| Boltzin Ltd | Information & communication | 2026 |
| Bolu Oyewale Ltd | Administrative & support | 2017 |
| Bombero Padel UK Limited | Manufacturing | 2025 |
| Bonell Property Limited | Real estate | 2014 |
| Bonell Property Renovation Limited | Construction | 2015 |
| Bonie Limited | Wholesale & retail | 2023 |
| Bonneville Gardens (Freehold) Limited | Real estate | 2001 |
| Bookfeast Ltd | Wholesale & retail | 2026 |
| Bookhaus Capital Limited | Wholesale & retail | 2025 |
| Bookkeepers Cgro Limited | Professional & scientific | 2022 |
| Bordon Phase 4 (Vistry Group) Estate Management Limited | Households | 2025 |
| Borough Mews Management Co Limited | Households | 2001 |
| BOS Electrical Services Limited | Energy | 2007 |
| Boss Energy Group Ltd | Construction | 2026 |
| Bostan Transport Ltd | Transport & logistics | 2025 |
| Boston Scientific Limited | Wholesale & retail | 1992 |
| Boston West Holiday Park Ltd | Hospitality | 2020 |
| Botwellears Limited | Wholesale & retail | 2024 |
| Botwellears Properties Ltd | Construction | 2005 |
| Bounce Back Finance Limited | Professional & scientific | 2020 |
| Boundary Way (Saltney) Management Company Limited | Households | 2007 |
| Boundarypoint Limited | Administrative & support | 2004 |
| Boundless EC UK Ltd | Wholesale & retail | 2022 |
| Bourne Meadow Management Ltd | Households | 2021 |
| Bovi Commerce Limited | Wholesale & retail | 2025 |
| Bovinet Ltd | Information & communication | 2026 |
| Bovingdon Dance Academy Ltd | Education | 2026 |
| Bovingdon Drycleaners Ltd | Other services | 2021 |
| Bovingdon Flooring Ltd | Manufacturing | 2020 |
| Bovingdon Pre-School | Education | 2004 |
| Bovingdon Spice House Ltd | Hospitality | 2017 |
| Bowden Chase Residents Management Company Limited | Households | 2018 |
| Bowlplex European Leisure Limited | Extraterritorial | 2005 |
| Bowlplex Limited | Extraterritorial | 1976 |
| Bowlplex Properties Limited | Extraterritorial | 2005 |
| Boxer Pubs and Co Ltd | Hospitality | 2024 |
| Boxmoor AV Ltd | Construction | 2024 |
| Boxmoor Brazilian Jiu-Jitsu Ltd | Arts & recreation | 2018 |
| Boxmoor Brickwork Limited | Construction | 2023 |
| Boxmoor Coffee & Wine Ltd | Wholesale & retail | 2019 |
| Boxmoor Construction Limited | Construction | 2009 |
| Boxmoor Consulting Group Limited | Information & communication | 2026 |
| Boxmoor Contracting Limited | Construction | 2017 |
| Boxmoor Decorating Limited | Construction | 2020 |
| Boxmoor Properties LLP | | 2018 |
| Boxmoor Solutions Limited | Professional & scientific | 2014 |
| Boxmoors Chippy Limited | Hospitality | 2024 |
| Boxmor Ltd | Professional & scientific | 2023 |
| Boxted Business Park Ltd | Real estate | 2020 |
| Boyle Clothing Ltd | Wholesale & retail | 2023 |
| Bozi Design Ltd | Professional & scientific | 2021 |
| Bphh Limited | Real estate | 2015 |
| BQ Productions Ltd | Information & communication | 2020 |
| Bradbury & Saville Properties Ltd | Real estate | 2021 |
| Bradley David Developments Limited | Real estate | 2016 |
| Bradson Services Ltd | Construction | 2008 |
| Braemer Management Company Limited | Households | 1974 |
| Brainstorm Advertising Ltd | Professional & scientific | 2008 |
| Brak Services Ltd | Wholesale & retail | 2021 |
| Brambledown (Maidstone) Management Company Limited | Households | 2016 |
| Bramchell Ltd | Real estate | 2021 |
| Bramcote Grange Resident Management Company Limited | Households | 2024 |
| Brand Buff Ltd | Professional & scientific | 2021 |
| Brand Everything Ltd | Manufacturing | 2020 |
| Branksome Homes Limited | Construction | 2014 |
| Bransom Retail Systems Limited | Information & communication | 1990 |
| Brass Beast Limited | Professional & scientific | 2024 |
| Brave Ascent CIC | Professional & scientific | 2021 |
| Brave Consulting Limited | Professional & scientific | 2023 |
| Bravo Blinds and Shutters Ltd | Other services | 2018 |
| Bravospirk Electrical Ltd | Construction | 2026 |
| Brayans Ltd | Wholesale & retail | 2026 |
| Brayton Park Limited | Arts & recreation | 2024 |
| Brazen Productions Ltd | Information & communication | 2017 |
| Brceu Ltd | Information & communication | 2026 |
| BREAD4SOUL Ltd | Other services | 2023 |
| Breathe (Aldham House Lane) Management Company Limited | Households | 2007 |
| Breen Transport Limited | Transport & logistics | 2025 |
| Bren 2 Designs Limited | Professional & scientific | 2007 |
| Brent Diamond Property Limited | Real estate | 2018 |
| Brent Street Management Company Limited | Households | 1996 |
| Brewer's Cleans Ltd | Administrative & support | 2024 |
| Brewfest Ltd | Hospitality | 2023 |
| Breyting Ltd | Other services | 2017 |
| Bricklayers Bar Restaurant Ltd | Hospitality | 2003 |
| Brickley Group Ltd | Information & communication | 2022 |
| Bricks Silverstone Holdco 1 Limited | Financial services | 2021 |
| Bricks Silverstone Holdco 2 Limited | Financial services | 2021 |
| Bricks Silverstone Holdco 3 Limited | Financial services | 2023 |
| Bricks Silverstone Holdco 4 Limited | Financial services | 2023 |
| Brickstone Construction Limited | Construction | 2015 |
| Bridge Consulting Group Limited | Financial services | 2015 |
| Bridge Facilities Engineers Limited | Administrative & support | 1999 |
| Bridle Wood (Residents Management Company) Limited | Households | 2016 |
| Bright and Tidy Solutions Ltd | Administrative & support | 2025 |
| Bright Comet Ltd | Information & communication | 2013 |
| Bright Finish Ltd | Construction | 2022 |
| Bright Mind Tutors Ltd | Education | 2023 |
| Bright Property Holdings Limited | Administrative & support | 2005 |
| Brightfield Care Ltd | Administrative & support | 2018 |