| Cromwells Estate Agents Ltd | Real estate | 2006 |
| Crondall Energy Consultants Ltd | Mining & quarrying | 2000 |
| Croslaw Limited | | 1892 |
| Crossing Jordan Limited | Administrative & support | 2004 |
| Crouch MGR Limited | Construction | 2007 |
| Croudace (Church Langley) Limited | Construction | 1994 |
| Croudace Homes Limited | Construction | 1964 |
| Crowley Accountancy Limited | Professional & scientific | 1998 |
| Crown Garages Kingston(Uk) Ltd | Wholesale & retail | 2019 |
| Crown Hall Estates Limited | Real estate | 1984 |
| Crowncare Limited | Health & social care | 2019 |
| Crowntask Limited | Real estate | 1993 |
| Croydon & Purley Acupuncture Practice Ltd | Other services | 2005 |
| Croydon Accessible Transport | Transport & logistics | 1999 |
| Croydon Business Centre Limited | Real estate | 1985 |
| Croydon Cleaning Supplies Limited | Administrative & support | 1994 |
| Croydon CP Trading Limited | Wholesale & retail | 1998 |
| Croydon Fruiterers Limited | Wholesale & retail | 2003 |
| Croydon GAS Sports Club Limited | Arts & recreation | 1996 |
| Croydon Judo Club Limited | Arts & recreation | 2005 |
| Croydon Metropolitan College Limited | Education | 2006 |
| Croydon Natural History and Scientific Society Limited | Information & communication | 1967 |
| Croydon Tabernacle | Extraterritorial | 1998 |
| Crystal Clear Cleaning & Maintenance Ltd | Administrative & support | 2004 |
| Crystal Peak Real Estate Ltd | Real estate | 2024 |
| CSS Car Sales Limited | Professional & scientific | 2003 |
| CTM Golden Enterprises Limited | Professional & scientific | 1995 |
| Cuddington (Banstead) Golf Club Limited | Arts & recreation | 1927 |
| Cuffe Harrell and Associates Limited | Mining & quarrying | 1994 |
| Culliford Buckingham | | 1993 |
| Culross Aerospace Limited | Professional & scientific | 2005 |
| Cultural Exhibitions Limited | Wholesale & retail | 1958 |
| Cunniffe Partnership | | 2001 |
| Cupinco Limited | Information & communication | 2001 |
| Cuppage Communications Limited | Professional & scientific | 2005 |
| Cure Pharmacy Ltd | Health & social care | 2014 |
| Curo Rosyth Limited Partnership | | 2007 |
| Current Accounts Limited | Professional & scientific | 2002 |
| Curtain LAB Ltd | Wholesale & retail | 2007 |
| Curtaincraft Limited | Manufacturing | 2005 |
| Curtis James Properties Limited | Real estate | 2021 |
| Custom Broadcasting Limited | Professional & scientific | 1988 |
| Custom Cable Service Limited | Wholesale & retail | 1997 |
| Customised Software Development (C.S.D.) Limited | | 1986 |
| Cute Business Limited | Construction | 1989 |
| Cutting Right UK Ltd | Other services | 2021 |
| Cybogen Limited | Information & communication | 1996 |
| CYM Mobile Ltd | Information & communication | 2002 |
| Czechoslovak National House Limited | Hospitality | 1941 |
| D & J Brook Consultants Limited | Information & communication | 2006 |
| D and Buildings Ltd | Construction | 2024 |
| D Cooper Ltd | Construction | 2019 |
| D E S Instrument Engineer Limited | Professional & scientific | 1989 |
| D H Textiles Ltd | Wholesale & retail | 2003 |
| D J Turfcare Equipment Limited | Wholesale & retail | 2005 |
| D Jones Rentals Limited | Real estate | 2019 |
| D Knight & Company Accountants Limited | Professional & scientific | 2006 |
| D L Ayres Limited | Health & social care | 2004 |
| D M Trade & Projects Limited | Administrative & support | 1988 |
| D R Bradbury Limited | Administrative & support | 2003 |
| D R Vault Limited | Information & communication | 2003 |
| D S Professional Builders Limited | Construction | 2020 |
| D T Editing | | 2002 |
| D Y Davies Europe Ukeig | | 1990 |
| D-Squared Design Limited | Professional & scientific | 1997 |
| D. a. S Build Limited | Construction | 2011 |
| D. Fudge & Sons Limited | Wholesale & retail | 1973 |
| D. Kilgallon (Richmond Windows) Limited | Wholesale & retail | 1977 |
| D.A.P. Construction Limited | Construction | 1998 |
| D.B. & P. Video Limited | | 1980 |
| D.F. Blackburne Properties Limited | Real estate | 1976 |
| D.F.A.O. Holdings Limited | Professional & scientific | 1998 |
| D.F.A.O. Limited | Other services | 1997 |
| D.H.Kim Limited | Health & social care | 2022 |
| D.J. Clark Limited | Transport & logistics | 2006 |
| D.R. Chick & Partners | | 1994 |
| D.R. Services (Surrey) Limited | Wholesale & retail | 2007 |
| D.S. Metals Limited | Extraterritorial | 2000 |
| D.W.D. Property and Investment Co. Limited | Construction | 1982 |
| D.W.D. Property Co. Limited | Construction | 1982 |
| D2D Projects Limited | Construction | 2005 |
| DAB Installations Limited | Construction | 2006 |
| Dacom Limited | Professional & scientific | 2006 |
| Daily Fresh Food Halal Meat Ltd | Hospitality | 2020 |
| Daimler Green Care Home Limited | Extraterritorial | 2005 |
| Daisy DM Limited | Professional & scientific | 2005 |
| Daisy's Place Limited | Other services | 2003 |
| Dakin Construction Limited | Construction | 1976 |
| Dakota Music Service Ltd | Information & communication | 1999 |
| Dalebond Finance International Limited | | 1980 |
| Dalegarth Industries Limited | Construction | 2006 |
| Dalepark Management Limited | Real estate | 1987 |
| Dallas Investments Limited | Real estate | 1984 |
| Dames Transport Ltd | Transport & logistics | 2019 |
| Damima Hygienix Limited | Wholesale & retail | 2004 |
| Danaz Healthcare Limited | Health & social care | 2004 |
| Dance Party London Limited | Arts & recreation | 2018 |
| Danesfield Preparatory School | Real estate | 1945 |
| Daniel Affum & Co Ltd. | Professional & scientific | 2004 |
| Daniel Wain Consulting Limited | Professional & scientific | 2007 |