| Brikki Ltd | Construction | 2026 |
| Briknexus Ltd | Real estate | 2025 |
| Briksy Lettings Ltd | Real estate | 2026 |
| Brilliant Perception Limited | Information & communication | 2022 |
| Brindsar Limited | Real estate | 2021 |
| Bring Leads Ltd | Professional & scientific | 2025 |
| Bringing YOU Together Limited | Information & communication | 2013 |
| Brink Property Solutions Ltd | Real estate | 2017 |
| Brisq Group Limited | Financial services | 2025 |
| Bristle Buddy Ltd | Wholesale & retail | 2025 |
| Bristol Storage Vault Limited | Transport & logistics | 2026 |
| Bristol Van Repairs Ltd | Wholesale & retail | 2024 |
| Bristow Direct Limited | Wholesale & retail | 2023 |
| Brit CAP Ltd | Professional & scientific | 2023 |
| Britannia Archaeology Ltd | Professional & scientific | 2011 |
| Britannia Bulls Ltd | Hospitality | 2011 |
| Britannia Digital Innovations Ltd | Wholesale & retail | 2026 |
| Britannia Global Distribution Ltd | Wholesale & retail | 2025 |
| Britannia Guide Limited | Financial services | 2023 |
| Britannia School of Consulting Ltd | Education | 2018 |
| Britannia Taxi and Private Hire Service Limited | Transport & logistics | 2018 |
| Britannic Innovations Limited | Professional & scientific | 2025 |
| Britannica Auctions Ltd | Wholesale & retail | 2020 |
| Britbuydirect Limited | Wholesale & retail | 2023 |
| Britcom Ltd | Wholesale & retail | 2024 |
| British Veterinary Zoological Society | Professional & scientific | 2022 |
| Britisle Ltd | Wholesale & retail | 2024 |
| Britnova Ventures Ltd | Administrative & support | 2025 |
| Britravelstudy Ltd | Education | 2018 |
| Britscape Groundworks Ltd | Administrative & support | 2026 |
| Britz Fashion Outlet Ltd | Wholesale & retail | 2021 |
| Brizzle Property Maintenance Ltd | Construction | 2026 |
| BRM Rigging Ltd | Information & communication | 2021 |
| Broad Lane Consultants Ltd | Professional & scientific | 2026 |
| Broadmead (Liverpool) Management Company Limited | Real estate | 1974 |
| Broadmix Investments Limited | Other services | 2022 |
| Broads Property Management Ltd | Households | 2023 |
| Brockley Properties Management Limited | Real estate | 2025 |
| Bromley Windows and Doors Ltd | Construction | 2022 |
| Bromptons Farm Ltd | Hospitality | 2025 |
| Brook Close Management Limited | Households | 1994 |
| Brook Design and Property Services Limited | Construction | 2000 |
| Brook Reed Property Group Ltd | Real estate | 2023 |
| Brooke Odun Ltd | Arts & recreation | 2025 |
| Brookland Properties Ltd | Real estate | 2019 |
| Brooks Digital Marketing Limited | Professional & scientific | 2015 |
| Brooks Meadow Properties Ltd | Real estate | 2022 |
| Brookstone Ventures Ltd | Financial services | 2024 |
| Brotherscode Initiative Limited | Other services | 2025 |
| Broughton Advisory Ltd | Professional & scientific | 2024 |
| Brown Hound Group Limited | Professional & scientific | 2024 |
| Brown Women in Film CIC | Information & communication | 2026 |
| Browne & Found Ltd | Wholesale & retail | 2026 |
| Brownridge Property Investments Ltd | Real estate | 2022 |
| Browns Family Enterprise Limited | Health & social care | 2020 |
| Bruce Nixon Pfeiffer Consultancy Limited | Professional & scientific | 2019 |
| Bruehaus Projekt Ltd | Manufacturing | 2023 |
| Brunswick Place Limited | Real estate | 1996 |
| Bruynseels Ltd | Wholesale & retail | 2020 |
| BRV Property Ltd | Real estate | 2021 |
| BRV Services Limited | Information & communication | 2012 |
| Bryan J. Nunn Haulage Limited | Transport & logistics | 1991 |
| Bryn Valley Supplies Limited | Wholesale & retail | 2023 |
| BSC Ground Works Limited | Construction | 2025 |
| BSE Boilers Ltd | Construction | 2024 |
| BSE Hotel Group Limited | Financial services | 2025 |
| BSE Imports Limited | Wholesale & retail | 2025 |
| BSE Retail Limited | Wholesale & retail | 2016 |
| BSE Travel Ltd | Transport & logistics | 2018 |
| BSG Installations Ltd | Construction | 2022 |
| Bshp Limited | Professional & scientific | 2024 |
| BSN Consultancy Services Limited | Information & communication | 2024 |
| Bsns Health Ltd | Wholesale & retail | 2025 |
| Bsns Locums Ltd | Education | 2022 |
| Bsns Online Ltd | Wholesale & retail | 2023 |
| Bsns Properties Ltd | Real estate | 2025 |
| BST Spartathlon Team CIC | Arts & recreation | 2023 |
| BTA MC Ltd | Wholesale & retail | 2022 |
| BTC Property Services Limited | Construction | 2022 |
| BTE Hair Ltd | Wholesale & retail | 2026 |
| BTS Business Service Limited | Professional & scientific | 2004 |
| Btsl EOT Limited | Extraterritorial | 2023 |
| Bubbl WIN Ltd | Arts & recreation | 2026 |
| Bubbuk Ltd | Extraterritorial | 2021 |
| Bubby Upton LLP | | 2022 |
| Bubu & ROY Ltd | Wholesale & retail | 2025 |
| Bubutiny Ltd | Wholesale & retail | 2026 |
| Buckinghamshire Wellness Clinic Ltd | Other services | 2026 |
| Bucklan LLP | | 2018 |
| Buckstone Consulting Limited | Professional & scientific | 2025 |
| Budara Partners Ltd | Other services | 2025 |
| Budget Property Management Ltd | Households | 2022 |
| Buditu Consulting Ltd | Education | 2024 |
| Buen Eats Ltd | Hospitality | 2025 |
| Bufflers Limited | Hospitality | 2020 |
| BUG Pets Ltd | Wholesale & retail | 2023 |
| Build a Glow Ltd | Wholesale & retail | 2025 |
| Build Construct Group Ltd | Construction | 2022 |
| Build Elitefix Ltd | Construction | 2025 |
| Build Excellence Ltd | Wholesale & retail | 2025 |