| Bumble Bells Ltd | Health & social care | 2023 |
| Bump and Baby Photography Ltd | Professional & scientific | 2024 |
| Buna Limited | Information & communication | 2017 |
| Bundledjoysco Ltd | Wholesale & retail | 2024 |
| Bunga Consultancy Services Limited | Professional & scientific | 2012 |
| Bunu Medics Limited | Professional & scientific | 2015 |
| Bunyoro Kitara Convention and Events Ltd | Health & social care | 2024 |
| Burdoski Ltd | Professional & scientific | 2023 |
| Bureaucom Limited | Health & social care | 1982 |
| Burley House Group Ltd | Financial services | 2024 |
| Burley House Property Ltd | Real estate | 2024 |
| Burns Architecture Limited | Professional & scientific | 2021 |
| Burtons Law Limited | Administrative & support | 2023 |
| Bush Property Limited | Real estate | 2009 |
| Business Catering Solutions Northants Ltd | Hospitality | 2018 |
| Business Excellence Security Ltd | Administrative & support | 2025 |
| Business Excellence Solutions Limited | Professional & scientific | 2023 |
| Business Language Center Limited | Education | 2010 |
| Business Resource Centre Limited | Professional & scientific | 2010 |
| Business Services UK Group Limited | Professional & scientific | 2026 |
| BUT ARE YOU Listening? Limited | Health & social care | 2025 |
| BUT Couriers Ltd | Transport & logistics | 2020 |
| Butterfly Jerk Ltd | Hospitality | 2025 |
| Butts Green AVE Ltd | Construction | 2005 |
| Butts Green RD Ltd | Construction | 1993 |
| Buy a BUS Ltd | Wholesale & retail | 2023 |
| Buzaid Ltd | Hospitality | 2021 |
| Buzzard Brands Ltd | Wholesale & retail | 2024 |
| Bvalony UK Limited | Energy | 2022 |
| BW Movement Ltd | Transport & logistics | 2026 |
| BWF Construction Group Limited | Construction | 2023 |
| BWS Sports Group Ltd | Professional & scientific | 2026 |
| BWT Construction Holding Group Ltd | Construction | 2022 |
| BY Transports Ltd | Transport & logistics | 2024 |
| Byke Ltd | Wholesale & retail | 2022 |
| Byrne Builders Ltd | Manufacturing | 2019 |
| Byteframe Digital Ltd | Information & communication | 2018 |
| Bytewais Consulting Limited | Information & communication | 2025 |
| C & D Roofing Services Ltd | Construction | 2018 |
| C a Interiors Limited | Construction | 2004 |
| C Copley Brickwork Limited | Construction | 2024 |
| C Humm Utilities Limited | Energy | 2019 |
| C R Butler Cars and Commercials Limited | Wholesale & retail | 2002 |
| C R Butler Trading Limited | Extraterritorial | 2003 |
| C Root Design & Build Limited | Construction | 2009 |
| C S Bailey Consulting Ltd | Health & social care | 2012 |
| C Tanase Ltd | Construction | 2023 |
| C&F Maintenance Solutions Ltd | Construction | 2024 |
| C&P 123 Limited | Extraterritorial | 2010 |
| C-Air Anaesthesia Ltd | Health & social care | 2020 |
| C. Berwick & Sons Limited | Wholesale & retail | 2008 |
| C. Hawkes Ltd | Construction | 2015 |
| C. Ward Real Estate Ltd | Real estate | 2025 |
| C.A.P. Developments Limited | Construction | 1989 |
| C.M. Education Limited | Education | 2018 |
| C4S Software Limited | Information & communication | 2011 |
| CA Specialist Services Ltd | Other services | 2020 |
| Caaron Ltd | Real estate | 2019 |
| Cable Europe Limited | Information & communication | 2001 |
| Cabn Ltd | Wholesale & retail | 2024 |
| Cade Home Solutions Limited | Construction | 2021 |
| Cadman Financial Advisory Limited | Professional & scientific | 2021 |
| Cafe Koinonia Limited | Hospitality | 2026 |
| Cafe MAZ Ltd | Hospitality | 2017 |
| Caffiend Coffee Craft Ltd | Wholesale & retail | 2023 |
| Cahani Plumbing Limited | Construction | 2016 |
| Calamuchita Ltd | Extraterritorial | 2021 |
| Calford Seaden (Health & Safety) Limited | Professional & scientific | 1995 |
| Calfords Group LLP | | 2022 |
| Calfords LLP | | 2022 |
| Calfordseaden LLP | | 2005 |
| Calibre Education Consulting Ltd | Education | 2020 |
| Callow Broadcast Services Limited | Information & communication | 2013 |
| Camaxiloo Limited | Health & social care | 2023 |
| Camfort Property Ltd | Real estate | 2026 |
| Campaign Cart Ltd | Wholesale & retail | 2019 |
| CAN DO for YOU Limited | Administrative & support | 2021 |
| CAN Kani OZ Ltd | Other services | 2023 |
| Canbarber Ltd | Other services | 2025 |
| Candour Auto Tech UK Ltd | Professional & scientific | 2023 |
| Candyman Productions Ltd | Information & communication | 2015 |
| Canine Valley Ltd | Wholesale & retail | 2023 |
| Canon Garth Limited | Wholesale & retail | 1993 |
| Canterbury City Scaffolding Ltd | Construction | 2015 |
| Canterbury Homes Ltd | Construction | 2012 |
| CAP Construction Limited | Professional & scientific | 2003 |
| CAP Consultancy Services Limited | Professional & scientific | 2016 |
| Capital Pleasure Boats Limited | Transport & logistics | 2012 |
| Capital Property Investment and Development Ltd | Real estate | 2023 |
| Capital Technology Group Ltd | Wholesale & retail | 2026 |
| Capitawise Ltd | Information & communication | 2022 |
| Capitol Equipment Limited | Wholesale & retail | 2009 |
| Cappa Holdings Limited | Households | 2024 |
| Cappron Limited | Financial services | 2012 |
| Capstone Properties & Interiors Limited | Real estate | 2024 |
| Captain Consulting (UK) Limited | Health & social care | 2010 |
| CAPTIV8 Limited | Information & communication | 2021 |
| Cardinal Restoration Limited | Other services | 2003 |
| Cardio Surgical Solutions Ltd | Health & social care | 2013 |
| Care and Help Ltd | Administrative & support | 2013 |