| AIMS2 Petrogrocs Ltd | Wholesale & retail | 2014 |
| Aina Properties Limited | Real estate | 2003 |
| Ainko Limited | Wholesale & retail | 2025 |
| Ainscough Motor Group Ltd | Wholesale & retail | 2016 |
| Ainsworth Clothing Company Ltd | Wholesale & retail | 2019 |
| Ainsworth Estates Ltd | Construction | 2013 |
| Ainsworth Projects Ltd | Construction | 2014 |
| AIO Tech Solutions Ltd | Wholesale & retail | 2024 |
| Aionios Group Ltd | Financial services | 2025 |
| Aionis Ventures Limited | Professional & scientific | 2026 |
| AIQ Global Ltd | Wholesale & retail | 2024 |
| Air and Isla Ltd | Professional & scientific | 2025 |
| Air Conditioning World Limited | Energy | 2025 |
| Air Gymwear Ltd | Wholesale & retail | 2018 |
| Air-Demand-Pneumatics Ltd | Manufacturing | 2025 |
| Air-Qual Limited | Construction | 2006 |
| AIR2O Cooling Limited | Manufacturing | 2014 |
| Airburo Limited | Information & communication | 2015 |
| Airdigz Ltd | Real estate | 2024 |
| Airfields Limited | Construction | 2026 |
| Airie NW Limited | Wholesale & retail | 2023 |
| Airmaxx Events Limited | Arts & recreation | 2019 |
| Airoma Noir Ltd | Wholesale & retail | 2025 |
| Airspace Lighting Ltd | Manufacturing | 2025 |
| Airstream Limited | Transport & logistics | 2015 |
| Aish Group-Uk Ltd | Manufacturing | 2022 |
| Aishmany LLP | | 2013 |
| Aitchison Consulting Ltd | Professional & scientific | 2024 |
| AIU Group Ltd | Financial services | 2024 |
| Aivb Ltd | Wholesale & retail | 2024 |
| Aivrsoft Limited | Information & communication | 2024 |
| AIY Limited | Real estate | 2017 |
| AJ Apex Ltd | Wholesale & retail | 2026 |
| AJ Appliances Avenue Ltd | Wholesale & retail | 2024 |
| AJ Digital Consultancy Ltd | Real estate | 2023 |
| AJ Kharal Ltd | Transport & logistics | 2023 |
| AJ Pharma Limited | Health & social care | 2014 |
| AJ Phoenix Limited | Hospitality | 2024 |
| AJ Property Developers Limited | Real estate | 2025 |
| AJ Skin & Body Clinic Ltd | Health & social care | 2026 |
| AJ Studio Kids Clothing Ltd | Wholesale & retail | 2024 |
| AJ Trade Group Ltd | Wholesale & retail | 2022 |
| Aj's Distribution Services Ltd | Other services | 2022 |
| AJA Assets Ltd | Construction | 2024 |
| AJA Consulting Services Ltd | Professional & scientific | 2025 |
| Ajax Capital Partners Limited | Professional & scientific | 2024 |
| Ajax Equipment Holdings Limited | Manufacturing | 2003 |
| Ajax Equipment Limited | Manufacturing | 1970 |
| AJC Commercial Properties Ltd | Real estate | 2015 |
| AJC Lincs Ltd | Professional & scientific | 2024 |
| AJE Transport Ltd | Transport & logistics | 2025 |
| AJF Commercial Ltd | Professional & scientific | 2017 |
| AJF Railway Ltd | Administrative & support | 2026 |
| AJH Building & Property Ltd | Extraterritorial | 2024 |
| AJH Financial Accountants Limited | Professional & scientific | 2015 |
| AJK Property Rentals Limited | Households | 2026 |
| AJM Developments Limited | Information & communication | 2016 |
| AJM Transport (Durham) Limited | Transport & logistics | 2021 |
| Ajos Group Ltd | Administrative & support | 2020 |
| AJP Handyman Ltd | Construction | 2025 |
| AJP Heating Solutions Ltd | Energy | 2026 |
| AJP Hire & Sales Ltd | Administrative & support | 2023 |
| AJP Logistics Ltd | Transport & logistics | 2010 |
| AJP Storage Limited | Extraterritorial | 2025 |
| AJR Building Contractors Limited | Construction | 2025 |
| AJS Aesthetics Ltd | Professional & scientific | 2022 |
| AJS Setting OUT Services Ltd | Professional & scientific | 2024 |
| AJS Sourcing Limited | Manufacturing | 2015 |
| AJT Bathrooms & Plumbing Ltd | Construction | 2022 |
| Ajvani Holdings Limited | Financial services | 2022 |
| Ajvani Investments Limited | Financial services | 2018 |
| Ajvani Shoes Limited | Wholesale & retail | 2002 |
| AJW Plumbing & Heating Ltd | Construction | 2019 |
| AJW89 Holdings Limited | Financial services | 2025 |
| Ajwa Ahmed Food Limited | Hospitality | 2025 |
| Ajwad International Limited | Wholesale & retail | 2025 |
| Ajwani Surgical Limited | Health & social care | 2024 |
| Ajwt Ltd | Administrative & support | 2023 |
| AJX Ltd | Other services | 2012 |
| AK & RK Trading Ltd | Hospitality | 2021 |
| AK 24/7 Ltd | Administrative & support | 2014 |
| AK Audiology Services Limited | Health & social care | 2025 |
| AK Autotech Limited | Wholesale & retail | 2013 |
| AK Cafe Limited | Hospitality | 2016 |
| AK Celestial UK Limited | Professional & scientific | 2012 |
| AK Connections Ltd | Information & communication | 2005 |
| AK Global Services Limited | Health & social care | 2019 |
| AK Grocers Ltd | Wholesale & retail | 2016 |
| AK Gundog Accessories Ltd | Other services | 2022 |
| AK Kirpa Property Limited | Real estate | 2025 |
| AK Lighting & Heating Limited | Wholesale & retail | 2020 |
| AK Motors & Logistics Ltd | Wholesale & retail | 2016 |
| AK Pahade Limited | Real estate | 2015 |
| AK Prime Move Limited | Wholesale & retail | 2026 |
| AK Properties Manchester Ltd | Real estate | 2024 |
| AK Sofamous Ltd | Hospitality | 2024 |
| AK1 Services Limited | Education | 2023 |
| AKA Turk Construction Limited | Construction | 2026 |
| Akan Tech Recruitment Limited | Administrative & support | 2019 |
| Akan Technical Training Centre Ltd. | Education | 2018 |