| Amenity Trees Limited | Administrative & support | 2006 |
| Amera Ltd | Professional & scientific | 2014 |
| Amersham Hill Sports Club Limited | Arts & recreation | 1960 |
| Amersham Mobile Tyre Service Ltd | Wholesale & retail | 2022 |
| Amersham Road Development Ltd | Real estate | 2016 |
| Amethyst Phoenix Limited | Real estate | 2023 |
| Ametora Ltd | Wholesale & retail | 2020 |
| AMH Property Organisation Ltd | Real estate | 2021 |
| Amhospitality Limited | Hospitality | 2019 |
| Amiin & Co Ltd | Wholesale & retail | 2024 |
| Amin Autos Ltd | Wholesale & retail | 2026 |
| Amin Network Consultants Ltd | Information & communication | 2026 |
| Aminu Investments Limited | Extraterritorial | 2021 |
| Amiri AI Ltd | Information & communication | 2025 |
| Amity’S A&K Ltd | Other services | 2024 |
| Amjid & Umbreen Choudhry LLP | | 2024 |
| AMM Group Holdings Ltd | Information & communication | 2025 |
| Ammonite Psychotherapy Limited | Health & social care | 2010 |
| Amna Property Limited | Real estate | 2026 |
| Amodeo Creative Limited | Information & communication | 2012 |
| Amour DU Jardin Limited | Professional & scientific | 2020 |
| AMP27 Limited | Information & communication | 2023 |
| Amparo Prosthetics Ltd | Manufacturing | 2021 |
| Amplus Production Limited | Professional & scientific | 1998 |
| Ampy High Wycombe Ltd | Professional & scientific | 2025 |
| AMR Accounting Services Limited | Professional & scientific | 2023 |
| AMR Investment Management Limited | Real estate | 2021 |
| AMR Property Holdings Limited | Financial services | 2021 |
| AMS Auto Door Solutions Ltd | Construction | 2025 |
| AMT Safety Consultancy Ltd | Administrative & support | 2024 |
| Amtech Solutions Ltd | Information & communication | 2006 |
| AMW Media Ltd | Professional & scientific | 2024 |
| AMX Accountants Limited | Professional & scientific | 1998 |
| AMY Nails & Beauty Ltd | Other services | 2024 |
| AMY Nails & Spa Limited | Other services | 2018 |
| Amzaum Ltd | Information & communication | 2021 |
| Amzflydelivery Ltd | Wholesale & retail | 2023 |
| Amzm Ltd | Other services | 2022 |
| Amzvish Limited | Information & communication | 2023 |
| AN Autoz Limited | Wholesale & retail | 2025 |
| AN Consultation Ltd | Professional & scientific | 2014 |
| An.Heaven Ltd | Wholesale & retail | 2022 |
| Anaesthetic Locums Ltd | Professional & scientific | 2021 |
| Anakor Holdings Limited | Administrative & support | 2020 |
| Analogue Wonderland Limited | Wholesale & retail | 2018 |
| Analysticsbi Ltd | Information & communication | 2013 |
| Anandam Oralcare Limited | Health & social care | 2022 |
| Anasa London Limited | Manufacturing | 2025 |
| Anaya's Holdings Ltd | Real estate | 2020 |
| Anchor & Bloom Limited | Real estate | 2025 |
| Ancient Crafts Limited | Extraterritorial | 2010 |
| Andacard Online (Smc-Private) Limited | Wholesale & retail | 2021 |
| Andaria Holdings Limited | Financial services | 2024 |
| Andav Engineering Services Ltd | Manufacturing | 2021 |
| Andee's Cafe Limited | Hospitality | 2025 |
| Andes Entertainment Ltd | Information & communication | 2026 |
| Andica Limited | Information & communication | 2004 |
| Andica Software Limited | Information & communication | 2004 |
| Andica.Com Limited | Information & communication | 2009 |
| Andika Limited | Extraterritorial | 2023 |
| Andika.Com Limited | Extraterritorial | 2023 |
| Andrecarservice Ltd | Wholesale & retail | 2025 |
| Andrei Plastering Ltd | Construction | 2021 |
| Andrew Baskeyfield Limited | Information & communication | 2015 |
| Andrew Biffa Aggregates Limited | Administrative & support | 2016 |
| Andrew Bullman Property Management Ltd | Real estate | 2022 |
| Andrew Callaghan Photography Limited | Professional & scientific | 2006 |
| Andrew Consultancy Ltd | Administrative & support | 2015 |
| Andrew Dodd Consulting & Associates Limited | Professional & scientific | 2009 |
| Andrew Fleming Ltd | Construction | 2008 |
| Andrew Lawrence Entertainment Limited | Information & communication | 2012 |
| Andrew SIM Studio Ltd | Arts & recreation | 2023 |
| Andrews Home Improvements Ltd | Construction | 2014 |
| Andrews Hydrographics (Holding Company) Limited | Administrative & support | 2001 |
| Andrews Hydrographics Limited | Professional & scientific | 1978 |
| Anduity Limited | Financial services | 2022 |
| Andy MC Construction Ltd | Construction | 2018 |
| Andy Vans & Gardening Limited | Arts & recreation | 2002 |
| Andybobyta Ltd | Transport & logistics | 2023 |
| Anetos London Ltd | Wholesale & retail | 2023 |
| Anetyres Ltd | Wholesale & retail | 2024 |
| Angel & Rocket Limited | Wholesale & retail | 2014 |
| Angel Executive Travel Limited | Transport & logistics | 2019 |
| Angela Rigby Limited | Health & social care | 2016 |
| Angeleye Purchasing Limited | Health & social care | 2010 |
| Angledore Limited | Extraterritorial | 2016 |
| Anglia Eastern Logistics Limited | Wholesale & retail | 2021 |
| Anglo Irish Developments Limited | Real estate | 1999 |
| ANH Lucky Ltd | Other services | 2025 |
| Ania Sagajllo Ltd | Extraterritorial | 2022 |
| Anibesh UK Ltd | Wholesale & retail | 2025 |
| Anivra Technologies Limited | Information & communication | 2026 |
| Ankarmun Limited | Information & communication | 2016 |
| Ankika Ltd | Professional & scientific | 2023 |
| Ankur Consultants Ltd | Professional & scientific | 2022 |
| Anna Diamonds Bvba Ltd | Wholesale & retail | 2011 |
| Anna Hayward Ltd | Hospitality | 2025 |
| Anna Zofia Ltd | Extraterritorial | 2022 |
| Anna Zofia Sagajllo Ltd | Extraterritorial | 2022 |
| Annie Shah Makeup Limited | Other services | 2013 |