| Continuum Recruitment Group Ltd | Administrative & support | 2026 |
| Contour Care Limited | Health & social care | 2022 |
| Contrasting Horizons Limited | Education | 2003 |
| Cook Clinical Research Limited | Professional & scientific | 2008 |
| Cook Industries Ltd | Wholesale & retail | 2014 |
| Cookbay Ltd | Wholesale & retail | 2024 |
| Cooke Motors Ltd | Wholesale & retail | 2022 |
| Coolgamingstuff Ltd | Information & communication | 2024 |
| Coombe House and Cottages Ltd | Real estate | 2016 |
| Coombe House Management Limited | Households | 2023 |
| Cooper's Sister Dog Grooming Ltd | Other services | 2024 |
| Coopersak Ltd | Information & communication | 2014 |
| Copenhagen Court Amenity Limited | Real estate | 2014 |
| Copitol Limited | Construction | 2015 |
| Copleston Consulting Ltd | Information & communication | 2023 |
| Coporate Clinic Energy Limited | Information & communication | 2019 |
| Copp Estates Limited | Real estate | 2024 |
| Coppathorne Developments Ltd | Administrative & support | 2009 |
| Copper Wire Electrics Ltd | Construction | 2018 |
| Copyology Ltd | Professional & scientific | 2014 |
| Cor-Heat Limited | Construction | 2020 |
| Corbyn Mount Management Company (Torquay) Limited | Households | 1987 |
| Cordial Cars Limited | Transport & logistics | 2023 |
| Cordial Transfer Limited | Wholesale & retail | 2025 |
| Core Blue Limited | Information & communication | 2016 |
| Core Compliance Ltd | Construction | 2024 |
| Core Estimating Ltd | Construction | 2024 |
| Core Muscle Ltd | Arts & recreation | 2025 |
| Core Muscle Nutrition Ltd | Wholesale & retail | 2022 |
| Core Plumbing Solutions Ltd | Construction | 2013 |
| Core.Living Architecture Ltd | Construction | 2024 |
| Core.Living Investments Ltd | Construction | 2024 |
| Coreblue (UK) Limited | Information & communication | 2024 |
| Coreblue Holdings Limited | Financial services | 2024 |
| Corelli House Management Company Limited | Real estate | 2007 |
| Coretechnics Ltd | Information & communication | 2023 |
| Corey Becks Ltd | Health & social care | 2019 |
| Corisande Pavilions Management Company Limited | Households | 2014 |
| Corner Flag Property Solutions Limited | Real estate | 2015 |
| Cornerstone Business Development Ltd | Professional & scientific | 2026 |
| Cornerstone Homes (Southern) Limited | Construction | 2021 |
| Cornerstone Homes (SW) Limited | Financial services | 2004 |
| Cornerstone Homes Southwest Ltd | Construction | 2025 |
| Cornfield Commercial Ltd | Real estate | 2025 |
| Cornflower Kitchens & Bathrooms Limited | Construction | 2024 |
| Cornish Catch Limited | Wholesale & retail | 2006 |
| Cornish Grab Co Ltd | Water & waste | 2024 |
| Cornish Interiors Ltd | Other services | 2013 |
| Cornish Potatoes Limited | Financial services | 2010 |
| Cornish Scrumpy Company Limited | Manufacturing | 1979 |
| Cornish Scrumpy Holdings Limited | Manufacturing | 2001 |
| Cornwall & Devon Interiors Limited | Construction | 2006 |
| Cornwall Car Centre Ltd | Wholesale & retail | 2004 |
| Cornwall County Fasteners Ltd | Wholesale & retail | 2024 |
| Cornwall Estates (Padstow) Limited | Real estate | 2017 |
| Cornwall Gate Sports Bar Ltd | Hospitality | 2019 |
| Cornwall Leisure Activities Limited | Arts & recreation | 2007 |
| Cornwall Scooter Centre Ltd | Wholesale & retail | 2017 |
| Cornwood Estates Limited | Real estate | 2012 |
| Coromandel Holdings Ltd | Professional & scientific | 2017 |
| Corporate & Commercial Ltd | Construction | 2009 |
| Corporate Bond and Build Limited | Arts & recreation | 2016 |
| Corporatura SW Construction Ltd | Construction | 2025 |
| Corporatura SW Ltd | Professional & scientific | 2023 |
| Cors Holdings Ltd | Arts & recreation | 2025 |
| COSDA2SHOP Ltd | Hospitality | 2023 |
| Cosette Co. Ltd | Other services | 2019 |
| Cosmic Foods SW Ltd | Hospitality | 2023 |
| Cosmic Kitchen Limited | Hospitality | 2020 |
| Cosmic Property Ltd | Real estate | 2024 |
| Cosmic Rentals Ltd | Real estate | 2024 |
| Cosmic Sessions Ltd | Hospitality | 2023 |
| Cosy House Relocations Ltd | Real estate | 2023 |
| Cosy Oak Ltd | Real estate | 2022 |
| Cosy Spool Ltd | Information & communication | 2025 |
| Cotswold Data Cabling Ltd | Construction | 2012 |
| Cotura Ltd | Information & communication | 2026 |
| Countryside Decorators Limited | Construction | 2023 |
| Countrywide Electrical Testing Ltd | Construction | 2017 |
| County Chiropractic Plymouth Limited | Health & social care | 2008 |
| County Fasteners Limited | Wholesale & retail | 2009 |
| County Garage (Barnstaple) Limited | Extraterritorial | 1965 |
| County Grounds Gritting Limited | Administrative & support | 2026 |
| County Grounds Group Limited | Administrative & support | 2026 |
| County Grounds Landscapes Limited | Extraterritorial | 2014 |
| County Grounds Maintenance Limited | Other services | 2005 |
| County Wide Services (SW) Limited | Construction | 2021 |
| Courierforce Logistics Limited | Transport & logistics | 2007 |
| Court 6 Developments Limited | Real estate | 2025 |
| Court Gate Services Limited | Health & social care | 2002 |
| Court Steps Ltd | Health & social care | 2026 |
| Courtenay Dental Ltd | Health & social care | 2012 |
| Cove Consultancy Ltd | Professional & scientific | 2026 |
| Cove Head CIC | Arts & recreation | 2019 |
| Cove Meadow Management Company Limited | Households | 1992 |
| Cove Property Services Limited | Construction | 2006 |
| Covedene Limited | Households | 1988 |
| Covell Consulting Limited | Professional & scientific | 2023 |
| Coverack Headland Limited | Households | 1992 |
| Coverley Transport Ltd | Transport & logistics | 2025 |