| Cmmh Limited | Construction | 2023 |
| CMS Property Lettings Ltd | Real estate | 2025 |
| Co-Teq Ltd | Real estate | 2026 |
| Coast House Limited | Professional & scientific | 2018 |
| Coastal Aesthetics & Skin Limited | Health & social care | 2025 |
| Coastal Civils & Construction Ltd | Construction | 2023 |
| Coastal Construction Management Limited | Construction | 2012 |
| Coastal Energy Kent Limited | Construction | 2015 |
| Coastal Mowers & Plant Limited | Other services | 2026 |
| Coastal Properties South East Limited | Real estate | 2025 |
| Coastal Rides Ltd | Manufacturing | 2008 |
| COD Bitters Ltd | Hospitality | 2024 |
| Codon Partners LLC | | 2025 |
| Coeval Fires Limited | Construction | 2011 |
| Coggers Management Company Limited | Households | 2016 |
| Cojala Limited | Information & communication | 2015 |
| Colin Brown Procurement Consultants Limited | Real estate | 2007 |
| Colin Caley Limited | Extraterritorial | 2024 |
| Colwell & Friend Haulage Limited | Transport & logistics | 2015 |
| Come a Casa Mediterranean Ltd | Hospitality | 2021 |
| Comercio Y Gestion Global LLP | | 2022 |
| Commcon Events Ltd | Administrative & support | 2018 |
| Commercial and Car Repairs Ltd | Professional & scientific | 2024 |
| Commercial Management Hub Ltd | Professional & scientific | 2025 |
| Compagnie Monegasque DE L Immobilier ET DE LA Finance Ltd | Extraterritorial | 2017 |
| Complete Fire Protection Upgrades Limited | Construction | 2021 |
| Complete Online Marketing Service Limited | Professional & scientific | 2016 |
| Concrete-Equipment Ltd | Professional & scientific | 2020 |
| Conrad Robinson Limited | Construction | 2014 |
| Construction Driani Ltd | Extraterritorial | 2017 |
| Container Centre Limited | Wholesale & retail | 2025 |
| Coombe Valley M.O.T Centre Ltd | Wholesale & retail | 2018 |
| Copper Maintenance Limited | Construction | 2024 |
| Cordova Court (Folkestone) Management Company Limited | Households | 1971 |
| Core Operational and Services Team Limited | Transport & logistics | 2018 |
| Corporation Yard Limited | Real estate | 2021 |
| Corrigans Engineering Ltd | Construction | 2019 |
| Corrupted ERA Ltd | Wholesale & retail | 2023 |
| Cortx AI Limited | Information & communication | 2023 |
| Cosbuild and Maintenance Ltd | Construction | 2021 |
| Costruzioni Roghi Ltd | Manufacturing | 2019 |
| Cotswold Country Pursuits Limited | Arts & recreation | 2016 |
| County Taxis (Dover) Limited | Transport & logistics | 2012 |
| Court Sports UK Ltd | Arts & recreation | 2025 |
| Cousins UK Barbers Ltd | Other services | 2026 |
| Covenant Wells Church CIC | Education | 2025 |
| CP Hospitality Ltd | Hospitality | 2025 |
| CPJ Associates Ltd | Administrative & support | 2017 |
| CRA95 Pizza and Fish Limited | Hospitality | 2025 |
| Crabble Corn Mill Trading Ltd | Wholesale & retail | 2005 |
| Crabble Heights (Dover) Limited | Professional & scientific | 2016 |
| Craig Wallis Landscapes Limited | Administrative & support | 2023 |
| Creedy Number 1 Limited | Health & social care | 2007 |
| Crewcorp Ltd | Professional & scientific | 2022 |
| CRF Installations Ltd | Construction | 2021 |
| Cronin Commercials Ltd | Wholesale & retail | 2025 |
| Crops Liase Ltd Limited | Agriculture & fishing | 2025 |
| Cross Grain Carpentry Ltd | Manufacturing | 2019 |
| Cross Tutoring Ltd | Education | 2026 |
| Cross-Links Dover | Professional & scientific | 2007 |
| Crossfield Craft Ltd | Manufacturing | 2012 |
| Crown Hill Properties Limited | Construction | 1999 |
| Crowns and Curls Ltd | Wholesale & retail | 2024 |
| CRP Carpentry Limited | Construction | 2026 |
| Crunch 'N' Munch Ltd | Hospitality | 2024 |
| CSB Investment Holdings Limited | Financial services | 2022 |
| Csit Services Ltd | Information & communication | 2008 |
| CSN Project Planning Limited | Construction | 2008 |
| CT Catering Kent Ltd | Hospitality | 2025 |
| CT Clearance Services Ltd | Transport & logistics | 2021 |
| CT Construction South East Limited | Construction | 2026 |
| Cudworth & Bates Ltd | Wholesale & retail | 2026 |
| Culver & Reichmann LLP | | 2010 |
| Curiosity of Dover Limited | Wholesale & retail | 2005 |
| Curvo Corporation | | 2024 |
| CUT Keys Direct Limited | Manufacturing | 2009 |
| CW Signalling Limited | Construction | 2016 |
| Cytoinnovations Ltd | Professional & scientific | 2013 |
| D Collip Limited | Real estate | 2018 |
| D K Photographer Limited | Professional & scientific | 2014 |
| D L & M Services Ltd | Construction | 2025 |
| D N Fletcher & Sons Limited | Construction | 2008 |
| D Nuttall UK Ltd | Transport & logistics | 2008 |
| D P Maxwell Plumbing & Heating Ltd | Construction | 2017 |
| D. Norris Tyres Ltd | Manufacturing | 2023 |
| D. P. Lead and Sons Ltd | Wholesale & retail | 2002 |
| D. R. G. Site Services Ltd | Professional & scientific | 2013 |
| D.U.L Laboratories Limited | Professional & scientific | 2015 |
| D.W.Ferguson Limited | Agriculture & fishing | 1944 |
| DAH Rail Services Limited | Construction | 2017 |
| Dairy Mews (Deal) Management Company Limited | Households | 2009 |
| Dalmas Property Limited | Construction | 2021 |
| Damaby Engineering Ltd | Professional & scientific | 2019 |
| Damp EX Kent Ltd | Construction | 2021 |
| Dane Court Residents Association Limited | Households | 1989 |
| Dani's Hair and Beauty Limited | Other services | 2018 |
| Daniel Burrows Design Ltd | Professional & scientific | 2017 |
| Daniel- Constable.Com Ltd | Other services | 2023 |
| Dapa Dance Ltd | Arts & recreation | 2003 |
| DAR AL Khair Property Ltd | Households | 2023 |