| Avtodor Limited | Construction | 2023 |
| Axim Energy Limited | Energy | 2011 |
| Axim Finance Limited | Construction | 2022 |
| Axis Story Limited | Information & communication | 2023 |
| AXO Motor Group Ltd | Wholesale & retail | 2026 |
| Axon VT Limited | Manufacturing | 2023 |
| Ayaan Building Services Limited | Construction | 2024 |
| Aydin Four Ltd | Real estate | 2021 |
| Ayob Gafuro Limited | Transport & logistics | 2011 |
| AZ Securities Limited | Transport & logistics | 2013 |
| Azeemi Homes Limited | Real estate | 2025 |
| Azis Holdings Limited | Real estate | 2021 |
| AZM Associates Limited | Real estate | 2019 |
| Azura Real Estate Ltd | Real estate | 2025 |
| B Treatments Ltd | Other services | 2019 |
| B&A Projects Ltd | Professional & scientific | 2023 |
| B&M Construction Services Ltd | Construction | 2022 |
| B. D. 2000 Limited | Manufacturing | 1999 |
| B.A.D. Properties Limited | Real estate | 1999 |
| B4RMA Limited | Health & social care | 2023 |
| Baabaa Coding Limited | Information & communication | 2024 |
| BAB Interior Fit Ltd | Construction | 2023 |
| BACK-2-NATURE Bodycare Health & Wellness Limited | Wholesale & retail | 2015 |
| Bafa Construction Ltd | Construction | 2014 |
| Bafa Grays Ltd | Construction | 2023 |
| Bafa Hillingdon Development Ltd | Real estate | 2018 |
| Bafa Orpington Development Ltd | Real estate | 2017 |
| Baldeep Motor Upgrades Ltd | Wholesale & retail | 2025 |
| Balister Ltd | Extraterritorial | 2016 |
| Ballister Ltd | Extraterritorial | 2016 |
| Banbury Properties Limited | Real estate | 2001 |
| Bantry Developments Limited | Real estate | 2020 |
| Bara Accounts Ltd | Professional & scientific | 2025 |
| Barakaa Limited | Administrative & support | 2018 |
| Barakah Edmonton Ltd | Real estate | 2025 |
| Barbod Distributer Limited | Wholesale & retail | 2026 |
| Bardhi Construction Ltd | Other services | 2018 |
| Bargain Hunter Private Limited | Wholesale & retail | 2018 |
| Bark Life Pet Care Services Limited | Other services | 2019 |
| Bark Life UK Walking Ltd | Other services | 2022 |
| Baron Property Ltd. | Real estate | 2017 |
| Barpol Limited | Hospitality | 2004 |
| Bars of Light CIC | Education | 2025 |
| Bass Optics Ltd | Health & social care | 2023 |
| Bathroom Heating & Plumbing Limited | Wholesale & retail | 2008 |
| Bathrooms Only Ltd | Construction | 2024 |
| Battlement Holdings Ltd | Real estate | 2018 |
| Battlement Properties Ltd | Real estate | 2018 |
| BC Health Solutions Ltd | Health & social care | 2014 |
| BC Solution Consultants Limited | Information & communication | 2024 |
| Beast Fight Team Ltd | Education | 2021 |
| Beauchamp Designs Limited | Professional & scientific | 2007 |
| Beautiful Wedding Favours Ltd | Arts & recreation | 2010 |
| Beez Home Ltd | Real estate | 2019 |
| Beijing House Gold Ltd | Hospitality | 2023 |
| BEL Capital Limited | Extraterritorial | 2013 |
| Belgravia Chauffeurs Ltd | Transport & logistics | 2016 |
| Bell & Preece Investments Limited | Construction | 1965 |
| Bella & JEN Ltd | Hospitality | 2024 |
| Bellevue Investments Limited | Real estate | 2017 |
| Bellpark Developments Limited | Construction | 2000 |
| Bellpark Holdings Ltd | Financial services | 2025 |
| BEM Construction Ltd | Construction | 2025 |
| Benext Football Limited | Arts & recreation | 2022 |
| Berkdar Investment Ltd | Wholesale & retail | 2022 |
| Bermondsey Property Holdings Limited | Real estate | 2019 |
| Berwyn Services Limited | Real estate | 2023 |
| Beryl Evetts and Robert Luff Animal Welfare Trust Limited(The) | Health & social care | 1981 |
| Beski Womens Care Limited | Health & social care | 2006 |
| Bespoke Kitchen & Bedroom Company Ltd | Manufacturing | 2017 |
| Best Coal Ltd | Wholesale & retail | 2026 |
| Best Hot Deals Limited | Wholesale & retail | 2020 |
| Best Online Bargains Ltd | Wholesale & retail | 2024 |
| Best@Care Limited | Health & social care | 2019 |
| Bethel Shape Limited | Real estate | 2015 |
| Betoken Ltd | Information & communication | 2016 |
| Beyond Business Group Ltd | Professional & scientific | 2022 |
| BFU Electronics Ltd | Wholesale & retail | 2026 |
| BGA London Limited | Professional & scientific | 2008 |
| Bhavya & Joana Ltd | Wholesale & retail | 2020 |
| Bhoomi Properties Ltd | Real estate | 2021 |
| BI Consultant Ltd | Information & communication | 2007 |
| BID Head Ltd | Professional & scientific | 2025 |
| Big Stack Solutions Ltd | Professional & scientific | 2025 |
| Bindra Investments Ltd | Real estate | 2026 |
| Bioventora Ltd | Health & social care | 2026 |
| Bird and Wedge Limited | Construction | 2013 |
| Birdlow Mane Limited | Manufacturing | 2025 |
| Bisbud Ltd | Construction | 2011 |
| Bishop & Associates Holdings Ltd. | Financial services | 2013 |
| Bishop & Associates Surveyors Ltd | Professional & scientific | 2023 |
| Black Cat RE Limited | Real estate | 2019 |
| Black Creek Construction Ltd | Construction | 2022 |
| Black Creek Property Development Ltd | Construction | 2024 |
| Black Nurses & Midwives UK Community Interest Company | Professional & scientific | 2024 |
| Blackrigde Ltd | Information & communication | 2026 |
| Blackties Technologies Ltd | Information & communication | 2022 |
| Blackvault Systems Ltd | Information & communication | 2025 |
| Blakes Management Limited | Hospitality | 2010 |
| Blanford Design & Build Limited | Construction | 2013 |