| Cashify Tech Ltd | Wholesale & retail | 2024 |
| Cassama Home Sense Limited | Wholesale & retail | 2025 |
| Castle Estates (Essex) Limited | Real estate | 1996 |
| Castle Estates Limited | Real estate | 1995 |
| Castle Marquees Limited | Administrative & support | 1999 |
| Castle Pond Management Company Limited | Households | 2003 |
| Castle Supermarkets Limited | Transport & logistics | 1988 |
| Castle Supplies Limited | Wholesale & retail | 1999 |
| Castlebury Limited | Other services | 2022 |
| Castlemere Aquariums Limited | Administrative & support | 1994 |
| Cater Willis Limited | Financial services | 2005 |
| Cava Projects Limited | Construction | 2023 |
| Cavendish Investments Limited | Financial services | 1982 |
| Cavesold Limited | Wholesale & retail | 1988 |
| CB Fred-Andre Ltd | Information & communication | 2017 |
| CB Riches Limited | Construction | 2026 |
| Cbac Services Ltd | Energy | 1997 |
| CBD X OIL Ltd | Wholesale & retail | 2024 |
| CBR (Essex) Limited | Construction | 2007 |
| Ccfo Limited | Transport & logistics | 2016 |
| CCM Construction Services Ltd | Construction | 2024 |
| Cdkl Ltd | Information & communication | 2023 |
| CDO Sushi Limited | Other services | 2021 |
| CDR Brothers Ltd | Wholesale & retail | 2026 |
| Cedar Construction (UK) Limited | Construction | 1995 |
| Cedar Electrical Limited | Wholesale & retail | 1969 |
| Cedartree Ventures Limited | Professional & scientific | 2003 |
| Celestial Global Entertainments Limited | Information & communication | 1997 |
| Celior Ltd | Wholesale & retail | 2026 |
| Cellmarket Limited | Wholesale & retail | 2021 |
| Centra Businesses Limited | Wholesale & retail | 2002 |
| Central Blinds Limited | Administrative & support | 2003 |
| Central Conversions (Builders & Decorators) Limited | | 1964 |
| Central Markets Investment Management Limited | Administrative & support | 2007 |
| Centre Engineering Services Limited | Professional & scientific | 1990 |
| Ceresderma Limited | Wholesale & retail | 2025 |
| Ceri Valley Orchards Limited | Agriculture & fishing | 2007 |
| Cerulean Solutions Limited | Information & communication | 1999 |
| Ceruleany Ltd | Wholesale & retail | 2025 |
| Ceso Limited | Other services | 2000 |
| Cesurbarbers Ltd | Other services | 2023 |
| Ceylon Street Ltd | Hospitality | 2026 |
| CFL Planning & Building Design Limited | Real estate | 2003 |
| CGA Healthcare Engineering Services Limited | Professional & scientific | 1996 |
| Cgem Group Ltd | Health & social care | 2026 |
| Chads Farm Energy Centre Limited | Energy | 2020 |
| Chadwell Commercials Ltd | Real estate | 2014 |
| Chafford Lang Utilities Limited | Construction | 2002 |
| Chaiki Retail Ltd | Wholesale & retail | 2024 |
| Chain Credit Brokers Limited | | 1988 |
| Chairbook Ltd | Information & communication | 2026 |
| Chalkwell Lodge Limited | Real estate | 1959 |
| Chalkwell Pet Foods Limited | Wholesale & retail | 2005 |
| Challis Autos Ltd | Professional & scientific | 2006 |
| Chambers Property Maintenance Ltd | Construction | 2023 |
| Chameleon Direct Limited | Extraterritorial | 2007 |
| Chameleon Holidays and Travel Limited | Administrative & support | 2008 |
| Chameleondirect.Com Limited | Extraterritorial | 2007 |
| Champers Inns Limited | | 1980 |
| Chan Real Estate Ltd | Real estate | 2018 |
| Chanan Sangha Group Holdings Ltd | Real estate | 2025 |
| Chander Jatala Limited | Administrative & support | 2024 |
| Chandler Material Supplies Limited | Wholesale & retail | 1980 |
| Chandpuri House Ltd | Hospitality | 2013 |
| Change Your Mind Limited | Health & social care | 2003 |
| Chantasha Consultancy Limited | Information & communication | 2007 |
| Chantra Thai Therapy Ltd | Health & social care | 2025 |
| Chapel & Chapel Auctions Ltd | Administrative & support | 1995 |
| Chapellas GSD Ltd | Professional & scientific | 2025 |
| Chaplin Antiques | | 1994 |
| Chapman Contractors (Kent) Limited | Construction | 2006 |
| Chapple Accounting Services Ltd | Professional & scientific | 2008 |
| Chapter 2 Construction Ltd | Construction | 2025 |
| Chapungu 3 Limited | Health & social care | 2019 |
| Charing Associates Limited | Professional & scientific | 2003 |
| Chariots (Romford) Ltd | Wholesale & retail | 2002 |
| Charles Mckenzie Associates Limited | Administrative & support | 2003 |
| Charles Portway & Son,Limited | | 1938 |
| Charlie Laboratory Ltd | Manufacturing | 2024 |
| Charlie Welding & Fabrication Ltd | Construction | 2024 |
| Charter House Manby Ltd | Real estate | 2021 |
| Charterfield Homes Limited | Construction | 2003 |
| Charterhouse Design & Build Limited | Construction | 2003 |
| Charworth Limited | Wholesale & retail | 2008 |
| Chase Bureau Directors Self Assessment Limited | Professional & scientific | 2000 |
| Chateau (Romford) Limited | Hospitality | 2010 |
| Chaudhary Haseeb Prime Ltd | Wholesale & retail | 2025 |
| Chaudhary Holdings Limited | Real estate | 2016 |
| Cheatcode Media Group Ltd | Information & communication | 2021 |
| Cheddatech Ltd | Information & communication | 2025 |
| Chela ENG Ltd | Construction | 2003 |
| Chellcorp Ltd | Arts & recreation | 2016 |
| Chelmer Analysis and Design Limited | Information & communication | 2013 |
| Chelmer Company Services Limited | Professional & scientific | 1998 |
| Chelmer Construction Consultants Limited | Professional & scientific | 2003 |
| Chelmsford Business Leaders Ltd | Extraterritorial | 2004 |
| Chelmsford Counselling Foundation | Health & social care | 2001 |
| Chelmsford Diocesan Board of Finance(The) | Other services | 1914 |
| Chelmsford Mortgage Solutions Limited | Financial services | 2004 |
| Chelmsford Spirtualist Society Limited | Other services | 1948 |