| Cann Lodge Residents Society Limited | Households | 1984 |
| Cannon Court Management Company (Bridgwater) Limited | Households | 2007 |
| Cantelo Nurseries Limited | Financial services | 1987 |
| Canton Night Limited | Hospitality | 2024 |
| Cantycrew Ltd | Financial services | 2025 |
| Capital Aerial Solutions Limited | Information & communication | 2017 |
| Capital International Investments Limited | Financial services | 2014 |
| Capland Court (Hatch Beauchamp) Residents Management Company Limited | Households | 1989 |
| Capone City Entertainment Ltd | Arts & recreation | 2019 |
| Capstick Brothers Limited | Hospitality | 2021 |
| Capstick Capital Ltd | Real estate | 2025 |
| Capstone Home Limited | Other services | 2002 |
| Caralex Recruitment Limited | Administrative & support | 2021 |
| CARAVANS2LOGCABINS Limited | Construction | 2025 |
| Caravantastic Ltd | Administrative & support | 2017 |
| Carbonxilo Limited | Manufacturing | 2023 |
| Cardmania Limited | Wholesale & retail | 2024 |
| Cardrome (UK) Limited | Extraterritorial | 1998 |
| Cardsmill Dairy Limited | Agriculture & fishing | 2025 |
| Cardstream Holdings Limited | Information & communication | 2017 |
| Cardstream International Limited | Information & communication | 1999 |
| Cardstream Limited | Information & communication | 1999 |
| Cardstream Partners Africa Limited | Information & communication | 2018 |
| Cardstream Partners America Limited | Information & communication | 2016 |
| Cardstream Partners Asia Limited | Information & communication | 2015 |
| Cardstream Partners Europe Limited | Information & communication | 2015 |
| Care & I Ltd | Health & social care | 2019 |
| Careervantageuk Ltd | Administrative & support | 2015 |
| Caremate 247 Limited | Administrative & support | 2024 |
| Carewater Limited | Professional & scientific | 1994 |
| Carfty Canvas Limited | Health & social care | 2024 |
| Caringsmart Ltd | Health & social care | 2023 |
| Carl's Cleaning Services (Somerset) Ltd | Administrative & support | 2010 |
| Carnival Sign and Digital Limited | Other services | 2022 |
| Carol Adcock Ltd | Real estate | 2020 |
| Carol Carpenter Training Limited | Professional & scientific | 2001 |
| Carol Property Investments Limited | Real estate | 2025 |
| Carole Walker Media Limited | Professional & scientific | 2023 |
| Caroline Nixon Education Ltd | Real estate | 2015 |
| Carpathian Consultancy Ltd | Professional & scientific | 2024 |
| Carpenters Signature Estates Ltd | Real estate | 2024 |
| Carpenters Signature Living Ltd | Real estate | 2022 |
| Carpets R US Ltd | Wholesale & retail | 2023 |
| Carrick Mill (Topsham) Management Company Limited | Households | 2021 |
| Carrington Capital Limited | Information & communication | 2025 |
| Carrots Farm Management Company Limited | Households | 2022 |
| Carslake Tea Company Limited | Hospitality | 2013 |
| Carter Curtis Properties Ltd | Real estate | 2021 |
| Carter Robinson Limited | Financial services | 2017 |
| Carterton Investments Limited | Real estate | 2017 |
| Cartgate Holdings Limited | Construction | 2017 |
| Cartgate Park Management Company Limited | Construction | 2020 |
| Cartref Homeowners Limited | Households | 2013 |
| Cartridge Line Exeter Ltd | Information & communication | 2005 |
| Cartridge Line Ltd | Wholesale & retail | 2007 |
| Carvey Ventures Limited | Real estate | 2026 |
| Casa Champions Limited | Real estate | 2020 |
| Casby & Co Ltd | Financial services | 2025 |
| Caseyare Consulting Limited | Professional & scientific | 2021 |
| Cash Control Machines (South West) Limited | Other services | 1980 |
| Cassis Limited | Professional & scientific | 2012 |
| Castelan Furniture Care Limited | Extraterritorial | 2011 |
| Castelan Premier Care Limited | Extraterritorial | 2011 |
| Castelijns & Swaans LLP | | 2015 |
| Castle Business Units Limited | Real estate | 2014 |
| Castle Fields (Dunster) Management Company Limited | Real estate | 2015 |
| Castle Grove Management Company Limited | Households | 2020 |
| Castle Hotel (Taunton) Limited(The) | Hospitality | 1959 |
| Castle KC Limited | Financial services | 2022 |
| Castle Street House Limited | Hospitality | 2018 |
| Castle Technical Solutions Limited | Manufacturing | 2015 |
| Castle-Moate Mapping Solutions Ltd | Wholesale & retail | 2019 |
| Castletown Trading Company Ltd. | Extraterritorial | 2000 |
| Cat Companies Ltd | Information & communication | 2024 |
| Catalys-Ability C.I.C. | Health & social care | 2020 |
| Catherine Bunning Beauty Ltd | Other services | 2022 |
| Catherine Court Dentistry Ltd | Health & social care | 2012 |
| Catherine Richardson Associates Limited | Financial services | 2005 |
| Caton Holdings | Professional & scientific | 2024 |
| Cautela Consultancy Limited | Professional & scientific | 2025 |
| Cavaghan Homes Limited | Real estate | 2021 |
| Cave Veterinary Services Ltd | Real estate | 2016 |
| Cavill and Sons Limited | Agriculture & fishing | 2011 |
| Cavill Nhtv Limited | Financial services | 2025 |
| Caving Services Limited | Arts & recreation | 2008 |
| CAZ Bar Ltd | Hospitality | 2012 |
| CBH Investments Ltd | Real estate | 2017 |
| CBW Taunton Limited | Financial services | 2012 |
| CBZ Trans Ltd | Transport & logistics | 2022 |
| CC Compleet LLP | | 2014 |
| CC Hair & Beauty Bar Ltd | Other services | 2022 |
| CC Payfac Limited | Information & communication | 2023 |
| CC Resources Limited | Information & communication | 2023 |
| CCG Enterprises Limited | Financial services | 2019 |
| Ccge Parasol Limited | Financial services | 2020 |
| Ccge Parasol Trustee Limited | Extraterritorial | 2026 |
| CCW Civils Limited | Construction | 2017 |
| CDA Travel Planners Ltd | Administrative & support | 2023 |
| CDD Healthcare Staffing Ltd | Health & social care | 2022 |
| CE Plumbing and Heating Limited | Construction | 2009 |