| BO Ventures Ltd | Professional & scientific | 2022 |
| BOA 2 UK Ltd | Health & social care | 2023 |
| Boarding School Concern | Education | 2019 |
| Boat Renovations Ltd | Manufacturing | 2023 |
| Boathouse Court Properties Ltd | Real estate | 2015 |
| Boatspeed Ltd | Manufacturing | 2018 |
| BOB Black Construction Limited | Construction | 1986 |
| BOB Black Joinery Limited | Construction | 2011 |
| BOB Black Limited | Construction | 2015 |
| Bobek Aircraft Solutions Ltd | Manufacturing | 2024 |
| BOBO1984 Ltd | Manufacturing | 2025 |
| Bodies in the Bookshop Ltd | Wholesale & retail | 2024 |
| Bodmin Leather Co Limited | Manufacturing | 1993 |
| Bodosnow Ltd | Manufacturing | 2024 |
| Body Shape Fitness ELY Ltd | Arts & recreation | 2024 |
| Bodywork Company Cambridge Limited | Education | 2014 |
| BOE Property Group Ltd | Real estate | 2023 |
| Boedal Limited | Manufacturing | 2008 |
| Bofa Import and Export Co., Ltd | Wholesale & retail | 2018 |
| Bogdan BODO93 Ltd | Manufacturing | 2026 |
| Bogdan Engineering Ltd | Manufacturing | 2026 |
| Bohemian Smartlytics Limited | Information & communication | 2020 |
| Bohemian Writers Club Limited | Information & communication | 2024 |
| Bohuitong Ltd | Administrative & support | 2026 |
| BOILERS2BATHROOMS Plumbing & Heating Ltd | Extraterritorial | 2007 |
| Boing Kids Limited | Other services | 2014 |
| Bokkie Properties Limited | Real estate | 2020 |
| Bokkie Properties OS Limited | Real estate | 2022 |
| Boktarpur Express Ltd | Hospitality | 2025 |
| Boland & Reeve Limited | Administrative & support | 2011 |
| Boldi Marian Ltd | Manufacturing | 2024 |
| Bolo Trans Ltd | Transport & logistics | 2018 |
| Boltech Integrated Ltd | Wholesale & retail | 2024 |
| Bolton's PIT Company Limited | Arts & recreation | 2010 |
| Bolu Trading Company Ltd | Mining & quarrying | 2018 |
| Bombgo Pixel E-Commerce Co., Limited | Wholesale & retail | 2025 |
| Bonci Aviation Consulting Ltd | Manufacturing | 2025 |
| Bond Architecture Ltd | Professional & scientific | 2022 |
| Bond Haiducu Ltd | Manufacturing | 2023 |
| Bondal Shore Ltd | Financial services | 2010 |
| Bondchem International Limited | Extraterritorial | 2023 |
| Bondi Art Limited | Manufacturing | 2026 |
| Bondina Investments | Financial services | 2021 |
| Boneng Transmission Co., Ltd | Extraterritorial | 2014 |
| Bongolo Bill Ltd | Manufacturing | 2026 |
| Bonne Bouchée Limited | Hospitality | 2021 |
| Bonroy Living Industrial Limited | Manufacturing | 2026 |
| Boondoggle Limited | Information & communication | 2015 |
| Boost Recycling Limited | Water & waste | 2007 |
| Boostara Investment Group Ltd. | Information & communication | 2025 |
| Booterra Ltd | Information & communication | 2022 |
| Bootins Limited | Information & communication | 2026 |
| Boqnov Composites Ltd | Manufacturing | 2025 |
| Borakis Ltd | Administrative & support | 2010 |
| Boreham Electrical Ltd | Construction | 2018 |
| Boris Carbon Racing Team Ltd | Manufacturing | 2025 |
| Borley Brothers Engineering Limited | Construction | 2020 |
| Born 2 Lead CIC | Wholesale & retail | 2025 |
| Born for FLY Ltd | Manufacturing | 2025 |
| Borough Architects Limited | Professional & scientific | 2018 |
| Borough Productions Limited | Information & communication | 2007 |
| Boroviak Consulting Ltd | Professional & scientific | 2025 |
| BOS Brothers Limited | Wholesale & retail | 2024 |
| Boscht Limited | Manufacturing | 2025 |
| Bost Instruments Group Limited | Manufacturing | 2025 |
| Boston Gate Management Company Limited | Households | 2018 |
| Boswell & SON Limited | Manufacturing | 1996 |
| Boswell's Sawston Limited | Wholesale & retail | 2020 |
| Bosworth Independent School Limited | Education | 1997 |
| Botany Foodie Limited | Wholesale & retail | 2022 |
| Botly Limited | Manufacturing | 2015 |
| Botonea Andrei Air Space Ltd | Manufacturing | 2026 |
| Bottisham Barbers Ltd | Other services | 2016 |
| Bottisham Farming Limited | Agriculture & fishing | 2011 |
| Bottisham School of Motoring Ltd | Education | 2011 |
| Bottisham Vehicle Services Limited | Wholesale & retail | 2014 |
| Bottleproof Cocktails Ltd | Manufacturing | 2017 |
| Bottles & Cans Limited | Wholesale & retail | 2016 |
| Bougeoir Ltd | Manufacturing | 2025 |
| Boughton Hall Management Ltd | Real estate | 2008 |
| Bould Brother Venture 3 Limited | Hospitality | 2025 |
| Bould Brothers Ventures Limited | Hospitality | 2021 |
| Bould Investments Limited | Construction | 2021 |
| Bounce the Ball Ltd. | Education | 2011 |
| Boundary Court Residents Company Limited | Households | 1985 |
| Boundless International Business(Uk) Ltd | Wholesale & retail | 2023 |
| Bounds Campsite Ltd | Hospitality | 2020 |
| Bounty Hill Limited | Professional & scientific | 2025 |
| Bourn Airfield Limited | Professional & scientific | 1995 |
| Bourn Bioscience Limited | Health & social care | 2005 |
| Bourn Church of England Primary Academy | Education | 2011 |
| Bourn Hall Holdings Limited | Professional & scientific | 2020 |
| Bourn Hall Investments Limited | Professional & scientific | 2020 |
| Bourn Hall Limited | Health & social care | 1985 |
| Bourn Timber Partnership | | 1994 |
| Bourn Vale Management Ltd | Households | 2023 |
| Bourne Bridge Contract Hire Limited | Administrative & support | 2016 |
| Bournemouth Collegiate School Limited | Education | 2018 |
| Bourner Boards Limited | Real estate | 1987 |
| Boutros Bear Ltd | Other services | 2018 |