| Chesterton Consulting Limited | Professional & scientific | 2015 |
| Child Relief Limited | Other services | 2010 |
| Childrensclubs Ltd | Education | 2025 |
| Chip-In Sports Limited | Arts & recreation | 2025 |
| Chisholm & Sons Limited | Construction | 2014 |
| Chordoma UK | Health & social care | 2016 |
| Chreia Ltd | Real estate | 2024 |
| Chydane TSL Consulting Ltd | Professional & scientific | 2024 |
| Cindy Swim School LLP | | 2018 |
| Cindy's Swim School Ltd | Education | 2013 |
| Cini Fire Tech Ltd | Information & communication | 2011 |
| Cirrus Cost Control Ltd | Information & communication | 2025 |
| City Kids Ltd | Information & communication | 2014 |
| City Knowledge Ltd | Education | 2008 |
| Cityguard Gates Limited | Manufacturing | 2026 |
| Civic Connect Ltd | Administrative & support | 2026 |
| Civic Networks Limited | Administrative & support | 2011 |
| CJC Offshore Solutions Ltd | Professional & scientific | 2016 |
| Ckaps Ltd | Financial services | 2025 |
| Claimco Ltd | Information & communication | 2019 |
| Claire Evans Limited | Arts & recreation | 2012 |
| Claire Morrell Limited | Education | 2013 |
| Claremont Cars Limited | Transport & logistics | 2007 |
| Claremont FAN Court Enterprises Limited | Real estate | 1983 |
| Claremont FAN Court Foundation Limited(The) | Education | 1976 |
| Claremont Flooring Limited | Construction | 2010 |
| Clarkson Residential Ltd | Real estate | 2017 |
| Claygate Builders Ltd | Construction | 2019 |
| Claygate Designs Limited | Professional & scientific | 2023 |
| Claygate Energy Limited | Professional & scientific | 2010 |
| Claygate Management Services Limited | Professional & scientific | 2017 |
| Claygate Market Limited | Hospitality | 2024 |
| Claygate One Ltd | Real estate | 2025 |
| CLB Enterprises Limited | Hospitality | 2016 |
| Cleanopps Ltd | Real estate | 2016 |
| Clears Yard Developments Limited | Construction | 2022 |
| Clearvoice Comms Limited | Professional & scientific | 2016 |
| CLEMENTI12 Limited | Professional & scientific | 2012 |
| Cleveland Bay Limited | Financial services | 2016 |
| Click Supplies Limited | Construction | 2023 |
| Clickphone Communications Ltd | Information & communication | 2010 |
| Client Server Group Limited | Financial services | 2011 |
| Client Server Ltd | Administrative & support | 1999 |
| CLM Consulting Services Ltd | Professional & scientific | 2018 |
| CLOUDPC365 Limited | Manufacturing | 2013 |
| CLP Risk Management Limited | Professional & scientific | 2019 |
| CLS Accountants Limited | Professional & scientific | 2017 |
| Club 8 Barber Ltd | Other services | 2020 |
| Cmapr Limited | Real estate | 2023 |
| Cmdi Limited | Professional & scientific | 2020 |
| Cobbetts Hill Developments Limited | Real estate | 2020 |
| Cobham Didi Rugby Limited | Arts & recreation | 2019 |
| Cobham Park Veterinary Clinic Ltd | Professional & scientific | 2010 |
| Codebow Ltd | Information & communication | 2022 |
| Codecranks Ltd | Information & communication | 2025 |
| Coffee Dog Digital Ltd | Professional & scientific | 2014 |
| Coffee PUP Limited | Hospitality | 2025 |
| Cogl Properties Limited | Real estate | 2021 |
| Cognatic Limited | Professional & scientific | 2026 |
| Cohesion Education Group Limited | Administrative & support | 2026 |
| Coldunell Finance Limited | Financial services | 2016 |
| Coldunell Limited | Real estate | 1959 |
| Colin Frewin and Associates Ltd. | Administrative & support | 1996 |
| COLLIGO14 Ltd | Professional & scientific | 2019 |
| Combined Counties Properties Limited | Agriculture & fishing | 1978 |
| Commercial to Homes Ltd | Construction | 2024 |
| Community Unlimited Elmbridge Ltd | Professional & scientific | 2025 |
| Compass Engineering Services Ltd | Construction | 2018 |
| Concept Construction (Surrey) Limited | Construction | 2013 |
| Concise Auditing Limited | Professional & scientific | 2000 |
| Concordis Limited | Information & communication | 2018 |
| Connect Cars for Sale LLP | | 2024 |
| Conor Dufficy Ltd | Professional & scientific | 2023 |
| Conran Contracts Limited | Construction | 2011 |
| Constone Ltd | Professional & scientific | 2024 |
| CONTROL6SMARTHOMES Ltd | Construction | 2023 |
| Convene UK Limited | Information & communication | 2017 |
| Cooke Rowell Limited | Professional & scientific | 2005 |
| Coombe Property Development Limited | Real estate | 1962 |
| Copa Partners Limited | Professional & scientific | 2017 |
| Cornerstone Housing Partners Limited | Real estate | 2026 |
| Cosmo Plastics Limited | Real estate | 1965 |
| Couchmore Front Garden Limited | Professional & scientific | 2019 |
| Council for the Defence of British Universities | Education | 2012 |
| Countrywide Machinery Services Limited | Extraterritorial | 2014 |
| Cousins Fruiterers Limited | Wholesale & retail | 2026 |
| Cousins of Twickenham Limited | Wholesale & retail | 2015 |
| CR Scenery Ltd | Construction | 2025 |
| Crackley Ltd | Administrative & support | 2011 |
| Crane & Associates Limited | Professional & scientific | 1997 |
| Crane Energy Limited | Professional & scientific | 2012 |
| Creating IT Limited | Professional & scientific | 2002 |
| Creative Bears Ltd | Professional & scientific | 2022 |
| Creative Souls Events Ltd | Arts & recreation | 2024 |
| Crebris Ltd | Mining & quarrying | 2017 |
| Credit Partners Limited | Administrative & support | 2015 |
| Cremin Gridworks Limited | Construction | 2016 |
| Crom a BOO Advisory Services Limited | Professional & scientific | 2026 |
| Crom a BOO Limited | Other services | 2015 |
| Crom a BOO Properties Limited | Other services | 2020 |