| Bluesky Property Management Limited | Real estate | 1982 |
| Bluprint Solutions Ltd | Financial services | 2016 |
| BM Vehicle Services Ltd | Financial services | 2024 |
| Bodhibox Amateur Boxing CIC | Arts & recreation | 2026 |
| Bodhibox Ltd | Arts & recreation | 2024 |
| Body by Bridie Ltd | Education | 2025 |
| Bole SO Nihaal Investment (UK) Ltd | Real estate | 2021 |
| Bookaero Limited | Administrative & support | 2000 |
| Borderless Waves Ltd | Information & communication | 2023 |
| Bosun Studio Ltd | Professional & scientific | 2021 |
| Bosun's Locker Ltd | Real estate | 2026 |
| Bound & Boundless Ltd | Manufacturing | 2021 |
| Boundless Promo UK Limited | Professional & scientific | 2017 |
| Bowmer Consulting Limited | Professional & scientific | 2022 |
| Brand Lateral Ltd | Professional & scientific | 2012 |
| Brands LEX Limited | Professional & scientific | 2026 |
| Bratchen Technology Limited | Administrative & support | 2014 |
| Brenley Park LLP | | 2010 |
| Brewers Yard Management Co. Ltd | Real estate | 2016 |
| Brick Tech Building Solutions Limited | Construction | 2013 |
| Brick Tech Holdings Limited | Real estate | 2019 |
| Bridge Street Hitchin Limited | Real estate | 2025 |
| Bridget's Broadcasting Company Ltd | Information & communication | 2014 |
| Bridgway Global Ltd | Professional & scientific | 2023 |
| Bright and Smart IT Solutions Ltd | Information & communication | 2025 |
| Brighton Rock Limited | Information & communication | 2014 |
| Britannia Domestic Services Ltd | Administrative & support | 2019 |
| British Indian Rugby Development CIC | Education | 2026 |
| British Society of Criminology | Other services | 1998 |
| Broadwater Hundred Limited | Extraterritorial | 2020 |
| Broadwater Hundred Property Management Ltd | Real estate | 2023 |
| Bromham Developments Ltd | Extraterritorial | 2024 |
| Brooks Plumbing & Heating Services Ltd | Construction | 2022 |
| Brookside (Stotfold) Management Company Limited | Households | 1990 |
| Brothers IP Limited | Professional & scientific | 2014 |
| Brown's Antiques, Billiards & Interiors Limited | Other services | 2007 |
| Brownhughes Ltd | Administrative & support | 2018 |
| Brps Consulting Ltd | Professional & scientific | 2021 |
| Brucie Ltd | Construction | 2019 |
| Bryder Properties Limited | Real estate | 2024 |
| BSG Management UK Limited | Administrative & support | 2024 |
| Buildings Maid Clean Ltd | Administrative & support | 2024 |
| Bullet Systems (London) Limited | Information & communication | 1998 |
| Bulman Property Development Limited | Real estate | 2019 |
| Burg Consultants Limited | Professional & scientific | 2021 |
| BUS Stop Mail Order Limited | Wholesale & retail | 1994 |
| Bushmead Community Shop CIC | Wholesale & retail | 2019 |
| Business Orientated Security Services Limited | Information & communication | 2010 |
| Butlers Trees Ltd | Agriculture & fishing | 2020 |
| Bysshe Ltd | Education | 2017 |
| Bywater Plumbing & Heating Limited | Construction | 2010 |
| C & F ENG Limited | Manufacturing | 2016 |
| C R B Utilities Ltd | Construction | 2025 |
| C S a Landscape Limited | Other services | 1998 |
| C T M Property Management Limited | Real estate | 2013 |
| C T P Holdings 2012 Limited | Financial services | 2012 |
| C. S. Torbett Limited | Construction | 2003 |
| C.Green Cost Consultancy Limited | Professional & scientific | 2023 |
| C.R.M Contractors Limited | Construction | 2012 |
| Cabinair Services Limited | Administrative & support | 2006 |
| Cabins (GB) Limited | Professional & scientific | 2013 |
| Cachet Cars Ltd | Transport & logistics | 2006 |
| Cadia Life Limited | Health & social care | 2026 |
| Cadona Creative Limited | Information & communication | 2009 |
| Cadwell Green Residents Management Company Limited | Households | 2007 |
| Caelia Clothing Ltd | Wholesale & retail | 2026 |
| Cafetti Ltd | Hospitality | 2019 |
| Cairoo Coffee Ltd | Manufacturing | 2018 |
| CAL 2020 Limited | Professional & scientific | 2012 |
| Calibration, Maintenance & Repair (Northern) Ltd | Manufacturing | 2019 |
| Calibration,Maintenance & Repair Ltd | Manufacturing | 2003 |
| Calm Property Limited | Construction | 2025 |
| Cambridge & Bury East Limited | Hospitality | 1998 |
| Cambridge Bespoke Limited | Manufacturing | 2025 |
| Cambridge Biomed Ltd | Administrative & support | 2022 |
| Cambridge House Limited | Households | 1985 |
| Cambridge Motorsport Parts Limited | Wholesale & retail | 2006 |
| Campadon Limited | Real estate | 2019 |
| Camper Conversion Specialists Ltd | Wholesale & retail | 2024 |
| Camworq Ltd | Manufacturing | 2016 |
| Canary Wharf & City (Recruitment) Limited | Administrative & support | 2005 |
| Canvin Gunner Holdings Limited | Professional & scientific | 1993 |
| Capital Cabins Limited | Administrative & support | 2011 |
| Capital Lending Solutions Ltd | Financial services | 2026 |
| Car Moove Ltd | Transport & logistics | 2026 |
| Carb-Off! Limited | Manufacturing | 2024 |
| Carbury Ventures Limited | Financial services | 2017 |
| CARE4LIFE Limited | Health & social care | 2014 |
| Caromatherapy Ltd | Manufacturing | 2023 |
| Cashin Projects Ltd | Construction | 2025 |
| Casparr Biosciences Limited | Professional & scientific | 2023 |
| Catskill Law Limited | Professional & scientific | 2010 |
| Causeway Systems Consultants Limited | Information & communication | 1997 |
| Cavendish Court (Biggleswade) Limited | Households | 1986 |
| Cawdor Consulting Ltd | Professional & scientific | 2023 |
| CB Cityskape Ltd | Construction | 2019 |
| CB Cookery School Limited | Wholesale & retail | 2013 |
| CBN Design & Build Limited | Construction | 2022 |
| CC Notary Limited | Professional & scientific | 2026 |
| CE Cleaning Limited | Administrative & support | 2025 |