| Afyne Ltd | Real estate | 2025 |
| Afzal Business Ltd | Wholesale & retail | 2024 |
| AG Block Paving Ltd | Administrative & support | 2021 |
| AG Family Ltd | Transport & logistics | 2025 |
| AG Fire Sprinklers Ltd | Public administration | 2018 |
| AG Growth Ltd | Real estate | 2020 |
| Agami Systems Limited | Information & communication | 2025 |
| Agatha's Space CIC | Health & social care | 2025 |
| AGB Tutoring Ltd | Education | 2018 |
| AGE UK Oldham Limited | Other services | 2010 |
| Agency Y Ltd | Information & communication | 2012 |
| AGENT27 Limited | Wholesale & retail | 2014 |
| AGF Holdings Limited | Real estate | 2022 |
| AGH Future Holdings Ltd | Real estate | 2019 |
| AGI Gigi Limited | Health & social care | 2017 |
| Agile Design & Build Limited | Construction | 2019 |
| Agile Finance Solutions Limited | Professional & scientific | 2025 |
| Agile Waze Limited | Information & communication | 2023 |
| Agkn Group Holdings Ltd | Financial services | 2026 |
| AGL Compliance UK Ltd. | Professional & scientific | 2016 |
| Agmar Contractors Ltd | Construction | 2015 |
| AGR Facilities Management Limited | Administrative & support | 2025 |
| AGR Scaffolds Ltd | Construction | 2025 |
| Agricultural and Equestrian Supplies Ltd | Administrative & support | 2017 |
| Agricultural Business Trading Company Ltd. | Wholesale & retail | 2023 |
| Agroecopower Limited | Information & communication | 2015 |
| Agroserv Ltd. | Administrative & support | 2013 |
| AGV Plastering Services Ltd | Construction | 2015 |
| AH Delivery MCR Ltd | Transport & logistics | 2022 |
| AH Inkaso Group Ltd | Financial services | 2022 |
| AH Self Storage Ltd | Transport & logistics | 2024 |
| Ahadecommerce Ltd | Wholesale & retail | 2026 |
| AHC Engineering & Site Services Ltd | Construction | 2011 |
| AHC Property Rentals Ltd | Real estate | 2025 |
| Ahern Property Management Limited | Real estate | 2018 |
| AHK Clothing Ltd | Wholesale & retail | 2025 |
| AHLOGISTICS2025 Ltd | Transport & logistics | 2025 |
| Ahmad and Saleem Ltd | Extraterritorial | 2014 |
| Ahmad and Saleem Partners Ltd | Health & social care | 2014 |
| Ahmad Enterprises Ltd | Wholesale & retail | 2024 |
| Ahmaduk Ltd | Wholesale & retail | 2023 |
| Ahmed Bros Wholesales Limited | Wholesale & retail | 2021 |
| Ahmed California Ltd | Hospitality | 2022 |
| Ahmedgroupnw Limited | Wholesale & retail | 2025 |
| Ahmeds Desserts Ltd | Hospitality | 2024 |
| Ahpg Ltd | Administrative & support | 2017 |
| Ahsan Trading UK Limited | Wholesale & retail | 2025 |
| AI Car Autos Ltd | Wholesale & retail | 2024 |
| AI Sourcing Technology Ltd | Wholesale & retail | 2021 |
| AI Super Group Limited | Professional & scientific | 2020 |
| AI Tutor Pro Ltd | Hospitality | 2025 |
| Aida Intelligent Solutions Limited | Administrative & support | 2020 |
| Aidel Smiles Ltd | Health & social care | 2016 |
| Aieouk Ltd | Administrative & support | 2026 |
| AIM High Enterprise C.I.C. | Education | 2014 |
| AIM Trades Corp Ltd | Wholesale & retail | 2023 |
| Aim&Mmr Ventures Ltd | Real estate | 2025 |
| Aimrel Technology Solutions Ltd | Administrative & support | 2025 |
| Aims Enterprises Ltd | Wholesale & retail | 2018 |
| Ainees Greenbox Limited | Manufacturing | 2021 |
| Air Conditioning Essentials Ltd | Construction | 2020 |
| Air Engineering Ltd | Manufacturing | 2009 |
| Air Engineering Services Ltd | Manufacturing | 2020 |
| Air Excellence Travels Ltd | Administrative & support | 2022 |
| Air Lines and Compressors Limited | Real estate | 1989 |
| Air Sampling Instruments Limited | Manufacturing | 2004 |
| Airnings Limited | Wholesale & retail | 2025 |
| Airtech Advanced Materials UK Ltd | Manufacturing | 1996 |
| Aisha Jewellers Limited | Wholesale & retail | 2013 |
| Aitch Conservation Ltd | Agriculture & fishing | 2016 |
| Aiza Boutique Ltd | Wholesale & retail | 2022 |
| Aizahs Collection Limited | Wholesale & retail | 2018 |
| AJ & MH Properties Ltd | Real estate | 2022 |
| AJ Group Cambridge Limited | Construction | 2022 |
| AJ Luxury Gifts Ltd | Wholesale & retail | 2024 |
| AJ Marsden Ltd | Construction | 2005 |
| AJ On-Site Solutions Ltd | Manufacturing | 2026 |
| AJ Plumbers Ltd | Construction | 2024 |
| AJ Scott Properties Ltd | Households | 2025 |
| AJ Star Oldham Limited | Other services | 2026 |
| AJA Properties (H) Ltd | Real estate | 2019 |
| AJB Facades UK Ltd | Construction | 2020 |
| AJC Frying Ltd | Hospitality | 2025 |
| AJC Utility Ltd | Construction | 2025 |
| AJD Property Limited | Real estate | 2016 |
| Ajdaviesbeers Ltd | Hospitality | 2025 |
| AJF Solutions Limited | Construction | 2007 |
| AJK Catering Limited | Hospitality | 2025 |
| AJK Group Ltd | Wholesale & retail | 2025 |
| AJK Secure Logic Ltd | Administrative & support | 2024 |
| AJK Transport Ltd | Transport & logistics | 2023 |
| AJM Brands Ltd | Manufacturing | 2025 |
| AJM Investors Limited | Real estate | 2018 |
| Ajmaths Ltd | Education | 2023 |
| AJS Social Care Limited | Information & communication | 2016 |
| AK & Co Services Ltd | Financial services | 2019 |
| AK & HH Ltd | Wholesale & retail | 2020 |
| AK Distillery Ltd | Manufacturing | 2024 |
| AK Estates MCR Ltd | Real estate | 2024 |
| AK Hospitality Services Limited | Hospitality | 2025 |