| Compassionate UK CIC | Education | 2025 |
| Complete Connectrix Electrical Ltd | Construction | 2022 |
| Complete Electricians Ltd | Construction | 2018 |
| Complete Infrastructure Limited | Construction | 2023 |
| Complete Infrastructure Services Ltd | Real estate | 2025 |
| Complete Professional Guidance Limited | Professional & scientific | 2008 |
| Computing Cubed Limited | Administrative & support | 2006 |
| Concept Refrigeration Limited | Construction | 1990 |
| CONCEPTS4FUTURE INT. Limited | Professional & scientific | 2009 |
| Concerts in the West | Arts & recreation | 2010 |
| Concordia Bath Management Company Limited | Households | 2006 |
| Condon Drew Associates Ltd | Information & communication | 2016 |
| Condon Transport Ltd | Information & communication | 2023 |
| Confident Orthodontics Limited | Health & social care | 2012 |
| Confydr Limited | Professional & scientific | 2025 |
| Conibear Bros Limited | Wholesale & retail | 2002 |
| Coniston Property Limited | Construction | 2022 |
| Connectable SW Ltd | Information & communication | 2020 |
| Connected Abodes Ltd | Construction | 2022 |
| Connecting Commerce Limited | Information & communication | 2012 |
| Connective Logic Systems Ltd. | Information & communication | 1997 |
| Conquest Builders Ltd | Construction | 2017 |
| Conquest Centre Limited | Other services | 2004 |
| Conservatory & Window Specialists Ltd | Construction | 2014 |
| Consortia Group Limited | Financial services | 2020 |
| Consortia Personnel Ltd | Administrative & support | 2010 |
| Construction Industry Accounting Ltd | Professional & scientific | 2020 |
| Construction Project Management Services Ltd | Construction | 2019 |
| Consultancy Management and Training Services Ltd. | Education | 2000 |
| Content by Brynna Limited | Wholesale & retail | 2025 |
| Content Craft Ltd | Information & communication | 2020 |
| Content Healthcare Network Limited | Information & communication | 2012 |
| Content Publishing Limited | Information & communication | 2011 |
| Contort Limited | Manufacturing | 2026 |
| Contract Energy Services Ltd | Professional & scientific | 2012 |
| Controlpcb Limited | Manufacturing | 2020 |
| Convections Limited | Construction | 2002 |
| Convert X Media Ltd | Professional & scientific | 2023 |
| Convinced Ltd | Administrative & support | 2025 |
| Cooke Financial Group Limited | Financial services | 2025 |
| Cooke Partnership Ltd | Agriculture & fishing | 2008 |
| Cooks Commercials Limited | Transport & logistics | 2003 |
| Coolwave Consulting Ltd | Professional & scientific | 2024 |
| Coombe Farm Court Management Company Limited | Households | 2022 |
| Coombe Farm Storage Solutions Limited | Real estate | 2008 |
| Coomber Security Systems Limited | Administrative & support | 1990 |
| Cooper & Phillips Brickwork & Building Ltd | Construction | 2020 |
| Cooper Associates Accountants Limited | Professional & scientific | 2016 |
| Cooper Associates Foundation | Administrative & support | 2018 |
| Cooper Associates Group Limited | Financial services | 2015 |
| Cooper Associates Holdings Limited | Financial services | 2018 |
| Cooper Associates Limited | Financial services | 2008 |
| Cooper Associates Wealth Management Limited | Financial services | 2009 |
| Cooper Holidays Ltd | Administrative & support | 2023 |
| Cooper Properties Limited | Real estate | 2013 |
| Corbel Conservation Ltd | Construction | 2002 |
| Corbel Joinery Ltd | Manufacturing | 2022 |
| Cordy Construction Limited | Construction | 2021 |
| Core Concept Marketing Ltd | Wholesale & retail | 2018 |
| Corner Club Taunton Ltd | Hospitality | 2021 |
| Corner Cottage Associates Limited | Professional & scientific | 2023 |
| Cornerstone 2023 Ltd | Real estate | 2023 |
| Cornhill Dental Limited | Health & social care | 2018 |
| Cornish Close Management Limited | Households | 2024 |
| Cornish Nurseries Limited | Health & social care | 2012 |
| Cornmill Facilities Management Company Limited | Real estate | 2009 |
| Cornucopia Life Limited | Health & social care | 2009 |
| Corona Studio Limited | Health & social care | 2018 |
| Coronation Way Management Company Limited | Households | 2024 |
| Corporate European Holdings PLC | | 1990 |
| Corps Properties Limited | Real estate | 2017 |
| Corrival Capital Management Limited | Administrative & support | 2019 |
| Corrosion & Water-Control UK Limited | Financial services | 2007 |
| Corton Holdings Ltd | Administrative & support | 2018 |
| Cosae Deniz Ltd | Hospitality | 2019 |
| Costello Occupational Therapy Limited | Health & social care | 2011 |
| Costello Property Ltd | Real estate | 2023 |
| Costgard Ltd | Information & communication | 1997 |
| Costons Greenford Limited | Households | 2026 |
| Cosy Barn Holidays Limited | Hospitality | 2020 |
| Cosy Stoves Limited | Construction | 2021 |
| COSY25 Ltd | Hospitality | 2025 |
| Cotford Property Services Ltd | Construction | 2025 |
| Cotleigh Brewery Limited | Manufacturing | 2003 |
| Cotleigh Farms (SW) Ltd | Agriculture & fishing | 2026 |
| Cotleigh Farms Limited | Agriculture & fishing | 2003 |
| Cotswold Heritage Developments Ltd | Real estate | 2024 |
| Cotswold Luxury Kitchens Ltd | Wholesale & retail | 2024 |
| Cottage Place (Management Company) Limited | Households | 2009 |
| Cotton Brands Ltd | Wholesale & retail | 2025 |
| Cotton Motors Limited | Wholesale & retail | 2019 |
| Cottonsoft Baby Ltd | Extraterritorial | 2008 |
| Cottonsoft Ltd | Extraterritorial | 2000 |
| Counselling Channel Ltd | Wholesale & retail | 2008 |
| Counselling Psychology Services Ltd | Financial services | 1996 |
| Country Cars & Vans Ltd | Wholesale & retail | 2013 |
| Country Fine Cuisine Ltd | Hospitality | 2018 |
| Country of Origin Ltd. | Manufacturing | 2016 |
| Country Property Search Limited | Real estate | 2018 |
| Country Rovers (Taunton) Ltd | Wholesale & retail | 2003 |