| Alternative Automotive Media Limited | Professional & scientific | 2015 |
| Altinok Construction Ltd | Construction | 2019 |
| Altraxx Plant Services Limited | Real estate | 2014 |
| Altree Ltd | Professional & scientific | 2021 |
| Aluc Trading Ltd | Wholesale & retail | 2021 |
| Alumdar 786 Ltd | Transport & logistics | 2019 |
| Alverstone Loft Conversions Limited | Construction | 2004 |
| Alvi Retail Ltd | Wholesale & retail | 2026 |
| Alvin CUT Barbers Limited | Other services | 2023 |
| Alway's COD Ltd | Hospitality | 2026 |
| Always Scaffolding Services Ltd | Construction | 2024 |
| Alyusra Books Ltd | Wholesale & retail | 2026 |
| AM Renovations Ltd | Construction | 2020 |
| AM Weaver Ltd | Construction | 2017 |
| Am&Se Trading Limited | Financial services | 2026 |
| AM06 Promotions Limited | Arts & recreation | 2025 |
| AM9 Promotions Ltd | Arts & recreation | 2022 |
| Amaan 8 Supermarket Ltd | Wholesale & retail | 2025 |
| Amada Resourcing Limited | Health & social care | 2023 |
| Aman Court Limited | Households | 1985 |
| Amanda Bolt Associates Limited | Professional & scientific | 2010 |
| Amanda Lacey Counselling Ltd | Health & social care | 2024 |
| Amani Care and Support Ltd | Real estate | 2018 |
| Amari Investment Holdings Limited | Real estate | 2020 |
| Amari Prestige Limited | Transport & logistics | 2020 |
| Amateur British Gymnastics Investments Limited | Financial services | 2019 |
| Amaya Construction (South Wales) Limited | Construction | 2019 |
| Amayce Limited | Manufacturing | 2024 |
| AMB Design & Consultancy Limited | Professional & scientific | 2022 |
| Amber Shield Finance Ltd | Financial services | 2024 |
| Ambientracks Ltd | Information & communication | 2025 |
| Ambishen Ltd | Real estate | 2023 |
| Ambulance IQ Ltd | Professional & scientific | 2025 |
| AMD Catering Limited | Hospitality | 2015 |
| AMD Property Sales Ltd | Real estate | 2020 |
| AMD Supplies Ltd | Wholesale & retail | 2016 |
| Amelia Court (Sandown) Management Company Limited | Extraterritorial | 2009 |
| AMG Welding Design Limited | Administrative & support | 2009 |
| AMH Facilities Limited | Administrative & support | 2016 |
| AMH Travel Ltd | Transport & logistics | 2026 |
| Amica Taberna Ltd | Other services | 2017 |
| Amity Planning Ltd | Professional & scientific | 2018 |
| Amma Enterprises Limited | Wholesale & retail | 2025 |
| Ammbro Technologies Limited | Manufacturing | 2014 |
| Ammonite Shipping Limited | Other services | 2026 |
| Ammro Consulting Limited | Construction | 2011 |
| Amms Constructions Ltd | Construction | 2024 |
| Ammô Animation Ltd | Information & communication | 2025 |
| AMN Management Limited | Hospitality | 2011 |
| Amoco Investments Ltd | Financial services | 2017 |
| Amos Hill Developments Limited | Wholesale & retail | 1957 |
| Amos Hill Holdings Limited | Financial services | 2020 |
| AMP Hire Ltd | Administrative & support | 2019 |
| AMP Training Solutions Ltd | Education | 2015 |
| Amped Motorcycles Ltd | Wholesale & retail | 2018 |
| Amperry Consulting Ltd | Information & communication | 2011 |
| Ample Finance Limited | Financial services | 2018 |
| Ample Healthcare Services Ltd | Administrative & support | 2023 |
| Ample Mortgages Limited | Financial services | 2020 |
| AMS Point Bodyshop Ltd | Wholesale & retail | 2026 |
| Amucha Limited | Wholesale & retail | 2010 |
| Amumbi's Health Care Ltd | Health & social care | 2016 |
| Amxvita Ltd | Professional & scientific | 2025 |
| AMY Robyn Beauty Ltd | Other services | 2024 |
| AMY Taylor Consulting Ltd | Professional & scientific | 2015 |
| AMZ Mart Ltd | Wholesale & retail | 2025 |
| Amzi Limited | Administrative & support | 2015 |
| AN Auto Services Limited | Wholesale & retail | 2021 |
| ANA Courier 786 Ltd | Transport & logistics | 2024 |
| Analogue & Micro Holdings Limited | Financial services | 2016 |
| Anastasia Art Ltd | Extraterritorial | 2024 |
| Anastrade Limited | Wholesale & retail | 2023 |
| Ancec Limited | Wholesale & retail | 2023 |
| Andando Ltd | Wholesale & retail | 2023 |
| Andrada Dent Ltd | Health & social care | 2023 |
| Andrew Baines Limited | Construction | 2014 |
| Andrew Grimstead Limited | Construction | 2014 |
| Andrew J Allsopp Ltd | Transport & logistics | 2018 |
| Andrew Roberts Consultancy Ltd | Administrative & support | 2017 |
| Andrew Wallis Limited | Administrative & support | 2013 |
| Andrew Williams Plumbing & Heating Ltd | Construction | 2024 |
| Andsara Limited | Construction | 2026 |
| Andy Glows Ltd | Health & social care | 2021 |
| Andy James Ltd | Arts & recreation | 2021 |
| Aneano Healthcare Limited | Health & social care | 2021 |
| Anergen LLP | | 2022 |
| Angel Grill IOW Ltd | Hospitality | 2024 |
| Angel Point Ltd | Professional & scientific | 2022 |
| Angela Taylor Designs Limited | Extraterritorial | 2009 |
| Angels Hotel Limited | Hospitality | 2020 |
| Angels Kitchen Limited | Hospitality | 2020 |
| Angels Restaurants Limited | Hospitality | 2020 |
| Anglo-Celtic Administration Ltd | Real estate | 2002 |
| Anglo-Celtic Financial Consultants Ltd | Financial services | 2006 |
| Angs Travel Ltd | Transport & logistics | 2025 |
| Anis Medicals Limited | Health & social care | 2022 |
| Anita Pascual Ltd | Health & social care | 2024 |
| Anita Walford OTC Limited | Health & social care | 2016 |
| Anivize Ltd | Manufacturing | 2024 |
| ANM FAB. Limited | Construction | 2016 |