| Colbyrne Construction Ltd | Construction | 2021 |
| COLD3R Ltd | Professional & scientific | 2011 |
| Coldblow Equestrian Centre Limited | Arts & recreation | 2016 |
| Coldharbour Property Management RTM Company Limited | Households | 2012 |
| Coleron Construction Ltd | Professional & scientific | 2023 |
| Colesdane Management Limited | Households | 2002 |
| Colette Hall Mortgage Finance Ltd | Financial services | 2018 |
| Colgate Investments Limited | Administrative & support | 2025 |
| Colin Access & Egress Consultancy Ltd | Professional & scientific | 2025 |
| Colin Farley & Associates Limited | Professional & scientific | 2006 |
| Collabaway Ltd | Information & communication | 2024 |
| Collagen for Dogs Ltd | Wholesale & retail | 2023 |
| Collaro Audio Ltd | Wholesale & retail | 2018 |
| Collclan Developments Ltd | Construction | 2014 |
| College Avenue (Maidstone) Company Limited | Households | 1998 |
| College Property Developments Limited | Construction | 2014 |
| Collie TM Ltd | Construction | 2023 |
| Colliers Wood Spice Ltd | Hospitality | 2016 |
| Collins Residential Support Ltd | Health & social care | 2025 |
| Colpez Ltd | Other services | 2026 |
| Colton Gardens Ltd | Other services | 2010 |
| Combat Promotion Ltd | Arts & recreation | 2015 |
| Combwell Wood Products Limited | Manufacturing | 2024 |
| Comet Consulting Limited | Information & communication | 2020 |
| Comm Centre Systems Ltd | Information & communication | 2008 |
| Commercial Ducting Ltd | Energy | 2016 |
| Commercial Play Ltd | Construction | 2020 |
| Commercial Venture Facilitators Limited | Financial services | 2017 |
| Common Sense Systems Limited | Information & communication | 2009 |
| Commonwealth Dancesport Limited | Education | 2025 |
| Comms Depot Limited | Information & communication | 2009 |
| Communitee Ltd | Manufacturing | 2015 |
| Community Digital Limited | Information & communication | 2015 |
| Community Resilience UK CIC | Public administration | 2006 |
| Comp Limited | Construction | 2023 |
| Company Attributes Ltd | Construction | 2019 |
| Company Design and Development Ltd. | Information & communication | 2017 |
| Compare and Recycle Limited | Extraterritorial | 2015 |
| Comparitech Limited | Information & communication | 2016 |
| Complete Advantage Limited | Financial services | 2013 |
| Complete Care Services Limited | Other services | 1995 |
| Complete Equine Hoofcare Ltd | Agriculture & fishing | 2012 |
| Complete Hygiene Kent Ltd | Administrative & support | 2024 |
| Complete Kitchen Services Limited | Construction | 2018 |
| Complete Wiring Solutions Limited | Construction | 2014 |
| Complete Your Own Circle Counselling Ltd | Health & social care | 2026 |
| Completely Free Publishing Limited | Information & communication | 2011 |
| Completely Kompact Drilling Ltd | Construction | 2019 |
| Composite Roofing & Building Company Ltd | Construction | 2014 |
| Compound Carpentry Ltd | Construction | 2018 |
| Compressor Maintenance Systems Limited | Manufacturing | 2012 |
| Compton Properties (Brighton) Limited | Real estate | 2019 |
| Compugen Solutions Limited | Information & communication | 2018 |
| Computer Contracting Limited | Information & communication | 2018 |
| Computex Recycling Ltd | Water & waste | 2025 |
| Comres Invest Limited | Real estate | 2025 |
| Concept Tide Ltd | Information & communication | 2025 |
| Conduct Electrical Services Ltd | Energy | 2010 |
| Cone 3 Limited | Financial services | 2021 |
| Cone GUY Limited | Transport & logistics | 2014 |
| Cone Ridge Limited | Hospitality | 2017 |
| Conelec Ltd | Construction | 2025 |
| Connect Asset Investments Ltd | Real estate | 2025 |
| Connect EMS Limited | Manufacturing | 2021 |
| Connect Risk Solutions Limited | Financial services | 2024 |
| Connections H.R. Limited | Information & communication | 2001 |
| Connolly Property Investments Limited | Real estate | 2016 |
| Conqueror Global Inc Ltd. | Construction | 2015 |
| Conquest Litho Limited | Manufacturing | 1980 |
| Conran Design Group Limited | Administrative & support | 1971 |
| Conrod Racing Ltd | Arts & recreation | 2016 |
| Consec Systems Ltd | Administrative & support | 2023 |
| Conservative Friends of Tamils Limited | Other services | 2021 |
| Considine (Canterbury) Limited | Professional & scientific | 2022 |
| Considine Holdings Limited | Financial services | 2020 |
| Consilium Town Planning Services Ltd | Professional & scientific | 2014 |
| Consort Events Management Ltd | Hospitality | 2025 |
| Consort SE Limited | Administrative & support | 1997 |
| Construction Aptitude Limited | Information & communication | 2017 |
| Construction Governance Group Limited | Financial services | 2022 |
| Construction Logistics Academy Ltd | Education | 2019 |
| Construction Plant & Resources Limited | Administrative & support | 2024 |
| Construction Talent Centre Ltd | Professional & scientific | 2025 |
| Construction Tax Services Limited | Professional & scientific | 2005 |
| Consult Group Capital Ltd | Financial services | 2020 |
| Consult Group Worldwide Limited | Financial services | 2015 |
| Consult MAX Limited | Professional & scientific | 2018 |
| Consulting and Coaching Ltd | Professional & scientific | 2022 |
| Consulting ST Ltd | Professional & scientific | 2017 |
| Consultoría Group Ltd | Administrative & support | 2025 |
| Contemporary Landscapes Limited | Other services | 2007 |
| Content Media Services Limited | Information & communication | 1990 |
| Contenthq Ltd | Information & communication | 2020 |
| Continuity of Care Services Limited | Health & social care | 2015 |
| Continuity Training Academy Limited | Education | 2020 |
| Contracked Lands Ltd | Agriculture & fishing | 2010 |
| Contract 4 Leasing Ltd | Administrative & support | 2019 |
| Contracts Engineering Limited | Manufacturing | 1998 |
| Control Apps Limited | Professional & scientific | 2011 |
| Contrust Limited | Administrative & support | 2022 |