| County Lofts Limited | | 1992 |
| Coupleward Limited | | 1982 |
| Courier Movements Limited | Transport & logistics | 1996 |
| Courtenay Consulting Limited | Professional & scientific | 2023 |
| Courtleigh Property Holdings Limited | Real estate | 1994 |
| COX & Readman Garages Limited | Real estate | 1980 |
| CP Capital Limited | Real estate | 2019 |
| CPK Management Limited | Professional & scientific | 2005 |
| Cradle Healthcare Limited | Health & social care | 2018 |
| Cramond Associates | | 1988 |
| Crane Technology Limited | Information & communication | 2001 |
| Crane Wexelblatt Entertainment Limited | Information & communication | 1994 |
| Cranflats Limited | Professional & scientific | 1983 |
| Craven Court (Southall) Residents Association Limited | Households | 1978 |
| Craven EYE Plumbing & Heating Suppliers Limited | Wholesale & retail | 2000 |
| Cravenshield Services Limited | | 1982 |
| Crawford Design Limited | Professional & scientific | 2001 |
| Crealis Labs Ltd | Information & communication | 2019 |
| Creating Business Opportunities Limited | Administrative & support | 2000 |
| Creating Opportunities Limited | Administrative & support | 2000 |
| Creative Performance Limited | Arts & recreation | 1996 |
| Crescent Barber Ltd | Other services | 2020 |
| CREST2CARE Recruitment Ltd | Health & social care | 2025 |
| Crestadrive Limited | Households | 1991 |
| Crewa Limited | Professional & scientific | 2005 |
| Criminology in the Millennium Limited | Information & communication | 2001 |
| Crome Properties Limited Liability Partnership | | 2022 |
| Cromwell Accountants Limited | Professional & scientific | 1995 |
| Cromwell Security & Fire Services Limited | Administrative & support | 1987 |
| Crookster (Holdings) Limited | Professional & scientific | 2009 |
| Crookster Limited | Real estate | 2002 |
| Crossways Property Limited | Extraterritorial | 2003 |
| Crown Productions Limited | Information & communication | 2018 |
| Crownfern Limited | Hospitality | 2002 |
| Crowninvest Limited | Real estate | 2019 |
| Crownlodge Developments Limited | Construction | 2007 |
| Crownplex Limited | Real estate | 2007 |
| Crowns Investments Limited | Real estate | 1998 |
| Crownstone Properties PLC | | 1987 |
| Crystal Vista Limited | Administrative & support | 2011 |
| Csdp Cambridge Limited | Information & communication | 2017 |
| Cube Contracting Limited | Construction | 2007 |
| Cube Design and Build Limited | Construction | 2003 |
| Cunningham Leisure Limited | | 1984 |
| Curfin Properties (UK) Limited | Real estate | 1981 |
| Curious Works Limited | Information & communication | 2005 |
| Currans (U.K.) Ltd | Transport & logistics | 1990 |
| Currie Easy Self Storage Limited | Transport & logistics | 1972 |
| Currie Finance and Leasing Company Limited | Real estate | 1972 |
| Currie Leasing Limited | Financial services | 1978 |
| Currie Motors Kingston Limited | Real estate | 1974 |
| Currie Motors Limited | Real estate | 1979 |
| Currie Motors UK Limited | Wholesale & retail | 1989 |
| Curtain Best Limited | Administrative & support | 2009 |
| Curvepolite Limited | | 1987 |
| Curzon Catering Co. Limited | | 1984 |
| Custom Solutions Limited | Construction | 2003 |
| Customer Care Solutions (UK) Limited | Information & communication | 2005 |
| Cutterboy Films Ltd. | Information & communication | 2006 |
| CXO Research Limited | Information & communication | 2003 |
| Cyberdyne Technologies Limited | Information & communication | 1997 |
| Cyclos Limited | Other services | 2011 |
| D & B Construction Limited | Real estate | 2004 |
| D & F Properties Limited | Construction | 1990 |
| D & J Ambrose Limited | Other services | 2001 |
| D & S Evans Limited | Wholesale & retail | 1999 |
| D & Sons Properties Ltd. | Real estate | 2021 |
| D & V Enterprises Limited | Wholesale & retail | 1997 |
| D a Haulage Limited | Transport & logistics | 2007 |
| D P M Consultancy Limited | Information & communication | 1998 |
| D Rahman Properties Ltd | Real estate | 2025 |
| D S K Properties Limited | Real estate | 1991 |
| D&D Brasseria Ltd | Hospitality | 2022 |
| D&M Security Ltd | Other services | 2017 |
| D&S Personnel Ltd | Administrative & support | 2007 |
| D'Artagnan Productions Limited | Information & communication | 2000 |
| D. Nolan Construction Limited | Construction | 1994 |
| D.A.Ductwork Ltd | Construction | 2006 |
| D.J.Squire Property and Investment Company Limited | Real estate | 1962 |
| D.Popescu.Ltd | Construction | 2005 |
| D.W. Construction (UK) Limited | Construction | 1997 |
| D3S Medical Solutions Limited | Health & social care | 2007 |
| DAB Construction Services Limited | Construction | 2007 |
| Daeneryss Ltd | Education | 2020 |
| Dafcon Haulage Limited | Transport & logistics | 2007 |
| DAG Commercial Ltd | Other services | 2012 |
| Daimler Hire Limited | Professional & scientific | 1932 |
| Dalsons Limited | Information & communication | 2006 |
| Damans Collections Limited | Wholesale & retail | 2001 |
| DAN Dewsbury Films Ltd | Information & communication | 2022 |
| Dani Consultants Ltd | Information & communication | 2001 |
| Danny the Dog Limited | Information & communication | 2002 |
| Dapa Property Investments Limited | Real estate | 2007 |
| Dapper Services Limited | Wholesale & retail | 2017 |
| Dapsons EK Ltd | Professional & scientific | 2021 |
| Darbari Fancy Textiles (UK) Limited | Wholesale & retail | 1999 |
| Darragh. Parker | | 1998 |
| Dasco (Wholesale) Limited | Wholesale & retail | 1986 |
| Dasco Investment Corporation Limited | Wholesale & retail | 1980 |
| Dashwise Limited | Wholesale & retail | 2000 |