| CHS (Ryalls Court) Management Limited | Households | 1989 |
| Churchills Dairy & Parlour Services Limited | Agriculture & fishing | 2005 |
| Ciballi Engineering Ltd | Other services | 2019 |
| Ciceron Rentals Limited | Hospitality | 2019 |
| Cifa Alliance Limited | Wholesale & retail | 2026 |
| Cilly Clip Ltd | Wholesale & retail | 2020 |
| CJ Property Investments Group Limited | Real estate | 2020 |
| CJ Windows and Doors Ltd | Manufacturing | 2024 |
| Claire's Cleaning Ltd | Administrative & support | 2015 |
| Classic Golden Barber Ltd | Other services | 2026 |
| Clavis Technologies Limited | Information & communication | 2021 |
| Clear Space (Trowbridge) Limited | Transport & logistics | 2023 |
| Clear Space Holdings Limited | Financial services | 2023 |
| Clear Space Self Storage LLP | | 2018 |
| Clear Space Storage Limited | Other services | 2019 |
| Clerin Limited | Wholesale & retail | 2018 |
| Click & Buy IT Ltd | Wholesale & retail | 2010 |
| Clifton Maybank Estates Limited | Real estate | 2021 |
| CLM Cornwall Limited | Real estate | 2012 |
| Cloverclozen Limited | Real estate | 2003 |
| Cluff Property Managers Limited | Real estate | 2007 |
| CM Electrical (SW) Ltd | Construction | 2026 |
| CMB Group of Healthcare Solutions Ltd | Administrative & support | 2023 |
| Coached by the Couple Ltd | Health & social care | 2024 |
| COAST2COAST Clearance Ltd | Water & waste | 2025 |
| Cochrane Consulting Limited | Information & communication | 1997 |
| Cocopac Limited | Manufacturing | 2008 |
| Cognition Consultancy Services Ltd | Information & communication | 2010 |
| Coles Cross Limited | Professional & scientific | 1998 |
| Collar Craft Ltd | Manufacturing | 2021 |
| Collate Holdings Limited | Real estate | 2020 |
| Collectors Lounge Ltd | Wholesale & retail | 2023 |
| Combat Dollies Fitness Apparel Ltd | Wholesale & retail | 2016 |
| Combi Care and Repair - James Mason Ltd | Construction | 2025 |
| Combi Care and Repair - Ollie Gibson Ltd | Construction | 2025 |
| Combi Care and Repair Ltd | Construction | 2009 |
| Commerce Chief Ltd | Wholesale & retail | 2026 |
| Commerch Ltd | Wholesale & retail | 2021 |
| Commercial Biomass Ltd | Construction | 2016 |
| Commune CC Limited | Wholesale & retail | 2020 |
| Communifit Ltd | Arts & recreation | 2021 |
| Community Transport (South West) Limited | Transport & logistics | 2006 |
| Complete Fitness Coaching Ltd | Wholesale & retail | 2010 |
| Comprep Limited | Other services | 2021 |
| Compton Mews Management Company Limited | Households | 2022 |
| Compton Property Ltd | Real estate | 2019 |
| Concat Group Ltd | Real estate | 2023 |
| Concept Products Limited | Wholesale & retail | 1985 |
| Conkers Property Limited | Real estate | 2020 |
| Consol Southwest Limited | Other services | 2011 |
| Consulting Intermediary Agency Ltd | Wholesale & retail | 2019 |
| Controlled Descent Company Ltd. | Information & communication | 2013 |
| Convoy App Limited | Information & communication | 2025 |
| Cookstream Limited | Wholesale & retail | 2009 |
| Cool Dog UK Ltd | Manufacturing | 2019 |
| Cool Story Limited | Information & communication | 2022 |
| Cooldown Ltd | Hospitality | 2025 |
| Coombe Lake Farms Limited | Agriculture & fishing | 1996 |
| Core Creative Education CIC | Education | 2015 |
| Core Creative Ltd | Professional & scientific | 2005 |
| Cormorant Consulting Ltd | Professional & scientific | 2019 |
| Cornish Connection South Ltd | Wholesale & retail | 2021 |
| Coronation Road Developments Nominee Co Limited | Professional & scientific | 2013 |
| Corr Developments South West Ltd | Construction | 2021 |
| Corsi Construction Ltd | Construction | 2015 |
| Counterpoint Partners Limited | Financial services | 1999 |
| Country Build SWM Limited | Construction | 2016 |
| Country Plate Catering Ltd | Hospitality | 2017 |
| Court Connect Ltd | Professional & scientific | 2025 |
| Court View (South Cadbury) Management Company Limited | Households | 2018 |
| Covodal Tech Limited | Information & communication | 2024 |
| COW to Cone Limited | Manufacturing | 2008 |
| COX & Turner Engineering Ltd | Wholesale & retail | 2015 |
| Craig Building Refurbishments Ltd | Construction | 2026 |
| Craiglea House Management Company Limited | Households | 2005 |
| Cranleigh Taxis Limited | Transport & logistics | 2014 |
| Creative Concrete Ltd | Construction | 2026 |
| Creative Matter London Limited | Extraterritorial | 2017 |
| Creative Simulation Limited | Information & communication | 2017 |
| Crepe House Ltd | Hospitality | 2025 |
| Crepography Ltd | Wholesale & retail | 2020 |
| Crepstars Ltd | Wholesale & retail | 2018 |
| Crewkerne Finance and Consulting Limited | Financial services | 2013 |
| Cristeacompany Limited | Wholesale & retail | 2024 |
| Crop Advisors Limited | Wholesale & retail | 2015 |
| Cross CUT Shredding Ltd | Water & waste | 2015 |
| Crost Limited | Other services | 2018 |
| CRT Media Ltd | Wholesale & retail | 2025 |
| Crystal Classics Auctions Limited | Wholesale & retail | 2017 |
| Crystal Classics Fine Minerals Limited | Mining & quarrying | 2011 |
| CST Property Solutions Ltd | Real estate | 2026 |
| CTC Civils & Utilities Limited | Administrative & support | 2010 |
| Culdany Holdings Limited | Financial services | 2023 |
| Custom Timber Building Limited | Manufacturing | 2000 |
| Cuts & Creps Ltd | Other services | 2018 |
| Cv-Vans.Co.Uk Ltd. | Wholesale & retail | 2010 |
| CVN Interiors Ltd | Construction | 2018 |
| Cxing Paradigms Limited | Other services | 2024 |
| Cyma Limited | Information & communication | 2007 |
| D & F (Yeovil) Limited | Hospitality | 2013 |