| BS Films Services Limited | Administrative & support | 2017 |
| BSM Events Limited | Arts & recreation | 2015 |
| BT Contractors Ltd | Construction | 2023 |
| BT Retail Ventures Limited | Wholesale & retail | 2024 |
| BTL Enterprises Limited | Financial services | 2013 |
| BTL Industries Limited | Administrative & support | 2003 |
| Bubble Nugget Limited | Construction | 2022 |
| Buckingham Survey and Design Limited | Other services | 2020 |
| Buckland Drive (MK) Management Company Limited | Households | 2005 |
| Budeca Source Limited | Professional & scientific | 2025 |
| Build Right RP Limited | Construction | 2024 |
| Build UP Solutions Ltd | Construction | 2021 |
| Build Wright Limited | Construction | 2019 |
| Builders Emporium Limited | Wholesale & retail | 2010 |
| Building Engineering Solutions Limited | Construction | 2002 |
| Building Futures Property Ltd | Real estate | 2026 |
| Building Gorga Ltd | Construction | 2022 |
| Building Surplus UK Ltd | Information & communication | 2023 |
| Buildsway Ltd | Construction | 2019 |
| Built in the Shed Limited | Wholesale & retail | 2019 |
| Built Trust Consultancy Ltd | Professional & scientific | 2026 |
| Bulijoe Limited | Health & social care | 2018 |
| Bullet Pictures Ltd | Information & communication | 2012 |
| Bumbi Trans Limited | Transport & logistics | 2023 |
| Bumperz Body Repairs Ltd | Wholesale & retail | 2024 |
| Bunyan (Luton) Ltd | Real estate | 2022 |
| Bunyan Development Ltd | Real estate | 2024 |
| Bunyan Investments (Luton) Ltd | Real estate | 2022 |
| Bunyan Plastering Contractors Limited | Construction | 2004 |
| Bure Ltd | Wholesale & retail | 2019 |
| Burellis Limited | Hospitality | 2024 |
| Burger Box BB Ltd | Hospitality | 2025 |
| Burger Box STV Ltd | Hospitality | 2022 |
| Burgess Place Management Company Ltd | Real estate | 2019 |
| Burleigh Time-Share Limited | Extraterritorial | 1982 |
| Burns Road Stores Limited | Hospitality | 1982 |
| Burnt Farm Management Company Limited | Households | 2021 |
| Burr Bridal Limited | Wholesale & retail | 2013 |
| Burrmount Property Developments Limited | Construction | 2012 |
| Burt Services Limited | Other services | 2018 |
| Bury Brook Properties Limited | Real estate | 2017 |
| Business Connexion Limited | Information & communication | 1995 |
| Businessmagnet Limited | Professional & scientific | 2004 |
| Busyhands Collectibles Ltd | Manufacturing | 2025 |
| Butler Residential Limited | Real estate | 2020 |
| Buttersteep SPV Ltd | Real estate | 2021 |
| Buttevant Properties Limited | Real estate | 2025 |
| Button Ltd | Education | 2026 |
| Buzzard Roofing Reports Limited | Construction | 2026 |
| BW Plaices Ltd | Real estate | 2024 |
| BWA Advisory Limited | Professional & scientific | 2024 |
| BWC Commercial Services Limited | Professional & scientific | 2024 |
| BY Ells Limited | Other services | 2024 |
| BY MAR Limited | Administrative & support | 2017 |
| Bytes Intelligence Resources Limited | Information & communication | 2013 |
| BZ BEE (Holdings) Limited | Construction | 2015 |
| C & D Fork Trucks Limited | Other services | 2004 |
| C and P Roofing Ltd | Other services | 2010 |
| C J Hutchings Services Ltd | Construction | 2021 |
| C J Kitchen Installations Ltd | Construction | 2017 |
| C Jennings Building Ltd | Construction | 2023 |
| C R Repairs Ltd | Administrative & support | 2019 |
| C Space Consulting Limited | Professional & scientific | 2024 |
| C W G Group Ltd | Construction | 2008 |
| C W G Roofing Ltd | Construction | 2020 |
| C&C Stone Ltd | Construction | 2012 |
| C&N Recruitment Services Ltd | Other services | 2022 |
| C&O Bouncy Castle Ltd | Arts & recreation | 2021 |
| C&S Consult Ltd | Professional & scientific | 2025 |
| C&V Accounting Limited | Professional & scientific | 2023 |
| C-Metric Scaffolding Ltd | Construction | 2017 |
| C. Prada Limited | Health & social care | 2011 |
| C.C Onoh Company Ltd | Health & social care | 2018 |
| C.Hawks Rigging Limited | Construction | 2015 |
| C.J.Electrical Ltd | Construction | 2023 |
| C.L.A Scaffolding Solutions Ltd | Construction | 2020 |
| C.Plumbing Ltd | Construction | 2022 |
| C10 ROU Ltd | Professional & scientific | 2017 |
| C2 Buildworks Ltd | Construction | 2025 |
| C3 Contracts Ltd | Construction | 2015 |
| Cable Markers and Idents Ltd | Construction | 2015 |
| Cabriolet Coupe Limited | Wholesale & retail | 2010 |
| Cacity Healthcare Solutions Ltd | Health & social care | 2021 |
| CAD Services Direct Limited | Manufacturing | 2007 |
| Cadzow Communications Consulting Limited | Other services | 1995 |
| Caelus Design Ltd | Professional & scientific | 2014 |
| Caernarvon Close 1966 Limited | Extraterritorial | 2014 |
| Cafe Rockingham Ltd | Hospitality | 2018 |
| Caffeluxe Limited | Manufacturing | 2015 |
| CAJ Developments Limited | Real estate | 2026 |
| Caldwell and Cook Metalworks Ltd | Manufacturing | 2026 |
| Calidwell Homes Limited | Construction | 2023 |
| Callan Group Ltd | Construction | 2022 |
| Calshire Limited | Information & communication | 2002 |
| Caltec Limited | Arts & recreation | 2025 |
| Calton Maintenance Ltd | Construction | 2025 |
| Calverts Driving Services Ltd | Transport & logistics | 2021 |
| CAM Centre Management Limited | Households | 1988 |
| CAM Store Solutions Limited | Transport & logistics | 2025 |
| Cambridge Country Club Estate Limited | Real estate | 2015 |