| CC Tours & Consulting Ltd | Administrative & support | 2024 |
| CCA Global Imports Ltd | Transport & logistics | 2022 |
| CCC Lincs Ltd | Professional & scientific | 2024 |
| Ccsma Ltd | Arts & recreation | 2023 |
| Cdls . Connect. Develop. Learn. Succeed. Ltd | Administrative & support | 2026 |
| Centaurus Events Limited | Administrative & support | 2005 |
| Ceylanim Ltd | Other services | 2016 |
| Ceylon Gems and Jewellery Ltd | Wholesale & retail | 2015 |
| CH Living Limited | Households | 2023 |
| Chapel Garth Ltd | Real estate | 2025 |
| Chapel House Group Limited | Financial services | 2014 |
| Chapel House Residential Property Limited | Real estate | 2024 |
| Charlie Hart Health and Fitness Limited | Arts & recreation | 2025 |
| Cherished Cottages Ltd | Real estate | 2014 |
| Cherry Tree Cornwall Limited | Construction | 2025 |
| Cherry Tree Laundry Solutions Ltd | Other services | 2013 |
| Cherrytree Machines Limited | Wholesale & retail | 2013 |
| Chilati Drinks Ltd | Wholesale & retail | 2021 |
| Choice Homes Residential Sales & Lettings Ltd | Real estate | 2010 |
| Chris Kennett Consulting Limited | Transport & logistics | 2020 |
| Church Mews (Moston) Management Company Limited | Hospitality | 2005 |
| Churchward County Trust Ltd | Manufacturing | 2018 |
| CHX Limited | Professional & scientific | 2012 |
| Chymill Limited | Real estate | 2013 |
| Chywartha Management Services Ltd | Professional & scientific | 2020 |
| Ciho Limited | Hospitality | 2024 |
| Cinquelles Limited | Administrative & support | 1994 |
| CJ Holdings (ST Ives) Limited | Construction | 2019 |
| Clare Pond Property Limited | Administrative & support | 2019 |
| Clark Drive Procurement Ltd | Professional & scientific | 2025 |
| Clarke's Construction (Cambridge) Limited | Construction | 2012 |
| Clean UP the Internet | Other services | 2019 |
| Clear R US Limited | Administrative & support | 2025 |
| Clearer Hearing Limited | Wholesale & retail | 2001 |
| Clearview Installations Limited | Wholesale & retail | 2007 |
| Clenstar Properties Limited | Real estate | 2023 |
| Clenzair Ltd | Wholesale & retail | 2020 |
| Clifton and Burton Group Limited | Financial services | 1999 |
| Clifton Engineering and Polymers Limited | Professional & scientific | 2016 |
| Clifton Polyurethane Limited | Professional & scientific | 2016 |
| Clifton Products Limited | Professional & scientific | 2016 |
| Clifton Rollers Limited | Professional & scientific | 2016 |
| Clifton Rubber Company Limited | Manufacturing | 1973 |
| Clinical Development Resources Limited | Professional & scientific | 2021 |
| Clinical Pet Care Holdings Limited | Professional & scientific | 2022 |
| Clinton Flat Management Limited | Households | 2005 |
| Cloudlight Ltd | Hospitality | 2024 |
| Cloudplex Solutions Ltd | Information & communication | 2024 |
| CM Event Management Limited | Other services | 2014 |
| CMK Tax Associates Limited | Professional & scientific | 2010 |
| Coalesce Medica Limited | Professional & scientific | 2022 |
| Coastal Cars ST Ives Ltd | Transport & logistics | 2024 |
| Coastal Park Homes (ST Ives) Limited | Construction | 2021 |
| CODE57 Limited | Information & communication | 2019 |
| Colmel Limited | Professional & scientific | 2013 |
| Colorweigh Limited | Extraterritorial | 2019 |
| Colour-Fit Ltd | Health & social care | 2016 |
| Commercial Vehicle Fleet Support Ltd | Manufacturing | 2023 |
| Complete Home Developments Limited | Construction | 2020 |
| Compliance Fire Safety Limited | Professional & scientific | 2017 |
| Concero Limited | Information & communication | 1995 |
| Concise IP Limited | Administrative & support | 2010 |
| Concrete Rose Collective CIC | Education | 2020 |
| Connected Nationwide Ltd | Professional & scientific | 2023 |
| Connection Partnership Limited | Construction | 1996 |
| Consolidated Mines Ltd | Mining & quarrying | 2025 |
| Consultancy DMH Ltd | Professional & scientific | 2013 |
| Cook and Collins Property Services Ltd | Construction | 2020 |
| Cordic CG Ltd | Financial services | 2022 |
| Cordic Group Limited | Financial services | 2018 |
| Cordyline Croft Management Limited | Households | 2016 |
| Corineus Media Ltd | Professional & scientific | 2020 |
| Cornhill Search to Search Limited | Administrative & support | 2012 |
| Cornico Foods Service Ltd | Wholesale & retail | 2023 |
| Cornish Crawfish CIC | Wholesale & retail | 2025 |
| Cornish Peninsula Limited | Hospitality | 2026 |
| Cornish Tech House Ltd | Wholesale & retail | 2023 |
| Cornwall Cranes Ltd | Construction | 2022 |
| Cornwall House and Home Developments Ltd | Construction | 2025 |
| Cornwall School of Painting Limited | Education | 2022 |
| Cornwall TIN Limited | Mining & quarrying | 2015 |
| Cornwall VW Wedding Hire Limited | Transport & logistics | 2014 |
| Cornwallis Care Properties Limited | Health & social care | 2016 |
| Cornwallis Care Services Ltd. | Health & social care | 1996 |
| Cornwallspice Limited | Hospitality | 2022 |
| Corporate Games Holdings Ltd | Administrative & support | 2024 |
| Corporate Games Worldwide Ltd | Administrative & support | 2024 |
| Cottage Holidays Kernow Limited | Real estate | 2015 |
| Couchman and Leafe Limited | Professional & scientific | 2001 |
| Cousin Jacks Ltd | Hospitality | 2023 |
| Cousins Fine Art Limited | Wholesale & retail | 2021 |
| Cove Equestrian Ltd | Wholesale & retail | 2021 |
| Covered Outdoor Solutions Limited | Extraterritorial | 2011 |
| CR2 Trading Ltd | Information & communication | 2019 |
| Crane Rail Solutions Limited | Professional & scientific | 2024 |
| Create N CUT Services Limited | Manufacturing | 2025 |
| Crepes by the Coast Ltd | Hospitality | 2026 |
| Cressia Limited | Real estate | 2016 |
| Crestbridge Consulting Ltd | Administrative & support | 2026 |
| Croesus Financial Services Limited | Financial services | 2002 |