| After I AM Gone Limited | Information & communication | 2020 |
| AG Signature Smiles Limited | Health & social care | 2024 |
| AG9 Property Limited | Real estate | 2024 |
| AGA Projects Limited | Professional & scientific | 2008 |
| Agam Properties Private Limited | Real estate | 2021 |
| Agarwal Properties Limited | Real estate | 2017 |
| Agathian Ltd | Information & communication | 2024 |
| Aggregate Partners Group Ltd | Construction | 2016 |
| Aggregate Partners LLP | | 2015 |
| Agile Content Ltd | Professional & scientific | 2015 |
| Agile Projectech Ltd | Information & communication | 2024 |
| Agilearch Limited | Information & communication | 2012 |
| Agro Capital | | 1989 |
| AGS Seafood Limited | Agriculture & fishing | 2024 |
| AGV Property Holding Ltd. | Real estate | 2016 |
| Agwa Ltd | Hospitality | 2012 |
| AH Global Ventures Ltd | Education | 2025 |
| Ahana Ltd | Wholesale & retail | 2020 |
| Ahdia Ltd | Other services | 2021 |
| Ahlebait (UK) Ltd | Information & communication | 2011 |
| Ahlebait TV Limited | Information & communication | 2010 |
| Ahmet Bekir Limited | Information & communication | 2005 |
| Ahpjp Limited | Information & communication | 2014 |
| AHR Homes Ltd | Health & social care | 2020 |
| AHR Partners Limited | Wholesale & retail | 2025 |
| Ahre Capital Limited | Professional & scientific | 2026 |
| AHS Investments Ltd | Real estate | 2020 |
| Ahya Corp Ltd | Wholesale & retail | 2021 |
| Ahya Occupational Therapy Services Limited | Education | 2026 |
| Ahya Properties Ltd | Real estate | 2023 |
| AI Factory Limited | Information & communication | 2003 |
| AIA Security Ltd | Administrative & support | 2013 |
| Aidash UK Ltd | Information & communication | 2021 |
| Ailaca Limited | Professional & scientific | 2014 |
| AIM Ventures Ltd | Information & communication | 2010 |
| Aimtoheal Limited | Other services | 2025 |
| Air Quality Assessment & Policy Limited | Professional & scientific | 2014 |
| Air Web Solutions Limited | Information & communication | 2009 |
| Airemail Holdings Limited | Information & communication | 2020 |
| Airs Properties Limited | Real estate | 2025 |
| Aium Limited | Information & communication | 2026 |
| AJ & RA Ltd | Wholesale & retail | 2014 |
| AJ Bicknell Solutions Ltd | Professional & scientific | 2023 |
| AJ Fresh Fruits & Drinks Ltd | Hospitality | 2026 |
| AJ Home Solutions Ltd | Financial services | 2017 |
| AJ Lyon XP Ltd | Education | 2016 |
| AJB Enterprises Limited | Hospitality | 2013 |
| AJB Partnership LLP | | 2013 |
| AJE Real Estate Ltd | Real estate | 2023 |
| Ajfriel Limited | Professional & scientific | 2025 |
| Ajjs Properties Ltd | Real estate | 2020 |
| Ajkr Services Ltd | Professional & scientific | 2018 |
| AJP Real Estate Limited | Real estate | 2021 |
| AJP Trading Consultancy Ltd | Education | 2026 |
| AJP369 Limited | Real estate | 2020 |
| AJS Residential Ltd | Real estate | 2024 |
| Ajschat Ltd | Health & social care | 2024 |
| AJY Trading Co Ltd | Wholesale & retail | 2025 |
| AK Prestige Property Limited | Real estate | 2025 |
| AK Quality Management Limited | Information & communication | 2011 |
| AK Wealth Limited | Real estate | 2020 |
| AK Welling Limited | Real estate | 2024 |
| Akaberry (London) Limited | Real estate | 2009 |
| Akabo Media Ltd. | Professional & scientific | 2011 |
| Akbar Dermatology Limited | Health & social care | 2015 |
| Akdg Limited | Information & communication | 2022 |
| Akhi Retreats Ltd | Administrative & support | 2023 |
| Akhihood CIC | Arts & recreation | 2025 |
| Akimany Limited | Information & communication | 2008 |
| Akin Investments Limited | Construction | 2001 |
| Aksahin Management Limited | Hospitality | 2020 |
| Aksana Ltd | Financial services | 2015 |
| Aksb Limited | Real estate | 2023 |
| Akshar Asset Investments Limited | Financial services | 2025 |
| Akshar Mortgage Solutions Limited | Financial services | 2019 |
| AL - Mizan Charitable Trust | Health & social care | 2010 |
| AL Barakah Learning Ltd | Wholesale & retail | 2024 |
| AL Barakah School Limited | Education | 2018 |
| AL Cedar Co Ltd | Other services | 2013 |
| AL Forno Ltd | Hospitality | 2015 |
| AL Triangle UK Limited | Wholesale & retail | 2015 |
| Alan's Chicken Ltd | Hospitality | 2020 |
| Albany Appliance Centre Limited | Real estate | 1974 |
| Albaraka Cleaning Ltd | Administrative & support | 2025 |
| Albaraka Wash Ltd | Other services | 2017 |
| Alco Products (UK) Limited | Real estate | 1986 |
| Alconbury Holdings Ltd | Financial services | 2024 |
| Alconbury Medicines Limited | Wholesale & retail | 2018 |
| Alcoprop Limited | Real estate | 2013 |
| Aldc Limited | Construction | 2019 |
| Aletsi Site Solutions Limited | Construction | 2025 |
| Alex Afnan Consulting Ltd | Professional & scientific | 2000 |
| Alexander Medical Ltd | Health & social care | 2025 |
| Alexander RHC Ltd | Real estate | 2026 |
| Alexanders (UK) Limited | Professional & scientific | 2000 |
| Alexandra Road (Hornsey) Management Limited | Real estate | 2000 |
| Alexandra's Pizzeria & Grill House Ltd | Hospitality | 2024 |
| Alfie Solomons Limited | Wholesale & retail | 2025 |
| Algolink Limited | Information & communication | 2021 |
| Algri Services Limited | Construction | 2025 |