| Compass Music C.I.C. | Administrative & support | 2025 |
| Concepts Discretionary Investments Limited | Administrative & support | 2018 |
| Conchitas Restaurant Limited | Hospitality | 2012 |
| Condico Plumbing Services Ltd. | Construction | 2012 |
| Confidance Limited | Arts & recreation | 2020 |
| Confidence IT Limited | Information & communication | 2003 |
| Confident Minds Academy Limited | Education | 2026 |
| Connaught RD Management Ltd | Households | 2017 |
| CONNECT52 Ltd | Professional & scientific | 2025 |
| Connectionsuk CIC | Administrative & support | 2019 |
| Conservative Friends of Education Limited | Other services | 2019 |
| Conservative Political Action Conference UK (Britpac) Ltd | Administrative & support | 2020 |
| Consolidare Wealth Management Limited | Professional & scientific | 2018 |
| Constancia Court (Folkestone) Limited | Households | 2007 |
| Construct Studio Ltd | Professional & scientific | 2023 |
| Construction Fire Coatings Ltd | Construction | 2023 |
| Contador Lopez Limited | Extraterritorial | 2024 |
| Container-Ball Storage Solutions Limited | Transport & logistics | 2019 |
| Contract Harmony Ltd | Other services | 2011 |
| Contrast (South East) Properties Limited | Real estate | 2021 |
| CONTROL101 Limited | Manufacturing | 2021 |
| Convex Maintenance Ltd | Professional & scientific | 2025 |
| Cook Fabrications Limited | Manufacturing | 1983 |
| Cookstable Catering Limited | Hospitality | 2019 |
| Cooper PUP & Co. Ltd | Other services | 2025 |
| Cooper's Canine Services Ltd | Other services | 2023 |
| Coplant Limited | Administrative & support | 2007 |
| Copperline Plumbing Limited | Construction | 2021 |
| Coralridge Limited | Construction | 1987 |
| Core Sport Ltd | Wholesale & retail | 2016 |
| Core Therapies Clinics Limited | Administrative & support | 2019 |
| Cornfield Close Management Ltd | Extraterritorial | 2019 |
| Corniche Enterprises (Property) Limited | Administrative & support | 2022 |
| Correct Technology Limited | Information & communication | 2026 |
| Corvine Consulting Ltd | Professional & scientific | 2018 |
| Cossington Road Ltd | Real estate | 2021 |
| Cosy Cottage Romance Ltd | Wholesale & retail | 2026 |
| Cote DE Folk Ltd | Professional & scientific | 2021 |
| County Cobbler Ltd | Wholesale & retail | 2013 |
| County Windows (Kent) Limited | Construction | 2023 |
| Court Enforcement Direct Ltd | Administrative & support | 2016 |
| Cousins & Co Solicitors Ltd | Professional & scientific | 2021 |
| Cowgirl Restaurants Ltd | Administrative & support | 2024 |
| Craft Coffee Limited | Hospitality | 2013 |
| Craft Work Beverages Limited | Hospitality | 2024 |
| Crafted by Cat Ltd | Manufacturing | 2024 |
| Craftwork Master Thatchers Ltd | Construction | 2020 |
| Craig & Parsons Limited | Manufacturing | 1945 |
| Craig Gordon Limited | Real estate | 2019 |
| Cramer Court RTM Company Limited | Households | 2025 |
| Cranstone Asset Auctions Limited | Wholesale & retail | 2025 |
| Create Alchemy Limited | Professional & scientific | 2019 |
| Creatif Impressions Ltd | Administrative & support | 2001 |
| Creating Your Prosperity Ltd | Real estate | 2019 |
| Creative Community Limited | Arts & recreation | 2017 |
| Creative Construction and Landscapes Ltd | Administrative & support | 2023 |
| Creative Folkestone | Real estate | 2002 |
| Credit Denia Revolution Ltd | Financial services | 2021 |
| Credo Planning Limited | Other services | 2014 |
| Cressee House Limited | Households | 1998 |
| Crettprop Ltd | Real estate | 2023 |
| Criptic Productions CIC | Manufacturing | 2016 |
| Crisis Cleanup Ltd | Water & waste | 2024 |
| Cromwell Sandgate Management Company Limited | Households | 2010 |
| Cross Channel Consulting Limited | Transport & logistics | 2004 |
| Cross Channel Handling Transport and Storage Limited | Transport & logistics | 2017 |
| Crossferry Limited | Information & communication | 2021 |
| Crosskeys Travel Limited | Extraterritorial | 2015 |
| Crossroads Accounting Ltd | Professional & scientific | 2022 |
| Crownfield Homes Limited | Real estate | 2013 |
| Crownfield Leisure Limited | Real estate | 2020 |
| Crsi Security Services Ltd | Administrative & support | 2018 |
| Crusade Steel Ltd | Construction | 2026 |
| CT Autos Tyres and Servicing Limited | Wholesale & retail | 2023 |
| CT Twenty Ltd | Households | 2025 |
| CT20 Projects C.I.C. | Information & communication | 2017 |
| Ctec Solutions Ltd | Information & communication | 2013 |
| Cube Metal Recycling Ltd | Water & waste | 2010 |
| Cube Moving and Storage Limited | Transport & logistics | 2007 |
| Cube Restoration Limited | Water & waste | 2016 |
| CUQ International Limited | Information & communication | 2016 |
| Cura Aesthetics Limited | Health & social care | 2023 |
| Curae Group Ltd | Financial services | 2024 |
| Curzon Court Freehold Company Ltd | Households | 2021 |
| CVY Consulting Ltd | Information & communication | 2017 |
| Cyan Controls Ltd | Construction | 2017 |
| Cybersaur Arts Ltd | Education | 2021 |
| Cyquin Ltd | Information & communication | 2026 |
| D & H Barbers Ltd | Other services | 2025 |
| D and G Cars Ltd | Transport & logistics | 2023 |
| D Hooton Engineering Ltd | Professional & scientific | 2023 |
| D J Building Services (South East) Ltd | Construction | 2011 |
| D&C Business Services Ltd. | Professional & scientific | 2001 |
| D&G Transport Services Ltd | Transport & logistics | 2020 |
| D&M Real Estate Partners Ltd | Households | 2025 |
| D.A.T.S Services Ltd | Professional & scientific | 2020 |
| D.J. Gardiner Roofing & Building Limited | Construction | 2009 |
| D.J.B Furniture Emporium Ltd | Wholesale & retail | 2014 |
| Dadominoe Limited | Information & communication | 2018 |
| Dafi Building Store Ltd | Manufacturing | 2020 |