| Centrax Holdings Limited | Professional & scientific | 2006 |
| Centrax Power Projects Limited | Manufacturing | 2007 |
| Centrax Technologies Limited | Extraterritorial | 1983 |
| Centreline Consultants Ltd | | 1989 |
| Certus Technology Associates Limited | Information & communication | 2000 |
| Chancery Asset Management (Exeter) | | 2006 |
| Chapman Electrical (South West) Limited | Construction | 2003 |
| Chard Digital Print Ltd. | Manufacturing | 2006 |
| Charles Armitage Independent Limited | Other services | 2004 |
| Charles Gray (Property Holdings) Limited | Real estate | 2007 |
| Charleston Estates Limited | Real estate | 1985 |
| Chelston Electrical Services Limited | Wholesale & retail | 2003 |
| Cherry Hudson Ltd | Financial services | 2024 |
| Chez Domaine (France) Limited | Households | 2004 |
| Chiltern Casting Company Limited | Extraterritorial | 2010 |
| China Blue (Devon) Limited | Manufacturing | 1981 |
| Chinese Acupuncture and Herbal Medicine Ltd | Health & social care | 2020 |
| Chinese Acupuncture Clinic Limited | Health & social care | 2003 |
| Chinta Ltd | Transport & logistics | 2014 |
| Chiron Resources (Operations) Limited | Administrative & support | 2001 |
| Chris Warren Construction Limited | Construction | 2004 |
| Christopher Earl Properties Limited | Real estate | 1989 |
| Cine Power International Limited | Manufacturing | 1989 |
| Cisok Ltd | Transport & logistics | 2018 |
| City of Exeter Y.M.C.A. | Real estate | 1989 |
| Clarity North West Ltd. | Wholesale & retail | 2010 |
| Clark Hire (Torbay) Limited | | 1979 |
| Clegg & Shortman Asphalt Co. Limited | Construction | 1975 |
| Clennon Court Housing Association Limited | Households | 1977 |
| Clifton Heating & Kitchens Ltd | Construction | 2005 |
| Clinnick Motors Limited | Wholesale & retail | 2007 |
| Clover Cars (Barnstaple) Limited | Wholesale & retail | 2002 |
| Clowance Owners Club Limited | Hospitality | 1984 |
| CM Engineering Components Limited | Manufacturing | 2000 |
| CM Investment Properties Limited | Construction | 2006 |
| CMC Logistics (South West) Limited | Transport & logistics | 2006 |
| Coastal Care Homes Limited | Health & social care | 1999 |
| Coates & Co. (Plymouth) Limited | Manufacturing | 1996 |
| Cobblers & Keys SW Ltd | Other services | 2004 |
| Cockman Builders Limited | Construction | 2003 |
| Cocoba Cafes Limited | Hospitality | 2025 |
| Coggins Developments Limited | Wholesale & retail | 1989 |
| Colaspro Limited | Information & communication | 1999 |
| Coleweave Limited | | 1979 |
| Colgor Properties Limited | Real estate | 1987 |
| Colin Hardy & Co. Limited | Financial services | 1976 |
| Colton Brand Limited | Construction | 2007 |
| Coly Vale Holiday Park Limited | Hospitality | 2003 |
| Colyford Butchers Limited | Wholesale & retail | 2002 |
| Colyton Garage Limited | Wholesale & retail | 2002 |
| Com'In Diffusion Limited | Information & communication | 1998 |
| Compass Contractor Services Ltd | Administrative & support | 2017 |
| Compensation Helpline Ltd | Administrative & support | 2006 |
| Complete Computing SW Limited | Wholesale & retail | 2004 |
| Complete Home Solutions Limited | | 2004 |
| Consult a LOT Limited | Professional & scientific | 2006 |
| Coombeshead Limited | Agriculture & fishing | 2005 |
| Copleston House Limited | Agriculture & fishing | 2006 |
| Coppers Investments LLP | | 2025 |
| Corin Homes Limited | Construction | 2004 |
| Corner Close Management Company | Households | 2008 |
| Corner Oaks Limited | Real estate | 2002 |
| Corvette Management (Dawlish) Limited | Households | 1979 |
| Cosdon Limited | Real estate | 2004 |
| Country Cottage Bakery Limited | Wholesale & retail | 2003 |
| Country Hostelries (R.D. Yates) Limited | | 1959 |
| Cowick Street Ltd | Professional & scientific | 2002 |
| Craftedlogic.Net Ltd. | Information & communication | 2000 |
| Cranford Sports Club Limited | Arts & recreation | 1992 |
| Creative Environments Limited | Construction | 2003 |
| Credence Care Ltd | Other services | 2008 |
| Credible Data Limited | Information & communication | 1998 |
| Crediton Commercials Limited | Wholesale & retail | 2003 |
| Creedy Carver Ducks Limited | Agriculture & fishing | 2003 |
| Creedy Park Management Limited | Households | 1978 |
| Crescent (Plymouth) Limited(The) | Households | 1961 |
| Cress Water Ltd. | Water & waste | 1999 |
| Crest Hill Consultancy Limited | Information & communication | 1998 |
| Cromwell Motor Bodies Limited | | 1961 |
| Cross Park Management Company (Holsworthy) Limited | Administrative & support | 2003 |
| Culm Valley Pet Cremation Ltd | Other services | 2020 |
| Cupine Trading Limited | Construction | 2000 |
| Curium Limited | Real estate | 1981 |
| Customercentric Selling Europe Ltd | Administrative & support | 2008 |
| Cygnet Care (Devon) Limited | Health & social care | 2006 |
| Cygnus Education Limited | Education | 1996 |
| Cyprus Road Management Company (Exmouth) Limited | Households | 1984 |
| Cysec Consultants Limited | Information & communication | 2023 |
| Cytometrics Limited | Manufacturing | 2004 |
| D & D Logistics Limited | Wholesale & retail | 2002 |
| D 'N' D Services Limited | Manufacturing | 1992 |
| D C N Cleaning Services Limited | Administrative & support | 2002 |
| D F Bryan Ltd | Construction | 2003 |
| D J Smale Carpentry Ltd | Construction | 2007 |
| D S a Design Services Ltd | Construction | 1999 |
| D+C Electrics Limited | Manufacturing | 2005 |
| D.D. Electrical Engineering Limited | Construction | 2005 |
| D.J. Blackmore Ltd | Construction | 1997 |
| D.K.W. COX & Co. Limited | Agriculture & fishing | 1972 |
| D.P.E. Transport Limited | Transport & logistics | 2005 |