| Commissioners Hayfield Residents Company Limited | Households | 2001 |
| Commonwealth Academy of Medical Sciences Ltd | Education | 2026 |
| Complete Property Network Limited | Real estate | 2003 |
| Complete Workspace Solutions Ltd | Wholesale & retail | 2016 |
| Computerwares Limited | Information & communication | 1995 |
| Concengeles Limited | Health & social care | 2020 |
| Concept Business Services Limited | Administrative & support | 2019 |
| Concept Corporate Management Limited | Administrative & support | 2008 |
| Concrete Visuals Ltd | Professional & scientific | 2014 |
| Congo Century Grand Truck Sales Limited | Wholesale & retail | 2024 |
| Coniston Accounting Ltd | Professional & scientific | 2023 |
| Conjoint Ltd | Hospitality | 2018 |
| Connect and Care Ltd | Health & social care | 2019 |
| Connect Personnel Limited | Administrative & support | 1999 |
| Connectech UK Ltd | Information & communication | 2018 |
| Connecttech Electrical Ltd | Construction | 2019 |
| Consilient Engineering Ltd | Professional & scientific | 2018 |
| Constant Comfort Ltd | Construction | 2019 |
| Construction Labour Personel Ltd | Construction | 2019 |
| Construction Logistics Management Limited | Professional & scientific | 2020 |
| Construction Logistics Planning Limited | Professional & scientific | 2015 |
| Content Factory International Ltd | Education | 2024 |
| Context One Archaeological Services Limited | Professional & scientific | 2006 |
| Continental Carpentry Ltd | Construction | 2023 |
| Conway Court Residents' Association Company Limited | Households | 2004 |
| Conway Hall Management Company Limited | Households | 1994 |
| Conwilmor Ltd | Wholesale & retail | 2025 |
| Cool Tech (South East) Limited | Manufacturing | 2017 |
| Coola Freight Ltd | Transport & logistics | 2019 |
| Cope Capital Ltd | Financial services | 2025 |
| Copeland-Odonkor Ministries Ltd | Information & communication | 2025 |
| Copperfield Building Services Limited | Construction | 1998 |
| Copperhouse Farm Management Limited | Real estate | 2007 |
| Coral Financial Planning LLP | | 2022 |
| Coram Construction Training Ltd | Administrative & support | 2017 |
| Cordial Consulting Ltd | Professional & scientific | 2018 |
| Core Acquest Properties Limited | Real estate | 2022 |
| Coreth Arts Limited | Arts & recreation | 2012 |
| Cormorant Apartments Freehold Limited | Households | 2017 |
| Cormorant Apartments RTM Limited | Households | 2006 |
| Cornerstone Homes South Ltd | Construction | 2024 |
| Cornerstone Property Associate Ltd | Real estate | 2020 |
| Corporate Security Solutions Limited | Administrative & support | 2011 |
| Cosek Homes Ltd | Real estate | 2022 |
| Cosmadelivery Ltd | Transport & logistics | 2018 |
| Cosmo Cosmetics Ltd | Manufacturing | 2019 |
| Costa Coffee Limited | Extraterritorial | 2005 |
| Countermeasure Consulting Ltd. | Financial services | 2012 |
| County Scaffolding Medway Limited | Wholesale & retail | 2003 |
| County Security Installations Limited | Administrative & support | 2011 |
| Coveney Consulting Limited | Professional & scientific | 2013 |
| Coward Projects Ltd | Construction | 2018 |
| Cowdray Construction Limited | Construction | 2022 |
| Cowdry Electrical Ltd | Construction | 2026 |
| Cozy Corp Limited | Wholesale & retail | 2014 |
| Cozy Trading Ltd | Wholesale & retail | 2022 |
| CR Real Estate Ltd | Real estate | 2022 |
| Crafty Fish Limited | Professional & scientific | 2017 |
| Craig Blundy Financial Services Ltd | Financial services | 2026 |
| Cranbri Web Solutions Ltd | Information & communication | 2013 |
| Crane House BR1 Ltd | Households | 2011 |
| Crane Mill Homes Limited | Construction | 2024 |
| Crave the Rave Ltd | Arts & recreation | 2024 |
| Credible Services Ltd | Transport & logistics | 2025 |
| Crescent Digital Services Limited | Information & communication | 2019 |
| Crestmoor Flood Defence Ltd | Extraterritorial | 2020 |
| Crestmoor Group Ltd | Financial services | 2020 |
| Crestmoor Training LLP | | 2015 |
| Crestwood Care Limited | Health & social care | 2025 |
| Crews Garage Limited | Wholesale & retail | 2002 |
| CRG Carpentry & Maintenance Ltd | Other services | 2023 |
| Crispr Ltd | Manufacturing | 2023 |
| Crockett Martial Arts Ltd | Arts & recreation | 2024 |
| Crocus Cafe Ltd | Hospitality | 2016 |
| Cromarty House RTM Company Ltd | Households | 2020 |
| Cronin & Millward Decorating Ltd | Construction | 2018 |
| Cronin Designs Ltd | Professional & scientific | 2022 |
| Cross Street Tyre Ltd | Wholesale & retail | 2023 |
| Crossfit Medway Ltd | Arts & recreation | 2021 |
| Crossted Properties Ltd | Real estate | 2023 |
| Crown Cargo Limited | Transport & logistics | 2021 |
| Crownend Limited | Transport & logistics | 2011 |
| CRW Services Ltd | Construction | 2026 |
| Crystal Accounting Limited | Professional & scientific | 2012 |
| Crystal Curtain & Blind Manufacturers Ltd | Manufacturing | 2002 |
| CS Training Academy Ltd | Real estate | 2025 |
| CSA Industries Ltd | Wholesale & retail | 2020 |
| CSI Management Ltd | Real estate | 2008 |
| CST Brother’S Ltd | Construction | 2026 |
| CT Fire Limited | Public administration | 2026 |
| CTA Technologies Ltd | Wholesale & retail | 2021 |
| CTM Exterior Cleaning Ltd | Administrative & support | 2026 |
| Ctrans Limited | Transport & logistics | 2014 |
| Cube Construction and Developments Ltd | Construction | 2025 |
| Cuge Limited | Construction | 2026 |
| Cullen Properties Ltd | Real estate | 2019 |
| Cullinan Cleans Ltd | Administrative & support | 2022 |
| Cultbaby Ltd | Wholesale & retail | 2023 |
| Custom Business Solutions UK Limited | Information & communication | 2004 |
| Custom Fit Tailoring & Alterations Ltd | Other services | 2015 |