| Cobra 1 Ltd | Administrative & support | 2025 |
| Cocker Doodle POO Limited | Agriculture & fishing | 2021 |
| Cocotec Limited | Information & communication | 2016 |
| Codecreative Studio Limited | Professional & scientific | 2009 |
| Codemasters Development Company Limited | Information & communication | 2015 |
| Codemasters Software Company Limited(The) | Information & communication | 1986 |
| Codeteam Limited | Information & communication | 2014 |
| Codex Games Limited | Information & communication | 2020 |
| Coelodonta Consulting Limited | Professional & scientific | 2022 |
| Coffee Point Limited | Wholesale & retail | 2019 |
| Cogitant Limited | Information & communication | 2008 |
| Cognitis Limited | Professional & scientific | 2004 |
| Cognosco Limited | Professional & scientific | 2001 |
| Cognosco Marketing Limited | Hospitality | 2005 |
| Cogs AI Ltd | Information & communication | 2021 |
| Colaj Consultancy Ltd | Professional & scientific | 2019 |
| Coldpiece Limited | Financial services | 2018 |
| Coldpiece Two Ltd | Financial services | 2021 |
| Colin Noon Associates Limited | Professional & scientific | 2005 |
| Collards Carpentry Limited | Manufacturing | 2024 |
| Collectible Couture Ltd | Wholesale & retail | 2012 |
| Collectors Tuck Shop Ltd | Wholesale & retail | 2024 |
| College of Contract Management Coaching and Consulting Ltd | Construction | 2011 |
| College of Contract Management United Kingdom Ltd | Education | 2013 |
| Collineige Limited | Administrative & support | 1980 |
| Collins Debden Limited | Manufacturing | 1986 |
| Collsport Consulting Ltd | Professional & scientific | 2015 |
| Coln Valley Smokery Limited | Manufacturing | 1974 |
| Coloma House Limited | Real estate | 2015 |
| Colonel & Co Limited | Professional & scientific | 2014 |
| Colorful London Limited | Wholesale & retail | 2020 |
| Columbia Road Restaurant LLP | | 2010 |
| COM Enterprises Ltd | Real estate | 2022 |
| Combloux Consulting Limited | Professional & scientific | 2022 |
| Comedy Wildlife Photography Awards Limited | Information & communication | 2015 |
| Comfort Aquatics Limited | Education | 2020 |
| Comfort International Limited | Construction | 1998 |
| Comit Projects Ltd | Construction | 2010 |
| Commercial and Industrial Properties Limited | Construction | 1980 |
| Commpilot Services Ltd | Transport & logistics | 2016 |
| Comms Unwired Ltd | Information & communication | 2023 |
| Communere Limited | Information & communication | 2011 |
| Community Sponsors Charity | Administrative & support | 2006 |
| Company 500 Limited | Construction | 2010 |
| Compass Consultants Limited | Information & communication | 1997 |
| Compass Energies Limited | Professional & scientific | 2023 |
| Compass Management Solutions Limited | Professional & scientific | 2023 |
| Complete Builds Surrey Ltd | Construction | 2025 |
| Complete Care Clinic Limited | Health & social care | 2004 |
| Complete Development Solutions Limited | Mining & quarrying | 2003 |
| Complete Footcare Clinic Ltd | Health & social care | 2011 |
| Complete Site Construct Ltd | Construction | 2015 |
| Completely EOT Limited | Extraterritorial | 2024 |
| Completely Over the Top Limited | Financial services | 2017 |
| Completely Property Technology Limited | Professional & scientific | 2012 |
| Compton Heights (Management) Limited | Households | 1995 |
| Computational Intelligence Ltd | Information & communication | 2025 |
| Computer Repairs Surrey Limited | Information & communication | 2014 |
| Comteam Limited | Professional & scientific | 2009 |
| Concept Fashion Agency Limited | Wholesale & retail | 2005 |
| Condor Systems Ltd | Manufacturing | 2025 |
| Congruent Business Services Group Ltd | Wholesale & retail | 2022 |
| Conidia Bioscience Limited | Manufacturing | 2000 |
| Conigliera Property Ltd. | Real estate | 2018 |
| Conisius Limited | Information & communication | 2024 |
| Conissaunce Limited | Information & communication | 2003 |
| Conkat Properties Limited | Real estate | 2019 |
| Conker PJ Limited | Wholesale & retail | 2018 |
| Connect Advisory Solutions Limited | Professional & scientific | 2021 |
| Connect Relocations & Storage Ltd | Transport & logistics | 2025 |
| CONNECT2MOBILE Limited | Wholesale & retail | 2011 |
| Connected Care Bidco Limited | Extraterritorial | 2022 |
| Connected Care Holdings Limited | Extraterritorial | 2022 |
| Connectid 1 Limited | Energy | 2023 |
| Connectid 2 Limited | Energy | 2023 |
| Connectid 3 Limited | Energy | 2023 |
| Connectid 9 Limited | Energy | 2023 |
| Connectopia Ltd | Professional & scientific | 2023 |
| Connectsurrey Ltd | Administrative & support | 2015 |
| Consay Limited | Professional & scientific | 2025 |
| Conscious Brands Limited | Wholesale & retail | 2024 |
| Consilium Recruit Ltd | Administrative & support | 2025 |
| Consortio Projects Ltd | Construction | 2024 |
| Consortium Hotels Ltd | Hospitality | 2026 |
| Consortium Sea Company Limited | Transport & logistics | 1983 |
| Constant Structural Design Limited | Construction | 2011 |
| Construct Electric Limited | Construction | 1995 |
| Construction IT Company Ltd | Other services | 2010 |
| Consult&Procure Ltd | Information & communication | 2015 |
| Consultancy Growth Network Ltd | Other services | 2019 |
| Consultium-Consultius Ltd | Professional & scientific | 2025 |
| Contactaspray Limited | Wholesale & retail | 2014 |
| Contour Construction & Interiors Limited | Construction | 2013 |
| Contour Construction Group Limited | Financial services | 2025 |
| Contour Electrical Limited | Construction | 2013 |
| Contour Electronics Limited | Manufacturing | 1992 |
| Contour Holdings Limited | Professional & scientific | 2009 |
| Contrail Consulting Limited | Professional & scientific | 2018 |
| Cooke Property Holdings Limited | Real estate | 2024 |
| Cookson Consultancy Limited | Professional & scientific | 2015 |