| AK23 Trading Ltd | Wholesale & retail | 2024 |
| AKA K9 Ltd | Agriculture & fishing | 2018 |
| Akca Development Ltd | Construction | 2023 |
| Akinfenwa Holding Company (AHC) Ltd | Financial services | 2025 |
| AKK Softtech UK Limited | Information & communication | 2022 |
| Aklima Properties Limited | Professional & scientific | 2024 |
| AKM Legacy Limited | Hospitality | 2026 |
| AKO KUM Ltd | Transport & logistics | 2021 |
| Akpinfotech Ltd | Information & communication | 2017 |
| Akroyd Rogers Consulting Limited | Professional & scientific | 2015 |
| Aksel Construction Ltd | Construction | 2023 |
| Aksi Anarkali Dunstable Ltd | Hospitality | 2023 |
| AL Falah Business Ltd | Construction | 2018 |
| AL Harwood Building Services Limited | Construction | 2016 |
| Al-Saleha Foundation | Other services | 2025 |
| Al-Samad Investments Limited | Real estate | 2018 |
| Al-Yasiri Capital Ltd | Real estate | 2025 |
| Alam Properties & Developments Limited | Construction | 2015 |
| Alban Car Body Repairs Ltd | Manufacturing | 2015 |
| Albans Way Limited | Transport & logistics | 2024 |
| Albedo Advisory Ltd | Professional & scientific | 2026 |
| Albert Green Limited | Hospitality | 2017 |
| Alberto 'S Kitchen Ltd | Hospitality | 2017 |
| Albion Trade UK Ltd | Extraterritorial | 2017 |
| Alden Ventilation Limited | Construction | 2018 |
| Aldgate Properties Limited | Real estate | 1981 |
| Aled Construction Limited | Construction | 2022 |
| Aleksandra Properties Ltd | Real estate | 2025 |
| Aleniam Limited | Real estate | 2017 |
| Alex Builder 72 Limited | Construction | 2022 |
| Alex Ellis Design Limited | Professional & scientific | 2019 |
| Alex Solley Racing Ltd | Wholesale & retail | 2021 |
| Alexander & Elai Ltd | Construction | 2022 |
| Alexandru&Dia Trans Ltd | Other services | 2019 |
| Aley Green Management Company Limited | Real estate | 2001 |
| Alfa Associates Limited | Professional & scientific | 2019 |
| Alfaparts Limited | Wholesale & retail | 2010 |
| Alhpa Investibles Ltd | Wholesale & retail | 2020 |
| ALI Auto Repair Ltd | Wholesale & retail | 2020 |
| Aliceco Ltd | Construction | 2026 |
| Alim Transport Limited | Transport & logistics | 2017 |
| Alison RAY Dance Company Ltd | Arts & recreation | 2017 |
| Alistair Bennett Associates Ltd | Information & communication | 2009 |
| Alitrans Ltd | Transport & logistics | 2026 |
| ALL - in House Ltd | Real estate | 2020 |
| ALL ALL Ltd | Transport & logistics | 2022 |
| ALL Clean Solutions Limited | Administrative & support | 2019 |
| ALL Drone Services Limited | Professional & scientific | 2018 |
| ALL Events Limited | Wholesale & retail | 2008 |
| ALL GAS Solutions Bucks Limited | Construction | 2021 |
| ALL Saints Academy Dunstable | Education | 2009 |
| ALL Styles Landscapes Limited | Administrative & support | 2025 |
| ALL Things Accounted 4 Ltd | Wholesale & retail | 2024 |
| ALL Trees & Hedges Ltd | Other services | 2018 |
| Allaround Renovation Ltd | Construction | 2020 |
| ALLBAR1 Ltd | Hospitality | 2023 |
| Allbarco Ltd | Hospitality | 2022 |
| Allcraft Limited | Construction | 2004 |
| Alliance Visual Group Ltd. | Extraterritorial | 2024 |
| Allied Associates (Geophysical) Limited | Professional & scientific | 1988 |
| Allion Ltd | Information & communication | 2025 |
| Allpan Ltd | Construction | 2010 |
| Allpile Group Ltd | Construction | 2020 |
| Allplant Hire Limited | Extraterritorial | 1995 |
| Allure Aesthetics by SK Ltd | Other services | 2024 |
| Allwood Carpentry and Joinery Ltd | Manufacturing | 2018 |
| Almaoak Limited | Professional & scientific | 1995 |
| Almighty K9 Ltd | Administrative & support | 2026 |
| Aloedivina Ltd | Wholesale & retail | 2025 |
| Alpha 1 Trades Ltd | Construction | 2015 |
| Alpha Auto Bodyworks Ltd | Wholesale & retail | 2025 |
| Alpha Express Limited | Hospitality | 2025 |
| Alpha Omicron Limited | Information & communication | 2016 |
| Alpha Upholstery Limited | Other services | 2003 |
| Alphabets Group Limited | Wholesale & retail | 2021 |
| Alphacore Enterprises Ltd | Wholesale & retail | 2024 |
| Alphatec Marketing Limited | Professional & scientific | 2024 |
| ALR Electrical Limited | Construction | 2018 |
| ALS Security Systems Ltd | Administrative & support | 2022 |
| Alternative Films Limited | Information & communication | 2023 |
| Altoma Properties Ltd | Real estate | 2024 |
| Aluclad Ltd | Construction | 2025 |
| Alvi Enterprises Limited | Wholesale & retail | 2017 |
| Alwalton Builders Limited | Construction | 2022 |
| Alyyon Spraying Ltd | Construction | 2024 |
| AM Building Contractors Aomt Limited | Construction | 2014 |
| AM Executive Travel Limited | Transport & logistics | 2023 |
| AM Fast Building Ltd | Construction | 2023 |
| AM Sweeps Stoves & Fireplaces Limited | Construction | 2015 |
| Amaan Trading Limited | Wholesale & retail | 2023 |
| Amadeus Electrics Ltd | Construction | 2007 |
| Amal's Care Ltd | Wholesale & retail | 2026 |
| Amana Online Ltd | Wholesale & retail | 2025 |
| Amanda Rockley Esmt Limited | Other services | 2019 |
| Amaya Properties MK Limited | Construction | 2018 |
| Amazing GOD Ltd | Wholesale & retail | 2023 |
| Amazon Studios Limited | Professional & scientific | 2014 |
| Amazonite Limited | Wholesale & retail | 2021 |
| AMBAR2GROUP Limited | Information & communication | 2017 |
| AMBAR2PROPERTY Limited | Real estate | 2018 |