | Wholesale & retail | 2020 |
| Appsessorize Limited | Information & communication | 2012 |
| APR Educational Consultants Ltd | Information & communication | 2016 |
| Apricot Rose Ltd | Information & communication | 2026 |
| Aptosoft Limited | Information & communication | 2007 |
| Apus Technology Ltd | Information & communication | 2023 |
| Apxi Trading Ltd | Information & communication | 2023 |
| Aqua Flux Technology Ltd | Financial services | 2025 |
| Aqua Genesis LAB Ltd | Construction | 2025 |
| Aqua Headspa Ltd | Other services | 2024 |