| Cbtreach Ltd | Education | 2020 |
| CEC Property Limited | Real estate | 2019 |
| Cedar Apartments Management Company Limited | Households | 2022 |
| Celsus Regulatory and Consulting Ltd | Professional & scientific | 2016 |
| Cemco Services Limited | Manufacturing | 1984 |
| Centre for Partnering Group Limited | Extraterritorial | 2019 |
| Centre for Partnering Limited | Public administration | 2018 |
| Cezarblue Ltd | Wholesale & retail | 2017 |
| Chalemoss Limited | Construction | 1998 |
| Chalk Down Research Limited | Professional & scientific | 2019 |
| Chalk Projects Ltd. | Professional & scientific | 1997 |
| Chapel Investments Ltd | Financial services | 2019 |
| Charlie Davis Studio Ltd | Arts & recreation | 2020 |
| Charlotte Day Property Services Ltd | Real estate | 2022 |
| Charlotte Gray Limited | Information & communication | 2000 |
| Charlotte Haigh Design Ltd | Professional & scientific | 2020 |
| Charnell Construction Limited | Construction | 2018 |
| Chasejones Holdings Ltd | Financial services | 2022 |
| Chasejones Property Holdings Ltd | Real estate | 2026 |
| CHC Enterprises Ltd | Extraterritorial | 2012 |
| Cherrett Consultancy Ltd | Information & communication | 2019 |
| Chester Lane Limited | Real estate | 1997 |
| Childcare Blueprint Ltd | Professional & scientific | 2026 |
| Chimera Lighting Limited | Information & communication | 2007 |
| Chinwags Ltd | Hospitality | 2023 |
| Chirpy Stories Limited | Information & communication | 2017 |
| Chocolateraisinfury Ltd | Arts & recreation | 2020 |
| Chris and Jane Limited | Manufacturing | 2010 |
| Christie Jameson Property Limited | Real estate | 2015 |
| Churcher's College | Education | 2017 |
| Churcher's College Enterprises Limited | Arts & recreation | 2006 |
| Circuit Engineering Marketing Company Limited | Manufacturing | 1980 |
| Circuit Engineering(N.D.R.)Limited | Professional & scientific | 1971 |
| Circuithub Limited | Information & communication | 2017 |
| City & Country Accounting Limited | Professional & scientific | 2014 |
| CJ Beauty and Consultant Ltd | Other services | 2026 |
| CJP Lemon Grove Holdings Ltd | Financial services | 2026 |
| CJP Property Developers Ltd | Construction | 2022 |
| Clantol Investments Limited | Real estate | 2020 |
| Classic Car Storage Limited | Transport & logistics | 1998 |
| Claypit Farm Barns Management Company Limited | Households | 2006 |
| Clear Solutions 03 Limited | Professional & scientific | 2003 |
| Clearmint Solutions Ltd | Information & communication | 2018 |
| Cleife Consulting Ltd | Information & communication | 2020 |
| Clickvision Media Ltd | Professional & scientific | 2010 |
| Cliquish 22 Limited | Administrative & support | 2016 |
| Clive Waller Consulting Limited | Professional & scientific | 2009 |
| Clobr Limited | Wholesale & retail | 2022 |
| Clubinmypocket Limited | Information & communication | 2020 |
| Cluson Engineering Limited | Manufacturing | 1975 |
| CO2CO Ltd | Professional & scientific | 2021 |
| Coach Kerr Ltd | Professional & scientific | 2021 |
| Coaching With ZOE Limited | Health & social care | 2021 |
| Coates & Grute Optometrists Limited | Wholesale & retail | 2022 |
| Cobblepath Games Ltd | Manufacturing | 2019 |
| Cockburn Ocean and Energy Ltd | Professional & scientific | 2024 |
| Coco, Hals and Friends Ltd | Wholesale & retail | 2025 |
| Coeus Technology Limited | Information & communication | 2010 |
| Cold AI Limited | Professional & scientific | 2025 |
| Collected Home Ltd | Wholesale & retail | 2019 |
| Colpepper Consultancy Limited | Administrative & support | 2026 |
| Colt Group Limited | Financial services | 1967 |
| Colt International Holdings Limited | Financial services | 1985 |
| Colt International Limited | Manufacturing | 1975 |
| Commodity Appointments Ltd | Extraterritorial | 2005 |
| Commonground Developments Limited | Real estate | 2021 |
| Compact Machinery Services Limited | Wholesale & retail | 2016 |
| Compass Consulting Services Limited | Professional & scientific | 2017 |
| Complete Health & Safety Solutions Limited | Professional & scientific | 2010 |
| Comus Limited | Information & communication | 2018 |
| Connections 1 Limited | Administrative & support | 2006 |
| Connections 2 Ltd | Education | 2025 |
| Consulting Ability Limited | Professional & scientific | 2004 |
| Contego Safety Solutions Ltd | Wholesale & retail | 2014 |
| Contract Investments Limited | Real estate | 2009 |
| Conundrum AI Process Control Ltd | Information & communication | 2024 |
| Conversations at the Edge Limited | Professional & scientific | 2020 |
| Cook Brewster Smith Limited | Arts & recreation | 1997 |
| Cooke’S Climate Solutions Ltd | Construction | 2025 |
| Cool Cargo Services Ltd | Other services | 2020 |
| Coombes Arboriculture Limited | Extraterritorial | 2018 |
| Coombes Civils Limited | Extraterritorial | 2017 |
| Coombes Environmental Limited | Construction | 2022 |
| Coombes Forestry Limited | Agriculture & fishing | 2009 |
| Coombes Frimstone Limited | Agriculture & fishing | 2023 |
| Coombes Group Limited | Financial services | 2022 |
| Coombes Holdings Limited | Construction | 2018 |
| Coombes Plant Limited | Construction | 2020 |
| Coombes Track Limited | Real estate | 2022 |
| Coram Pharma Limited | Professional & scientific | 2021 |
| Cork Investments Limited | Professional & scientific | 1999 |
| Cork Properties Limited | Professional & scientific | 2001 |
| Cornhill Business Advisors Ltd | Professional & scientific | 2011 |
| Cornwood House Management Company Limited | Professional & scientific | 1976 |
| Cosmopolitan House Ltd | Real estate | 2022 |
| Cossington House Management Company Limited | Professional & scientific | 1974 |
| Cotn Group Limited | Professional & scientific | 2025 |
| Cotton Consulting Services Ltd | Information & communication | 2026 |
| Coulston Consulting Limited | Professional & scientific | 2021 |
| Countryside Logs (GF) Ltd | Agriculture & fishing | 2022 |