| Bryan Edge Associates Limited | Professional & scientific | 2024 |
| Bryant Travel Ltd | Transport & logistics | 2016 |
| Bryson (Construction) Limited | Construction | 2003 |
| BSE PVT Limited | Health & social care | 2024 |
| BSM Metal & Rubbish Recycling Ltd | Extraterritorial | 2015 |
| BSP Projects South Limited | Construction | 2017 |
| BTW Fusion Ltd | Manufacturing | 2015 |
| Bubbles and Sharky Property Limited | Real estate | 2024 |
| Bucchinc Ltd | Financial services | 2020 |
| Bucci Trading Ltd | Hospitality | 2022 |
| Buchanan Group Holdings Limited | Financial services | 2021 |
| Bucket List Holdings Limited | Water & waste | 2004 |
| Buckingham Old Portsmouth Apartments Ltd | Construction | 2026 |
| Buckland Investment Partners Ltd | Professional & scientific | 2022 |
| Buckman Media Ltd | Information & communication | 2021 |
| Budschips Ltd | Manufacturing | 2022 |
| Bugas Services Limited | Construction | 2020 |
| Build Recruitment Group Limited | Administrative & support | 2016 |
| Build Recruitment Limited | Administrative & support | 2010 |
| BUILD2BUILT Ltd | Construction | 2024 |
| Building & Engineering Services Limited | Construction | 1997 |
| Building and Property Investments Limited | Real estate | 2019 |
| Buildline Engineering Limited | Professional & scientific | 2025 |
| Buildsafe Solutions Limited | Professional & scientific | 2024 |
| Bulte Plastics (UK) Limited | Manufacturing | 1999 |
| Bumble BEE Cottage Limited | Information & communication | 2013 |
| Buoyz Toyz Boat Sales Limited | Wholesale & retail | 2025 |
| Burden Carpentry Services Limited | Construction | 2007 |
| Burnett & Burnett Ltd | Real estate | 2019 |
| Burns LHC Limited | Financial services | 2025 |
| Burpham House Management Company Limited | Professional & scientific | 2006 |
| Burr Associates Limited | Professional & scientific | 2010 |
| Burrage Marine Limited | Professional & scientific | 2018 |
| Burrcroft Property Services Limited | Construction | 2019 |
| Burrfields Car Sales Ltd | Wholesale & retail | 2011 |
| Bury Lodge Farm & Services Limited | Agriculture & fishing | 2025 |
| Business Bar Associates Limited | Professional & scientific | 2006 |
| Business Bar Club Limited | Extraterritorial | 2002 |
| Business Bar Commercial Services Limited | Administrative & support | 2010 |
| Business Bar Contractors Limited | Professional & scientific | 2010 |
| Business Bar Contracts Limited | Professional & scientific | 2010 |
| Business Bar Financial Limited | Real estate | 2010 |
| Business Bar Limited | Extraterritorial | 2002 |
| Business Bar Services Limited | Administrative & support | 2010 |
| Business Consultancy Limited | Professional & scientific | 2021 |
| Business Edge Properties Limited | Real estate | 2010 |
| Business Health Partnership Limited | Professional & scientific | 2015 |
| Business Safety First Ltd | Other services | 2018 |
| Busy BEE Preschool and Nursery Ltd | Education | 2026 |
| Buteo Ornithology and Ecology Ltd | Professional & scientific | 2024 |
| Butler & Butler Group Ltd | Financial services | 2018 |
| Butler & Butler Property Ltd | Real estate | 2018 |
| Butlers of Bosham Ltd | Hospitality | 2006 |
| Butser Education CIC | Hospitality | 2009 |
| Butser Farms Limited | Agriculture & fishing | 2007 |
| Butterfly Effect Consultants Ltd | Professional & scientific | 2019 |
| Butterfly Enterprise Limited | Transport & logistics | 2020 |
| Butterfly Group Enterprises Limited | Financial services | 2023 |
| Butterfly Properties TS Limited | Real estate | 2024 |
| Butterfly Properties TS1 Limited | Real estate | 2024 |
| Butterfly Tyres Limited | Wholesale & retail | 2024 |
| Butteriss Accountants Ltd | Professional & scientific | 2025 |
| Button UP Baby Limited | Wholesale & retail | 2015 |
| Buzions Environmental and Healthcare Services Ltd | Professional & scientific | 2025 |
| Buzzard Consultants Limited | Professional & scientific | 2019 |
| Buzzword Creative Southern Limited | Professional & scientific | 2004 |
| BW Technical Solutions Ltd | Manufacturing | 2021 |
| BX4 Properties Ltd | Construction | 2023 |
| BY Chloe Leah Beauty Limited | Other services | 2019 |
| BYE BYE SIM Limited | Wholesale & retail | 2025 |
| Byfarahk Limited | Professional & scientific | 2025 |
| Byrne Rail Services Ltd | Transport & logistics | 2016 |
| Bywest Design Limited | Professional & scientific | 2024 |
| C & G Building Contractors (UK) Ltd | Construction | 2005 |
| C & J Property Holdings Ltd | Construction | 2019 |
| C & L Urology Services Limited | Health & social care | 2022 |
| C & P Trading Ltd | Construction | 2016 |
| C and a Storage Ltd | Transport & logistics | 2023 |
| C and P Financial Services Limited | Financial services | 2022 |
| C Armstrong Carpentry Ltd | Construction | 2023 |
| C C Landscapes Ltd | Construction | 2022 |
| C G Carpentry Limited | Construction | 2019 |
| C G Plumbing & GAS Services Limited | Construction | 2012 |
| C GEE Services Limited | Manufacturing | 2013 |
| C Hibbert Brickwork Limited | Construction | 2022 |
| C Hill Electrical Ltd | Construction | 2019 |
| C J & R Gaskell Limited | Professional & scientific | 2019 |
| C J Audio Visual Services Limited | Other services | 2015 |
| C J Lewis Limited | Professional & scientific | 2021 |
| C J O'Donoghue Ltd | Construction | 2019 |
| C J Roofing & Renewables Ltd | Construction | 2025 |
| C K Maintenance Services Limited | Construction | 2020 |
| C L Property Holdings Hants Limited | Real estate | 2024 |
| C L Standen Holdings Limited | Financial services | 2004 |
| C N Premier Properties Ltd | Real estate | 2026 |
| C N Rail Limited | Construction | 2018 |
| C P Landscaping Ltd | Construction | 2023 |
| C Power Holdings Ltd | Financial services | 2025 |
| C R Electrics Ltd | Construction | 2023 |
| C T Home Solutions Limited | Real estate | 2021 |