| Autogrand Motors Limited | Wholesale & retail | 2023 |
| Autolab Worx Ltd | Wholesale & retail | 2025 |
| Automobile Lock Services Ltd | Other services | 2012 |
| Automotive Gurus Limited | Wholesale & retail | 2021 |
| Autonomy One Ltd | Professional & scientific | 2018 |
| Autoporsheworx Ltd | Wholesale & retail | 2022 |
| Autumn House Care Limited | Health & social care | 2010 |
| Auxilium Prestige Limited | Wholesale & retail | 2024 |
| AV Fitness Limited | Other services | 2013 |
| AVA Constructions Limited | Construction | 2016 |
| AVA Smart Fashion Limited | Other services | 2013 |
| Avalon Garden & Design Ltd | Professional & scientific | 2023 |
| Avalon Properties & Services Limited | Households | 2014 |
| Avalon Transport Limited | Transport & logistics | 2025 |
| Avancia Solutions Ltd | Information & communication | 2025 |
| Avant-Garde Blue Limited | Construction | 2018 |
| Avatara Inc Ltd | Financial services | 2018 |
| Avayo Europe Limited | Wholesale & retail | 2024 |
| AVD Portfolio Ltd | Financial services | 2020 |
| Avenell & Collier Ltd | Wholesale & retail | 2025 |
| Avenue in London Limited | Real estate | 2016 |
| Avenue Investments Limited | Construction | 1954 |
| Aviaf Asset Management Limited | Real estate | 2018 |
| Avisoft Solutions Limited | Information & communication | 2014 |
| Avital Limited | Construction | 2016 |
| Avivys UK Limited | Information & communication | 2024 |
| AVO Catering Company Limited | Construction | 1974 |
| Avon Investments Limited | Real estate | 2013 |
| Avon Lake Holdings Limited | Real estate | 2015 |
| Avon Management (UK) Limited | Real estate | 2005 |
| Avrupa Properties Ltd | Real estate | 1999 |
| Avss Electrical Ltd | Construction | 2026 |
| Avvelo Limited | Extraterritorial | 2019 |
| Avxhi Limited | Information & communication | 2025 |
| Avzin Ltd | Real estate | 2025 |
| Awakened Somatics Limited | Health & social care | 2009 |
| Awav Support Ltd | Professional & scientific | 2025 |
| Awesome Restaurants Limited | Administrative & support | 2016 |
| AWG Consulting Ltd | Information & communication | 2025 |
| AX Build & Restore Limited | Construction | 2022 |
| AXE ARB Limited | Agriculture & fishing | 2023 |
| Axiom Estates Ltd | Real estate | 2025 |
| Axiom Horizon Limited | Wholesale & retail | 2024 |
| Axis Software Limited | Information & communication | 2024 |
| Ayanasia Limited | Real estate | 2008 |
| Ayani Limited | Real estate | 2022 |
| AYH Group Ltd | Administrative & support | 2025 |
| Ayimkan Limited | Information & communication | 2015 |
| Aylesbury Contracts Limited | Real estate | 2023 |
| Aylesham Barbers Ltd | Other services | 2018 |
| Ayniry Ltd | Administrative & support | 2011 |
| Ayra IT Solutions Limited | Information & communication | 2022 |
| Ayrin Limited | Hospitality | 2026 |
| AZ Home Constructions Ltd | Construction | 2022 |
| AZ Lease Management Limited | Real estate | 2015 |
| AZ Studios Limited | Wholesale & retail | 2020 |
| Azar Consulting Ltd. | Professional & scientific | 2014 |
| Azen Investments Ltd | Real estate | 2019 |
| AZM Groundworks Limited | Construction | 2017 |
| Azra Services Ltd | Hospitality | 2023 |
| B & F Plumbing & Heating Limited | Construction | 2012 |
| B & M Takeaways Limited | Hospitality | 2005 |
| B & N Removals Limited | Transport & logistics | 2024 |
| B and L Housing and Development Ltd | Real estate | 2024 |
| B and R Auto Electric Ltd | Real estate | 2021 |
| B and YOU Ltd | Wholesale & retail | 2020 |
| B Cota Constructions Ltd | Construction | 2022 |
| B D Consultants Ltd | Professional & scientific | 2014 |
| B Diverse Ltd | Professional & scientific | 2018 |
| B F Design Solutions Limited | Real estate | 2011 |
| B Mugabe Limited | Health & social care | 2010 |
| B Squared Software Development Ltd | Information & communication | 2026 |
| B&M Coopers Limited | Wholesale & retail | 2017 |
| B&S Services Ltd | Construction | 2021 |
| B. Eco Source Ltd | Construction | 2016 |
| B.B. Healthcare Limited | Health & social care | 2012 |
| B.C. Team Ltd | Construction | 2018 |
| B.I.R.(Properties)Limited | Real estate | 1961 |
| B.O.P. Productions Limited | Arts & recreation | 1996 |
| B2B SPV Ltd | Professional & scientific | 2020 |
| B3 Investments Limited | Other services | 2020 |
| B360 Residential Limited | Real estate | 2019 |
| BAC Law Limited | Professional & scientific | 2020 |
| Bacchus Places Limited | Real estate | 2020 |
| Back Heathrow Limited | Administrative & support | 2013 |
| Back to Back Chiropractic Ltd | Health & social care | 2004 |
| Backbone Post Ltd | Professional & scientific | 2026 |
| Badusindianfeast Ltd | Hospitality | 2018 |
| BAG IT London Ltd | Other services | 2025 |
| Bagman and Robin Ltd | Manufacturing | 2004 |
| Bailamo Medical Ltd | Health & social care | 2019 |
| Baird Engineering Services Ltd | Professional & scientific | 2014 |
| Bake'Emmmm Limited | Wholesale & retail | 2025 |
| Balance 22 Ltd | Professional & scientific | 2022 |
| Balbis Limited | Financial services | 2019 |
| Baller Collective Ltd | Arts & recreation | 2024 |
| Baller CUP Ltd | Arts & recreation | 2026 |
| Ballmi Construction Group Ltd | Construction | 2025 |
| Balmore Crescent RTM Company Limited | Households | 2006 |
| Balogun Dermatology Ltd | Health & social care | 2022 |