| Aired Ltd | Information & communication | 2017 |
| Airflow Design Services Limited | Construction | 2012 |
| Airotech R & D Ltd | Professional & scientific | 2025 |
| Airport Direct Cars Ltd | Transport & logistics | 2016 |
| Airport Links Taxis Ltd | Transport & logistics | 2021 |
| Airports Worldwide UK Holding Limited | Transport & logistics | 2013 |
| Airspace Estates Ltd | Real estate | 2020 |
| Airtravelservicepvt Ltd | Administrative & support | 2025 |
| Aiscon Ltd | Construction | 2026 |
| Aisio Property Ltd | Real estate | 2025 |
| Aisk Ltd | Professional & scientific | 2026 |
| Aitch Demolition Co. Ltd | Construction | 2001 |
| Aitch Plant and Equipment Limited | Water & waste | 2012 |
| Aizaan Trading Ltd | Wholesale & retail | 2020 |
| AJ Dynamic Construction Ltd | Construction | 2025 |
| AJ Mcginley Property Ltd | Real estate | 2019 |
| AJ Mcginley Renovations Ltd | Construction | 2026 |
| AJ Mortgages Ltd | Financial services | 2022 |
| AJ Property Capital Ltd | Real estate | 2026 |
| AJ Van Hire Limited | Administrative & support | 2021 |
| AJ3 Investments Limited | Real estate | 2023 |
| Ajab and Ajab Property Limited | Real estate | 2015 |
| Ajang Ltd | Information & communication | 2025 |
| Ajax Real Estates Limited | Real estate | 2025 |
| Ajazi Construction Ltd | Construction | 2021 |
| AJC Electrical LLP | | 2008 |
| AJE Facades Limited | Construction | 2012 |
| Ajeka Consulting Limited | Professional & scientific | 2018 |
| Ajet Engineering Consultancy Limited | Energy | 2019 |
| AJK Services Group Limited | Extraterritorial | 2016 |
| AJL Accountancy Limited | Professional & scientific | 2017 |
| AJM Design and Build Ltd | Construction | 2010 |
| AJM Electrical Contractors Ltd | Other services | 2018 |
| AJM Reviews Ltd | Professional & scientific | 2021 |
| Ajmera Limited | Professional & scientific | 2016 |
| Ajonmax Holdings Ltd | Financial services | 2026 |
| AJP Analysis Ltd | Professional & scientific | 2023 |
| AJR Consulting Engineers Ltd | Professional & scientific | 2018 |
| AJR Foods Ltd | Hospitality | 2025 |
| AJS Works PVT Limited | Transport & logistics | 2025 |
| AJT Business Transformation Ltd | Professional & scientific | 2023 |
| AJT Site Services Ltd | Professional & scientific | 2016 |
| AK & Co Builders Ltd | Construction | 2025 |
| AK Accountants Ltd | Professional & scientific | 2002 |
| AK Chippy Ltd | Hospitality | 2025 |
| AK Cutler Heights Ltd | Real estate | 2022 |
| AK Integration Ltd | Information & communication | 2005 |
| AK IT Consulting Limited | Information & communication | 2015 |
| AK Midlands Wholesale Ltd | Wholesale & retail | 2021 |
| AK Travel Watford Ltd | Transport & logistics | 2025 |
| AK13 Traders Ltd | Wholesale & retail | 2024 |
| AK9C Walking With Trudi Ltd | Education | 2020 |
| AKA Grill Ltd | Hospitality | 2025 |
| Akan Ventures Limited | Real estate | 2026 |
| AKB Studios Limited | Education | 2024 |
| AKB Technical Services Limited | Professional & scientific | 2024 |
| Akbh-Csft Ltd | Information & communication | 2016 |
| Akem Investments UK Ltd | Real estate | 2016 |
| Akerus Company Ltd | Administrative & support | 2010 |
| Akhiy Ltd | Professional & scientific | 2022 |
| Akhtar-Shahzad Ltd | Real estate | 2021 |
| Akinita Limited | Real estate | 2017 |
| Akiron PVT Ltd | Wholesale & retail | 2024 |
| Akita Brands Limited | Professional & scientific | 2016 |
| Akkalareddy Limited | Information & communication | 2022 |
| AKL Line Limited | Transport & logistics | 2015 |
| AKM Cafe Ltd | Hospitality | 2019 |
| AKM Lawyers Limited | Professional & scientific | 2023 |
| Akram Alam Ltd | Professional & scientific | 2012 |
| AKS Flooring & Furniture Limited | Construction | 2022 |
| AKS Services Group Limited | Mining & quarrying | 2017 |
| Aksent Limited | Professional & scientific | 2016 |
| Aksha Technologies Ltd | Information & communication | 2012 |
| Akshar Builders Ltd | Construction | 2019 |
| Akshar Business Consulting Ltd | Information & communication | 2018 |
| Akshar Health Care Limited | Health & social care | 2007 |
| Akshar Tech Consultants Ltd | Information & communication | 2025 |
| Aksharam Ltd | Wholesale & retail | 2022 |
| Akshaya Patra U.K. Limited | Hospitality | 2020 |
| Akss IT Solutions Limited | Information & communication | 2012 |
| AKT Physiotherapy Limited | Health & social care | 2024 |
| Aktv Limited | Professional & scientific | 2016 |
| AKU Shika Ltd | Professional & scientific | 2022 |
| Akut- Hona Health Ltd | Health & social care | 2021 |
| AKY Consulting Ltd | Professional & scientific | 2018 |
| AL Carim Ltd | Real estate | 2015 |
| AL Daee Enterprises Limited | Professional & scientific | 2012 |
| AL Ghazi Limited | Construction | 2001 |
| AL Interior Design Ltd | Professional & scientific | 2024 |
| AL Investment Holdings Limited | Financial services | 2025 |
| AL Property Consultants Ltd | Professional & scientific | 2024 |
| AL Rehman Ltd | Wholesale & retail | 2019 |
| Al-Alio Care Ltd | Health & social care | 2024 |
| Al-Barazi London Holdings Limited | Professional & scientific | 2019 |
| Al-Husam Limited | Real estate | 2024 |
| Al-Id London Ltd | Professional & scientific | 2026 |
| AL1 Change Ltd | Professional & scientific | 2015 |
| Aladdin Body Repairs Limited | Wholesale & retail | 1999 |
| Alain Engineering Services Ltd | Professional & scientific | 2023 |
| Alam Bookkeeping Limited | Professional & scientific | 2023 |