| Avenue Capital Limited | Real estate | 2020 |
| Avenue Gardens Property Company Ltd | Real estate | 2020 |
| Avery Heights Ltd | Health & social care | 2026 |
| Avesta Consulting Ltd | Professional & scientific | 2024 |
| AVI Fixing Limited | Construction | 2021 |
| AVI Projects Ltd | Professional & scientific | 2026 |
| Avida Go Limited | Hospitality | 2017 |
| Avina Properties Limited | Real estate | 2021 |
| Avoca Healthcare Ltd | Professional & scientific | 2018 |
| Avocadium Cakes and Pastries Ltd | Hospitality | 2024 |
| Avocadium Catering Ltd | Hospitality | 2024 |
| Avocadium Delirium Ltd | Hospitality | 2023 |
| Avoude Ltd | Manufacturing | 2025 |
| AVS Advisory Ltd | Information & communication | 2026 |
| AWA Studio Ltd | Other services | 2026 |
| AWC 2020 Ltd | Construction | 2022 |
| Awesomebly Ltd | Administrative & support | 2025 |
| AX Gadget Repairs Limited | Wholesale & retail | 2025 |
| AX(1) Gadgets Repairs Limited | Wholesale & retail | 2025 |
| Axiomatiq Ltd | Information & communication | 2025 |
| AY & EP Limited | Hospitality | 2010 |
| Aykut Cafes Limited | Hospitality | 2015 |
| Aylin Altay Cello Ltd | Education | 2025 |
| Ayres and Sons Limited | Construction | 2015 |
| B Jeon Ltd | Hospitality | 2024 |
| B.J Roofing and Construction Ltd | Construction | 2025 |
| B2K Catering Ltd | Hospitality | 2022 |
| B93 Media Ltd | Information & communication | 2018 |
| Baba Love.London Ltd | Hospitality | 2020 |
| Bacuri Consultancy & Training Ltd | Professional & scientific | 2017 |
| Baek Ltd | Other services | 2022 |
| Baemax Advisory Limited | Information & communication | 2026 |
| BAF Bioanalytics Ltd | Professional & scientific | 2025 |
| Bagillion Limited | Wholesale & retail | 2026 |
| Baitul Ltd | Real estate | 2025 |
| Baleno London Ltd | Wholesale & retail | 2019 |
| Ball Associates Ltd | Professional & scientific | 2002 |
| Balmant Contractors Ltd | Construction | 2025 |
| Banh BAO Brothers Limited | Hospitality | 2017 |
| Banjum London Ltd | Hospitality | 2024 |
| BAP & BAP Ltd | Hospitality | 2024 |
| Bapoocch Begard Ltd | Wholesale & retail | 2019 |
| Barnett Land Co Ltd | Construction | 2024 |
| Baroness Parlour Ltd | Other services | 2025 |
| Barwick Consulting Solutions Limited | Professional & scientific | 2025 |
| Base Logic Ltd | Manufacturing | 2011 |
| Base Manage Ltd | Construction | 2013 |
| Bashah Traders Ltd | Wholesale & retail | 2022 |
| Basing Residents Association Limited | Administrative & support | 1958 |
| Baxi Software Ltd | Information & communication | 2025 |
| Baytree Labs Ltd | Information & communication | 1998 |
| Baytree Media Group Limited | Financial services | 2017 |
| BC Consult Solutions Limited | Professional & scientific | 2011 |
| Bdba Ltd | Wholesale & retail | 2020 |
| BE Kind Studios Ltd | Information & communication | 2023 |
| Beacon CH Ltd | Health & social care | 2025 |
| Beangeist Ltd | Administrative & support | 2017 |
| Beaton House Concierge Ltd | Hospitality | 2026 |
| Beautiful Church London | Other services | 2016 |
| Beddle Limited | Wholesale & retail | 2024 |
| Beiji International Trade Co., Ltd | Wholesale & retail | 2025 |
| Beili Consultancy Limited | Other services | 2015 |
| Being Physis Ltd | Wholesale & retail | 2022 |
| Being Spirit Limited | Information & communication | 2019 |
| Beka Ltd | Hospitality | 2020 |
| Bella Business Solutions Ltd | Information & communication | 2026 |
| Belli Property Developments Ltd | Construction | 2019 |
| Bembridge (FOX) Consulting Ltd | Professional & scientific | 2024 |
| Bench Blisters Rowing Club Limited | Arts & recreation | 2018 |
| Benjamin.Co.Uk London Ltd | Wholesale & retail | 2019 |
| Beresford Court (New Malden) RTM Company Limited | Households | 2019 |
| Berichca Limited | Health & social care | 2010 |
| Berwick Court (Worcester Park) Residents Association Limited | Real estate | 1968 |
| Bessie Diputado Ltd | Extraterritorial | 2024 |
| Best Beauty Clinic Ltd | Other services | 2026 |
| Best Group Holdings (UK) Inc Ltd | Professional & scientific | 2021 |
| Best TSP Ltd | Wholesale & retail | 2026 |
| Bestec Co. Ltd. | Administrative & support | 2006 |
| Bester Trading Co., Ltd | Wholesale & retail | 2010 |
| Bestlake Limited | Real estate | 2017 |
| Beta 18 Solutions Ltd | Professional & scientific | 2023 |
| Beta Outcomes Limited | Professional & scientific | 2016 |
| Beth Arogbonlo Ltd | Wholesale & retail | 2025 |
| Betsutenjin Sutton Company Limited | Hospitality | 2025 |
| Better Access Platforms Ltd | Construction | 2021 |
| Better Homes Estates Limited | Real estate | 2024 |
| Bevan.Ai Ltd | Information & communication | 2024 |
| Beyond Heating and Plumbing Limited | Professional & scientific | 2020 |
| Beyroots Ltd. | Hospitality | 2017 |
| BFB Creations Ltd | Wholesale & retail | 2025 |
| BFM Production Services Limited | Information & communication | 2017 |
| Bgram Limited | Real estate | 2026 |
| Bharat Technology Limited | Manufacturing | 2025 |
| BHT Ltd | Information & communication | 2015 |
| BI WON Limited | Hospitality | 2009 |
| Bibijang Ltd | Hospitality | 2018 |
| Big Sam's Chicken and Grill Ltd | Hospitality | 2024 |
| Big Shoes Ltd | Professional & scientific | 2016 |
| Big Wave Films Ltd | Information & communication | 2021 |
| Bigtube Limited | Information & communication | 2024 |