| Brightmere Group Ltd | Financial services | 2020 |
| Brogan Consulting Ltd | Information & communication | 2018 |
| Brown Sugar Design Ltd | Professional & scientific | 2015 |
| Bryni EHF Limited | Administrative & support | 2011 |
| Bsec Design Limited | Construction | 1997 |
| BSL Assets Ltd | Real estate | 2017 |
| Bucks Treatment Services Ltd | Water & waste | 2018 |
| Build Arcane Ltd | Information & communication | 2025 |
| Bullet and Bone Limited | Wholesale & retail | 2017 |
| Buntings Garden Maintenance Ltd | Administrative & support | 2014 |
| Burley Plumbing and Heating Ltd | Construction | 2024 |
| Burns Acquisitions Limited | Real estate | 2001 |
| Business Analysis & Evaluation Consultation Ltd | Information & communication | 2014 |
| Butterfly Medical Consultancy Ltd | Professional & scientific | 2010 |
| Butterfly Print & Design Ltd | Administrative & support | 2009 |
| BW Ecommerce Limited | Wholesale & retail | 2017 |
| BW Services Limited | Information & communication | 2026 |
| BY Financial Services Limited | Administrative & support | 2020 |
| Byrne Fabrication Ltd | Manufacturing | 2025 |
| Byte Flurry Limited | Information & communication | 2024 |
| C & J Facilities Limited | Construction | 2011 |
| C & J Marketing Limited | Information & communication | 2018 |
| C D Lane Contractors Limited | Construction | 2002 |
| C Knight Dance Development Limited | Education | 2025 |
| C M Supplies (Food) Limited | Wholesale & retail | 2009 |
| C Sense ISC Limited | Information & communication | 2023 |
| C&H Dental Ltd | Health & social care | 2021 |
| C.B Services (MEP) Ltd | Professional & scientific | 2019 |
| C.D. Lane Holdings Ltd. | Administrative & support | 2007 |
| C.E.Harrison Ltd | Professional & scientific | 2018 |
| Cabin Crew Records Ltd | Wholesale & retail | 2025 |
| Cactus Specialist UK Ltd | Agriculture & fishing | 2024 |
| CAE First Limited | Information & communication | 2017 |
| Caffeine & Cars Ltd | Wholesale & retail | 2023 |
| Cairngorm Wilderness Retreats Limited | Hospitality | 2017 |
| Calisto NOW Ltd | Professional & scientific | 2026 |
| Call Logging Limited | Information & communication | 2023 |
| Calland Telecommunications Solutions Ltd | Professional & scientific | 2019 |
| CAM (INT) Associates Ltd | Professional & scientific | 2022 |
| Camargue Capital Management LLP | | 2007 |
| Cambase Limited | Professional & scientific | 2024 |
| Cameron Greer Limited | Health & social care | 2018 |
| Camops Ltd | Professional & scientific | 2018 |
| Campbell House (Twickenham) Limited | Households | 2005 |
| Canbury Associates Limited | Professional & scientific | 2023 |
| Cannon Despatch Limited | Transport & logistics | 2012 |
| Cannon VCC Limited | Professional & scientific | 2022 |
| Capital & Continental Holdings Limited | Professional & scientific | 1972 |
| Cardinal Data Solutions Limited | Information & communication | 2002 |
| Carlotte Wubben-Moy Limited | Arts & recreation | 2021 |
| Carmenta Consulting Ltd | Professional & scientific | 2018 |
| Carnaby Gaming Machines Limited | Manufacturing | 1997 |
| Carrera Revell UK Ltd. | Manufacturing | 2019 |
| Carrier Labs Ltd | Information & communication | 2022 |
| Caryatid Limited | Professional & scientific | 1996 |
| Case Catering Limited | Hospitality | 2025 |
| Case Land & Property Ltd | Construction | 2018 |
| Cashisking Limited | Professional & scientific | 2010 |
| Casino Consultants UK Ltd | Professional & scientific | 2002 |
| Castlesque Hospitality Limited | Hospitality | 2017 |
| CCE Project Partners Limited | Professional & scientific | 2018 |
| Cdrl Limited | Real estate | 2019 |
| Celeste Artisans Limited | Wholesale & retail | 2021 |
| Centre for Men's Health Limited | Health & social care | 1995 |
| Centurion Technologies Limited | Extraterritorial | 2015 |
| Certyl UK Limited | Professional & scientific | 2019 |
| Cerulus Ltd | Information & communication | 2018 |
| Cevc Ltd | Extraterritorial | 2024 |
| Chahal Capital Limited | Information & communication | 2023 |
| Chalkstream Limited | Professional & scientific | 2012 |
| Changing Stages Ltd | Education | 2025 |
| Channel Assist Limited | Professional & scientific | 2007 |
| Chapmans Management Ltd | Real estate | 2020 |
| Character Cottages Ltd. | Professional & scientific | 2000 |
| Character Coving Limited | Wholesale & retail | 2006 |
| Charcon Financial Ltd | Professional & scientific | 2018 |
| Charles Tiles Ltd | Other services | 2024 |
| Charlesgate Design & Build Ltd | Construction | 2014 |
| Charm Event Directors Limited | Administrative & support | 2014 |
| Chathom Limited | Professional & scientific | 2016 |
| CHE Sara Sara Limited | Arts & recreation | 1999 |
| Cheeni MOU Limited | Hospitality | 2025 |
| Chesham Construction Company Limited | Construction | 1993 |
| Chicken Coco Ltd | Hospitality | 2025 |
| Children's Parties Ltd | Arts & recreation | 2021 |
| Chilly Interiors Ltd | Construction | 2012 |
| Chiltern Chimneys Ltd | Extraterritorial | 2011 |
| Chiltern Engineering Solutions Limited | Manufacturing | 2012 |
| Chiltern Fish and Game Ltd | Wholesale & retail | 2010 |
| Chiltern Hills Mineral Water Limited | Professional & scientific | 1970 |
| Chiltern Kitchens Limited | Construction | 2003 |
| Chiltern Motors (B.C) Limited | Wholesale & retail | 2003 |
| Chiltern Rentals Limited | Real estate | 2015 |
| Chilton Trading Ltd | Information & communication | 2018 |
| Chimetown Property Management Limited | Households | 1990 |
| Chimp Brain Limited | Information & communication | 2021 |
| Chithurst Limited | Professional & scientific | 2020 |
| Chivery Hall Farm Limited | Agriculture & fishing | 2002 |
| Chris Mcgrath Limited | Information & communication | 2008 |
| Chris Smith Haulage Limited | Transport & logistics | 1998 |