| Christal Supplies Ltd | Wholesale & retail | 2003 |
| Christian Broadcasting Corporation Limited | Information & communication | 1984 |
| Christopher Frederick Howe Ltd | Extraterritorial | 2025 |
| Chronic Pain Coaching CIC | Health & social care | 2023 |
| Chrysalid Limited | Real estate | 2019 |
| Chrzan Transport Ltd | Transport & logistics | 2018 |
| Chtechcoaching Ltd | Education | 2024 |
| Chubb Developments Ltd | Construction | 2010 |
| Chubb Electrics Ltd | Construction | 2008 |
| Chuk Medtech Innovations Ltd | Health & social care | 2024 |
| Chuley Road Garage Ltd | Wholesale & retail | 2021 |
| Church Road Plymouth Properties Limited | Real estate | 2015 |
| Churchill Electrical Limited | Construction | 1998 |
| Churchill Services Limited | Real estate | 1995 |
| Churchward Electrical Solutions Ltd | Construction | 2026 |
| Churchwood Forest School CIC | Agriculture & fishing | 2023 |
| Churchwood Valley Limited | Hospitality | 2011 |
| Churchyard Electrical Ltd | Construction | 2019 |
| CI Automotive Ltd | Wholesale & retail | 2022 |
| Ci-Sw Ltd | Other services | 2018 |
| Cibus Europe Limited | Administrative & support | 2011 |
| CIELO24 Limited | Health & social care | 2024 |
| Cikem Medical Services Limited | Health & social care | 2025 |
| Circular Surplus Ltd | Wholesale & retail | 2024 |
| Circular Textiles Foundation | Professional & scientific | 2021 |
| Citadel Court (Plymouth) RTM Company Limited | Households | 2025 |
| Citadel Electrical Services Limited | Construction | 2013 |
| Citadel Publishing Ltd | Information & communication | 2021 |
| Citarep Limited | Real estate | 1980 |
| City Barbers (SW) Ltd | Other services | 2024 |
| City Barbers Plymouth Ltd | Other services | 2019 |
| City Car Parks Limited | Transport & logistics | 2018 |
| City Car Wash Ltd | Administrative & support | 2018 |
| City Care Southwest Ltd | Health & social care | 2023 |
| City Centre Chiropody Ltd | Health & social care | 2024 |
| City Clinic South West Limited | Health & social care | 2022 |
| City Couriero Ltd | Transport & logistics | 2020 |
| City Furnishers Store Limited | Wholesale & retail | 2015 |
| City Furnishers Stores Plymouth Limited | Wholesale & retail | 2026 |
| City Gent Barbers Limited | Other services | 2019 |
| City of Plymouth Trampoline & Gymnastics CIC | Arts & recreation | 2022 |
| City Security Consultants Ltd | Administrative & support | 2023 |
| City Security Limited | Administrative & support | 2015 |
| City Security Solutions Ltd | Administrative & support | 2023 |
| City Security Training Limited | Administrative & support | 2020 |
| Citylease Limited | Real estate | 1999 |
| Citylets (Plymouth) Limited | Real estate | 2019 |
| Citysales (Plymouth) Ltd | Real estate | 2011 |
| Civil Engineering Services Company Limited | Professional & scientific | 1989 |
| CJ Estates Lettings Limited | Real estate | 2025 |
| CJ Holdings Plymouth Ltd | Financial services | 2025 |
| CJ Proplan Ltd | Financial services | 2014 |
| CJ Roofing SW Ltd | Construction | 2025 |
| CJC Electrical South West Limited | Construction | 2017 |
| CJM Install Ltd | Construction | 2018 |
| CJR Candles Limited | Manufacturing | 2025 |
| CJR Properties Ltd | Real estate | 2025 |
| CJS Groundworks Ltd | Construction | 2019 |
| CJS Services (Kent) Ltd | Construction | 2019 |
| Cjsm UK Ltd | Wholesale & retail | 2019 |
| Cjsp Consulting Ltd | Professional & scientific | 2025 |
| CK Inn (Cawsand) Ltd | Hospitality | 2025 |
| CK SOL Holdings Ltd | Financial services | 2023 |
| Ckcs Plymouth Ltd | Extraterritorial | 2021 |
| Ckcs South West Limited | Hospitality | 2021 |
| CKH Property Ltd | Real estate | 2025 |
| CKW Installations Ltd | Construction | 2019 |
| CL Matthews Properties Ltd | Real estate | 2023 |
| Claddeck Limited | Construction | 2023 |
| Cladding Supplies Online Ltd | Wholesale & retail | 2019 |
| Claimlock Ltd | Professional & scientific | 2025 |
| Claire Norwood Property Limited | Real estate | 2017 |
| Claire Stanton Limited | Health & social care | 2016 |
| Claire's Snacks Ltd | Hospitality | 2021 |
| Claires Candy Cart Ltd | Hospitality | 2025 |
| Clan Financial Services Limited | Financial services | 2008 |
| Claremont Marine Services Limited | Construction | 2023 |
| Clarendon House Property Management Limited | Households | 2007 |
| Clarham Court Limited | Real estate | 2000 |
| Clarity Car Sales (SW) Ltd | Wholesale & retail | 2026 |
| Clark House Dental Surgeries Limited | Health & social care | 2008 |
| Clarks Rigging & Lifting (NE) Ltd | Professional & scientific | 2019 |
| Class Barber (SW) Ltd | Other services | 2022 |
| Classclean Solutions Ltd | Administrative & support | 2025 |
| Classic 14 Holdings Limited | Professional & scientific | 2012 |
| Classic Builders (South West) Limited | Construction | 2003 |
| Classic Builders Trustees Limited | Professional & scientific | 2025 |
| Classic Grill House Ltd | Hospitality | 2022 |
| Classic Grill House Plymouth Ltd | Hospitality | 2025 |
| Classic Homes (South West) Limited | Real estate | 2013 |
| Classic Modern Retro Ltd | Administrative & support | 2022 |
| Classic Mouldings by LEE Vanstone Ltd | Construction | 2020 |
| Classic Plant Limited | Construction | 2013 |
| Classic Services (SW) Ltd | Wholesale & retail | 2022 |
| Classroom Table Company Limited | Extraterritorial | 2021 |
| Classyzone Limited | Wholesale & retail | 2025 |
| Claybrook Limited | Real estate | 2001 |
| Clean Canvas Solutions Limited | Administrative & support | 2025 |
| Clean Green Tech Limited | Professional & scientific | 2018 |
| Clean Group SW Ltd | Administrative & support | 2018 |