| Biophoenix Limited | Professional & scientific | 2013 |
| Birmingham City Glass Ltd | Manufacturing | 2026 |
| Blackguard Investments LLP | | 2022 |
| Blair Aitken Limited | Information & communication | 2023 |
| Block 4 Alpine Court Kenilworth RTM Limited | Households | 2014 |
| Blue INK Consulting Limited | Administrative & support | 2009 |
| Blue Jellyfish Ltd | Hospitality | 2025 |
| Blue Leaf Fuels Limited | Professional & scientific | 2021 |
| Blue OWL Consulting Ltd | Professional & scientific | 2023 |
| Blue Sealand Co., Ltd | Professional & scientific | 2018 |
| Blueberry Landscapes Limited | Administrative & support | 2011 |
| Bluebox Tech Limited | Information & communication | 2025 |
| BMB Contractors Limited | Construction | 2009 |
| Boan Industries Co., Ltd | Administrative & support | 2021 |
| Boca Holdings Limited | Financial services | 2023 |
| Boden Property Company Ltd | Real estate | 2022 |
| Boden Property Group Limited | Real estate | 2020 |
| Boden Property Management Ltd | Real estate | 2020 |
| Bodenspaces Limited | Real estate | 2018 |
| Bodyguard Protect Ltd | Wholesale & retail | 2022 |
| Bollands Consulting Ltd | Professional & scientific | 2010 |
| Boshun Trading Limited | Administrative & support | 2021 |
| Boss Belgium Ltd | Administrative & support | 2006 |
| Boston Fieldgate Limited | Real estate | 2015 |
| Boxing International Co., Ltd | Administrative & support | 2020 |
| Boxx Design Studio Ltd | Professional & scientific | 2021 |
| Braid Limited | Administrative & support | 2023 |
| Brailer Ltd | Manufacturing | 2018 |
| Brain Pilot Ltd | Administrative & support | 2025 |
| Brandit Gifts Co., Limited | Administrative & support | 2024 |
| Breathe Blue Spaces Ltd | Professional & scientific | 2023 |
| Breathe Green Spaces Ltd | Administrative & support | 2018 |
| Breda Plant Tech Co., Ltd | Extraterritorial | 2023 |
| Breedline Services Limited | Extraterritorial | 2004 |
| Brentwood Property Limited | Real estate | 2021 |
| Brewquest Coffee Ltd | Manufacturing | 2025 |
| Bridal Fusion Ltd | Wholesale & retail | 2022 |
| Brigg House Ltd | Professional & scientific | 2019 |
| Bright YAK Limited | Information & communication | 2013 |
| Bright-Side Psychology Limited | Health & social care | 2022 |
| Brightstone Recruitment Ltd | Administrative & support | 2010 |
| Brightstone Securities Limited | Real estate | 2015 |
| Brilliant PUB Company Limited | Hospitality | 2019 |
| Bristow Accountancy Limited | Professional & scientific | 2022 |
| British Equestrian Federation | Arts & recreation | 1996 |
| British Equestrian Federation Fund Limited | Arts & recreation | 1999 |
| British Equestrian Vaulting Limited | Other services | 1996 |
| British Horse Society(The) | Education | 1947 |
| British Riding Clubs | Education | 1998 |
| Brkn Ltd | Information & communication | 2022 |
| BRN Ltd | Real estate | 2022 |
| Brniko. Co., Ltd | Manufacturing | 2021 |
| Brook Farm Barn Estates Ltd | Real estate | 2021 |
| Brookhurst Court Management Company Limited(The) | Households | 1960 |
| Brookline Campers Limited | Administrative & support | 2015 |
| Brookline Cars Limited | Transport & logistics | 1979 |
| Brooks Taylor Projects Ltd | Professional & scientific | 2023 |
| Bsph (2008) Limited | Construction | 2008 |
| Bubble Way Limited | Administrative & support | 2026 |
| Bubbles Commercial Limited | Real estate | 2022 |
| Bubbles Estates Limited | Real estate | 2011 |
| Bubbles Translation Services Limited | Professional & scientific | 2003 |
| Buckingham Swimming Pools Group Limited | Construction | 2019 |
| Buckinghams of Kenilworth Limited | Wholesale & retail | 1988 |
| Buckyboo Ltd | Information & communication | 2021 |
| Bulkington Lets Ltd | Real estate | 2022 |
| Bullmon Co., Ltd | Extraterritorial | 2021 |
| Bultavi Ltd | Wholesale & retail | 2007 |
| Bump to Three (& Beyond!) Community Interest Company | Health & social care | 2012 |
| BUN Stop Ltd | Hospitality | 2024 |
| Burndept Home Ltd | Professional & scientific | 2023 |
| Business of Projects Limited | Professional & scientific | 2025 |
| Business Resource Commerce Ltd | Administrative & support | 2017 |
| Button Automotive Consulting Limited | Professional & scientific | 2016 |
| C & H Products Limited | Wholesale & retail | 2008 |
| C J Holmes (Building Contractors) Limited | Construction | 1979 |
| C T Planning Limited | Extraterritorial | 2000 |
| C&D International Trading Ltd | Administrative & support | 2026 |
| C.L. Ellis Ltd | Professional & scientific | 2010 |
| Caali | Financial services | 2018 |
| Cabinetry Factory Ltd | Administrative & support | 2020 |
| Cadentiauk Limited | Professional & scientific | 2017 |
| Cadtek Systems Limited | Information & communication | 1988 |
| CAE People Limited | Administrative & support | 2006 |
| Cahill Carpentry Contractors Ltd | Manufacturing | 2023 |
| Caishen Design Limited | Information & communication | 2015 |
| Cake Kingdom Limited | Professional & scientific | 2012 |
| CAL Property Limited | Real estate | 2015 |
| Calamari Royale Ltd | Arts & recreation | 2006 |
| Calgarth Limited Partnership | | 2008 |
| Call Runnings Ltd | Professional & scientific | 2025 |
| Cambridge Artificial Intelligence and Teaching Research Centre Limited | Extraterritorial | 2014 |
| Camel Clamp Ltd | Manufacturing | 2024 |
| Campers & Vans UK Holdings Ltd | Financial services | 2021 |
| Campers & Vans UK Ltd | Wholesale & retail | 2015 |
| Camps Management Ltd | Extraterritorial | 2015 |
| Canaan Trading Corporation Limited | Administrative & support | 2014 |
| Canei Solutions Limited | Information & communication | 2011 |
| Cangzhou Shengming United Internatioanl Co. Ltd | Administrative & support | 2024 |
| Cangzhou WSL International Trading Co., Ltd | Administrative & support | 2023 |