| Chapsmith Services Ltd. | Water & waste | 2006 |
| Charity Lifeline CIC | Wholesale & retail | 2013 |
| Charlie Buffett Ltd | Real estate | 2021 |
| Charlie Motors Ltd | Wholesale & retail | 2025 |
| Charming Properties Limited | Real estate | 2006 |
| Charpak Limited | Manufacturing | 1981 |
| Chatteris Turbine Limited | Energy | 2014 |
| Chekusi Limited | Health & social care | 2015 |
| Chester (1995) Limited | Extraterritorial | 1906 |
| Chestnut Farm House Creations Limited | Hospitality | 2013 |
| Chestnut Tree Counselling and Psychotherapy Ltd. | Administrative & support | 2021 |
| Chic Ecigarettes Ltd | Wholesale & retail | 2016 |
| Chigx Limited | Administrative & support | 2026 |
| Chillingworth Limited | Construction | 2003 |
| Chiltern Home Developments Limited | Manufacturing | 1993 |
| Chimes Place Management Company Limited | Households | 2007 |
| Chimp Tune Racing Limited | Manufacturing | 2005 |
| China 636 Limited | Hospitality | 2025 |
| Chiq Appliances Limited | Wholesale & retail | 2024 |
| Chloe Nails Huntingdon Ltd | Other services | 2026 |
| Chozha Retail Ltd | Wholesale & retail | 2025 |
| Chris Edwards (Farrier) Limited | Other services | 2006 |
| Chris IAN Chapman Plumbing & Heating Ltd | Construction | 2018 |
| Chris Twitty Services Ltd | Transport & logistics | 2019 |
| Christopher Millen Limited | Extraterritorial | 2016 |
| Chromalock Limited | Manufacturing | 1977 |
| Church Electrical Contractors Ltd | Construction | 2021 |
| Church Road Warboys Limited | Construction | 2019 |
| Churchgates Land Family Business Limited | Professional & scientific | 2017 |
| Churchill Cricket BAT Repairs Ltd | Manufacturing | 2024 |
| Churchman Holdings Ltd | Real estate | 2021 |
| Ciconi Limited | Transport & logistics | 1997 |
| Cinelanguage Ltd. | Arts & recreation | 2014 |
| Circuit Solutions (Cambridge) Limited | Manufacturing | 1999 |
| Circuit Solutions Holdings Limited | Financial services | 2020 |
| Circus Generations Ltd | Education | 2024 |
| Citrox Biosciences Limited | Health & social care | 2006 |
| City Road Properties (Chester) Limited | Construction | 2000 |
| Civil Parteners Ltd | Construction | 2026 |
| Civil Safety Holdings Ltd | Financial services | 2023 |
| Civil Safety Training & Rescue Limited | Construction | 2018 |
| CJ Landscapes and Buildiing Ltd | Construction | 2023 |
| CJH Investments Ltd | Financial services | 2023 |
| CJM Draughting Limited | Professional & scientific | 1998 |
| CJT Property Solutions Ltd | Real estate | 2021 |
| CK Scaffolding Solutions Limited | Construction | 2020 |
| CKC Haulage Ltd | Transport & logistics | 2025 |
| CKC Investments Ltd | Real estate | 2021 |
| Clan Astra Ltd | Hospitality | 2019 |
| Clan Harper Holdings Ltd | Financial services | 2025 |
| Claraty Consulting Limited | Administrative & support | 2013 |
| Clara’S Enchanted World Ltd | Manufacturing | 2025 |
| Clarence House Day Nurseries Ltd | Health & social care | 1999 |
| Clarendon Investment Group Limited | Financial services | 2025 |
| Clares Driving School Ltd | Education | 2025 |
| Clarke and Sons Removals Limited | Transport & logistics | 2024 |
| Classic Voyages Limited | Extraterritorial | 2010 |
| Claytonford Ltd. | Construction | 2011 |
| Clean Genie Peterborough Limited | Administrative & support | 2017 |
| Clear Horizons Cambridge Ltd | Administrative & support | 2014 |
| Clear Moon Fast Food Ltd | Hospitality | 2019 |
| Clearly Essential Ltd | Professional & scientific | 2021 |
| Clearview Crest Holdings Limited | Real estate | 2026 |
| Clemency JF Limited | Real estate | 2025 |
| Clever Product Innovation Ltd | Extraterritorial | 2021 |
| CLF Boxwise Limited | Wholesale & retail | 1974 |
| CLF Group Limited | Financial services | 2024 |
| CLF Limited | Professional & scientific | 2001 |
| CLF Manufacturing Limited | Real estate | 1981 |
| CLF Packaging Limited | Extraterritorial | 2026 |
| Clintex Limited | Administrative & support | 1996 |
| Clive Dodson Thatchers Limited | Construction | 2010 |
| Clog Holdings Limited | Real estate | 2017 |
| Cloverfield Number 2 Residents Association Limited | Households | 1991 |
| CLR Wireless Ltd | Information & communication | 2024 |
| Club Ace Ltd | Wholesale & retail | 2025 |
| Club Toolkit Limited | Information & communication | 2025 |
| Clydes Trading Limited | Wholesale & retail | 2026 |
| CM Release Management Ltd | Professional & scientific | 2026 |
| CMD Kitchens and Bathrooms Limited | Construction | 2010 |
| CML Contract Cleaning Services Limited | Manufacturing | 2017 |
| Cmpny B Limited | Professional & scientific | 2019 |
| Cmtm Transport Ltd | Wholesale & retail | 2024 |
| CNO Computers Ltd | Information & communication | 2026 |
| Coastal and City Management (Pubs) Limited | Hospitality | 2025 |
| Cobalt Carillon Limited | Hospitality | 2024 |
| Code Craft Systems Limited | Construction | 2023 |
| Code Style Ltd | Information & communication | 2021 |
| Coffeeonme Ltd | Education | 2025 |
| Cogdem | Other services | 1999 |
| Cognivanta Limited | Wholesale & retail | 2026 |
| Cold Link Limited | Manufacturing | 1996 |
| Coldwater Seafood (UK) Limited | Extraterritorial | 1996 |
| Coles Conservation Architects Limited | Professional & scientific | 2023 |
| Coles Property Investments Limited | Real estate | 2025 |
| Colette Guinea Ltd | Professional & scientific | 2023 |
| Colin Barson Electrical Services Ltd. | Construction | 2014 |
| Colin Read & Sons Limited | Construction | 2005 |
| Collective Context Ltd | Professional & scientific | 2021 |
| Collins Co Holdings Limited | Financial services | 2025 |