| Bright 2501 Limited | Wholesale & retail | 2025 |
| Bright 2502 Limited | Wholesale & retail | 2025 |
| Brightbags Education and First AID Services Ltd | Administrative & support | 2024 |
| Brightstone Education Partners Ltd | Administrative & support | 2026 |
| Brightwalton Bloodstock Limited | Agriculture & fishing | 2022 |
| Brightwalton Stud Limited | Agriculture & fishing | 2013 |
| Brimstone Living 2 Ltd | Real estate | 2016 |
| Brimstone Living 3 Limited | Construction | 2017 |
| Brimstone Living 4 Limited | Construction | 2020 |
| Brimstone Living 5 Ltd | Construction | 2022 |
| Brimstone Living 6 Ltd | Construction | 2024 |
| Brimstone Living 8 Ltd | Construction | 2025 |
| Brimstone Living 9 Limited | Real estate | 2025 |
| Brimstone Living Ltd | Construction | 2013 |
| Brinxley Pools & Flooring Limited | Construction | 2014 |
| Briq Technology Limited | Professional & scientific | 2016 |
| Bristol Veterinary Behaviour Specialists Limited | Professional & scientific | 2026 |
| British Industrial Truck Association Limited | Manufacturing | 1985 |
| Brittex Engineering Limited | Manufacturing | 1998 |
| Briym Ltd | Health & social care | 2022 |
| Broadhill Consultancy Limited | Professional & scientific | 2020 |
| Broadseed Ltd | Wholesale & retail | 2025 |
| Brockwood Carpentry & Construction Ltd | Construction | 2020 |
| Brookers Event Trucking Ltd | Transport & logistics | 2016 |
| Brookhill Woods Limited | Real estate | 2021 |
| Brookhouse Racing Ltd | Arts & recreation | 2022 |
| Brooklyn 99 Limited | Information & communication | 2015 |
| Brotherton Newco Limited | Financial services | 2025 |
| Broughton Mceleavey Limited | Wholesale & retail | 2025 |
| Browbands UK Ltd | Wholesale & retail | 2025 |
| Brucciani Studios Ltd | Professional & scientific | 2026 |
| Brynmellin Land Investments Limited | Construction | 2003 |
| BTM Group Ltd | Other services | 2025 |
| Bucklebury Shire Limited | Real estate | 2025 |
| Budding Film Production Ltd | Information & communication | 2019 |
| Budget Bikes Limited | Wholesale & retail | 2004 |
| Build Maintain Refurb Ltd | Construction | 2018 |
| Buildeck Limited | Manufacturing | 2020 |
| Buildeck Scaffold Systems Limited | Extraterritorial | 2020 |
| Building Big Things Ltd | Financial services | 2018 |
| Buildit Construction & Landscaping Ltd | Construction | 2026 |
| Bulb Interiors Limited | Construction | 2005 |
| Bulldog Service Station Limited | Wholesale & retail | 1959 |
| Bullfinch Homes Limited | Construction | 1998 |
| Bumbi B Ltd | Professional & scientific | 2020 |
| Burbage Cricket Centre of Excellence Limited | Arts & recreation | 2023 |
| Burcas Limited | Manufacturing | 1947 |
| Burfield Management Company Limited | Households | 1995 |
| Burghclere Sports Club Ltd | Hospitality | 2016 |
| Burnard Advisory Limited | Professional & scientific | 2026 |
| Burrell Road 1966 Limited | Extraterritorial | 2015 |
| Burton Brickwork Ltd | Construction | 2017 |
| Business Energy Mis-Selling Limited | Administrative & support | 2023 |
| Business Energy Reclaim and Refunds Limited | Administrative & support | 2023 |
| Business Risk and Resilience Ltd | Administrative & support | 2019 |
| Butterfield House Company Ltd | Households | 2024 |
| Butterlump Stone Limited | Real estate | 2022 |
| Buttermere Land Reclamation Company Limited | Real estate | 1980 |
| Buyerology Ltd | Information & communication | 2021 |
| BW Print and Design Limited | Manufacturing | 2018 |
| BWB Technologies Ltd | Manufacturing | 2005 |
| BWH Group Ltd | Administrative & support | 2017 |
| BWM Holdings UK Ltd | Financial services | 2015 |
| BY DR MEG Limited | Other services | 2015 |
| BYE Holdings Limited | Financial services | 2012 |
| Byrehill Project Services Ltd | Construction | 2016 |
| C & E Groundworks Ltd | Construction | 2013 |
| C & N Renovations Limited | Construction | 2022 |
| C - Constantin Kitchen Specialist Limited | Construction | 2016 |
| C a Belcher & Sons Transport Limited | Transport & logistics | 2024 |
| C and L Building Services Ltd | Construction | 2013 |
| C Hammond Consulting Limited | Professional & scientific | 2015 |
| C M R Executive Limited | Professional & scientific | 1993 |
| C&I UK Holdings Limited | Manufacturing | 2026 |
| C&Jg Properties Limited | Real estate | 2019 |
| C&R Engineering Limited | Financial services | 2010 |
| C. Castelli Decorators Limited | Construction | 2003 |
| C.B.S. (2002) Ltd | Construction | 2002 |
| C.W. Bone Developments Limited | Wholesale & retail | 1983 |
| C3PL Limited | Administrative & support | 2017 |
| Cabco Limited | Other services | 1988 |
| Cable & Wireless Aspac Holdings Limited | Professional & scientific | 2003 |
| Cable & Wireless CIS Services Limited | Information & communication | 1994 |
| Cable & Wireless Communications Data Network Services Limited | Information & communication | 1986 |
| Cable & Wireless Europe Holdings Limited | Professional & scientific | 2003 |
| Cable & Wireless Global Telecommunication Services Limited | Administrative & support | 2000 |
| Cable & Wireless UK Holdings Limited | Professional & scientific | 1999 |
| Cable & Wireless Worldwide Limited | Information & communication | 2009 |
| Cable and Wireless (India) Limited | Information & communication | 1994 |
| Cable and Wireless Nominee Limited | Information & communication | 1996 |
| Cable Systems Limited | Wholesale & retail | 1982 |
| Cadmatic Engineering Services Limited | Manufacturing | 2003 |
| Caerus:Uk Limited | Other services | 2017 |
| Caestus Limited | Information & communication | 2001 |
| CAF Commercials Ltd | Wholesale & retail | 2024 |
| Cafe Larry Limited | Real estate | 2021 |
| Calcemy Ltd | Information & communication | 2025 |
| Caldey Corporate Finance Limited | Financial services | 2020 |
| Calibar Ltd | Construction | 2015 |
| Calibre Research Ltd | Professional & scientific | 2009 |