| Courtwell Developments Limited | Real estate | 2004 |
| Courtwood Drive Limited | Real estate | 1971 |
| Couscon Limited | Financial services | 2000 |
| Cousins Construction Limited | Extraterritorial | 2006 |
| Cove Security Systems Limited | Administrative & support | 1996 |
| Covenant Ministries Worldwide Outreach (Cmwo) | Other services | 2008 |
| Coverlift Limited | Wholesale & retail | 1987 |
| Covetree Estates Limited | | 1988 |
| CP Tech Europe Holding Ltd. | Financial services | 1997 |
| CPG Consult Limited | Professional & scientific | 2022 |
| Cpsq Limited | Information & communication | 2006 |
| Crabtree Projects Limited | Construction | 1999 |
| Craker Asphalt Limited | Construction | 2007 |
| Crane & Partners Limited | Professional & scientific | 2024 |
| Cranleigh Gardens (Whitstable) Management Company Limited | Households | 1979 |
| Cray Valley Properties Limited | Real estate | 2006 |
| Cray Valley Services | | 1990 |
| Crayford Press Limited | Manufacturing | 1974 |
| Crdm Trading Ltd | Wholesale & retail | 2024 |
| Cream Services London Ltd | Professional & scientific | 2005 |
| Create Plumbing and Heating Ltd | Construction | 2018 |
| Creative + Partners Ltd. | Hospitality | 2016 |
| Creative Ambition Limited | Professional & scientific | 2004 |
| Creative Authors Limited | Information & communication | 2008 |
| Creative Satellite Limited | Wholesale & retail | 2003 |
| Creative Visual Communications Limited | Professional & scientific | 2000 |
| Crebbin (Walton) Limited, | Real estate | 1963 |
| Creek Side Developments (Kent) Limited | Construction | 2004 |
| Cremorials Limited | Wholesale & retail | 2014 |
| Crescent Environmental Analysis Ltd | Professional & scientific | 2006 |
| Crestfield Technology Limited | Information & communication | 2000 |
| Crestlane Services Limited | Information & communication | 2000 |
| Cretebio Limited | Hospitality | 2013 |
| Crickmere Marketing Limited | Wholesale & retail | 1999 |
| Critical HIT Collectables Ltd | Other services | 2025 |
| Critical Mission Computing Ltd | Information & communication | 1999 |
| Critical Project Resourcing Limited | Administrative & support | 2004 |
| Crittenden (Pond Cottage) Limited | Wholesale & retail | 1964 |
| Crittenden (Warren Park) Limited | Hospitality | 1964 |
| Croftbond Limited | Real estate | 2005 |
| Crofton Design Services Limited | Professional & scientific | 2005 |
| Cromwell Security Services Limited | | 1986 |
| Crosskeys Coaches Limited | Transport & logistics | 2002 |
| Crosskeys UK Limited | Extraterritorial | 2006 |
| Crossways Management Company Limited | Real estate | 1988 |
| Crown Oceanic Limited | Information & communication | 2012 |
| Crown Sacks and Systems ( Aintree) Ltd | Manufacturing | 1953 |
| Crown Upholstery & Furnishing (Kent) Limited | Other services | 1985 |
| Crowncrest Trading Ltd | Wholesale & retail | 2025 |
| Croydon MOT Centre Limited | Wholesale & retail | 2004 |
| Croydon Technical Services Ltd. | Information & communication | 1993 |
| Cruise Club International Limited | Administrative & support | 1988 |
| Cruises 4 U Limited | Administrative & support | 2005 |
| Crustie's Limited | Hospitality | 1992 |
| Cryoquip Limited | Manufacturing | 1997 |
| Cryptorail Limited | Administrative & support | 2017 |
| Crystal Clear (UK) Limited | Wholesale & retail | 1994 |
| Crystal Fountains Ltd | Information & communication | 2000 |
| Crystal Water Co | | 1990 |
| CS Marine Consultants Limited | Real estate | 2007 |
| CS Venue & Events Limited | Hospitality | 2007 |
| CSN Motor Cycle Training Limited | Education | 2003 |
| CSS Lebanese Ltd | Hospitality | 2019 |
| CTM Medical Ltd | Health & social care | 2012 |
| Cube Custom Designs Limited | Professional & scientific | 2009 |
| Cube Design Consultants Limited | Information & communication | 2006 |
| Cuell Engineering Ltd | Professional & scientific | 2010 |
| Culverden TW Ltd | Real estate | 2018 |
| Culverhouse & Co. Ltd | Professional & scientific | 2007 |
| Curran Healthcare Ltd | Other services | 2009 |
| Curry Platform Ltd | Hospitality | 2020 |
| Cuthbert Consulting Limited | Professional & scientific | 2005 |
| Cutology Limited | Other services | 2004 |
| Cuxton Auto Services Ltd | Wholesale & retail | 2002 |
| CVK Ductwork Services Limited | Manufacturing | 2001 |
| CVK Engineering Limited | Manufacturing | 1998 |
| CW Unity PCN Limited | Health & social care | 2021 |
| Cypress Court Residents Association Limited | Households | 1992 |
| D & C Gray Civil Engineering Limited | Construction | 1997 |
| D & J Property Ltd | Real estate | 2024 |
| D & L London Limited | Wholesale & retail | 2005 |
| D & W Services Limited | Other services | 1996 |
| D and D Property Company Limited | Real estate | 2000 |
| D COX Carpentry Limited | Construction | 2006 |
| D E M Studio Limited | Real estate | 1998 |
| D Evans Rail/Civils Ltd | Other services | 2016 |
| D J S Ltd | Arts & recreation | 2005 |
| D K Networks Ltd | Other services | 2005 |
| D Morgan Welding Limited | Administrative & support | 1996 |
| D. Hines Transport Ltd | Transport & logistics | 2006 |
| D. Nebbs Building Contractors Ltd. | Construction | 2002 |
| D. R. P. Roofing Limited | Construction | 1979 |
| D. S. Brierly Limited | Wholesale & retail | 2002 |
| D.& M.Gedney Limited | Agriculture & fishing | 1962 |
| D.J. & G.S. Gardner Limited | Construction | 2002 |
| D.J.L. (Insurance Brokers) Limited | | 1960 |
| D.Obbard & Sons Limited | Agriculture & fishing | 1954 |
| D.P.Press Limited | Arts & recreation | 1956 |
| D.Sands Building Services (Kent) Ltd | Construction | 2004 |
| D2KTIME Ltd | Administrative & support | 2007 |