| Cars for Cash Ltd | Wholesale & retail | 2014 |
| Carter Lane Estate Management Limited | Real estate | 2024 |
| Carvers Contractors Ltd | Construction | 2025 |
| Casey&Co Estates Ltd | Real estate | 2026 |
| Casper Consulting Limited | Information & communication | 2019 |
| Cassandrat Limited | Health & social care | 2015 |
| Cast Data Ltd | Information & communication | 2018 |
| Castle Point Home Improvements Limited | Construction | 2026 |
| Castlelane Management Company Limited | Real estate | 1985 |
| Castleridge Group Ltd | Construction | 2026 |
| Cat D Salvage Ltd | Wholesale & retail | 2021 |
| Cat D Vans Ltd | Wholesale & retail | 2021 |
| Catholic Unscripted Ltd | Information & communication | 2023 |
| Catterick Black Consulting Limited | Professional & scientific | 2021 |
| Cavolini Limited | Wholesale & retail | 2025 |
| Caya Space Ltd | Wholesale & retail | 2026 |
| Caya Space Publishing Ltd | Information & communication | 2026 |
| Caysure Digital Limited | Information & communication | 2015 |
| Caytons Claims Limited | Financial services | 2015 |
| CB Marine Services Ltd | Manufacturing | 2022 |
| CBD Cafe Ltd | Manufacturing | 2018 |
| CBW Building Services Ltd | Construction | 2019 |
| CC Developments (London) Limited | Construction | 2007 |
| CC Leigh on Sea Limited | Hospitality | 2025 |
| CC Martek Limited | Manufacturing | 2002 |
| Ccmeck Services Ltd | Administrative & support | 2013 |
| CCS Services Group Ltd | Water & waste | 2024 |
| CDA Ascot Limited | Construction | 2024 |
| CDR Access Ltd | Real estate | 2018 |
| CDX Digital Ltd | Professional & scientific | 2016 |
| CE Coaching Ltd | Arts & recreation | 2021 |
| Cellar Wine Bar Limited | Hospitality | 2018 |
| Cemd Consulting Ltd | Administrative & support | 2017 |
| Cennet (UK) Limited | Construction | 2007 |
| Central Audio Visual Solutions Ltd | Information & communication | 2012 |
| Central Cars (Leigh) Limited | Wholesale & retail | 2004 |
| Central Cars Trade Ltd | Wholesale & retail | 2019 |
| Central London IT Consultancy Services Limited | Information & communication | 2007 |
| Centricity Holdings Ltd | Financial services | 2026 |
| Centurion Prime Consulting Limited | Information & communication | 2021 |
| Century Sporting Services Limited | Arts & recreation | 1994 |
| Ceramtech Limited | Health & social care | 2003 |
| Certsafe Limited | Information & communication | 2025 |
| CES Consultancy Services Limited | Construction | 2018 |
| CG Business Sales Ltd | Wholesale & retail | 2024 |
| CGS London Limited | Information & communication | 2018 |
| Chaffinch Lodge RTM Company Limited | Households | 2023 |
| Chalkwell Accountants Ltd | Professional & scientific | 2018 |
| Chalkwell Consulting Limited | Professional & scientific | 2007 |
| Chalkwell Park Motors Limited | Wholesale & retail | 2014 |
| Chambers Construction Group Ltd | Construction | 2022 |
| Chambers Investment Group Limited | Construction | 2025 |
| Chandlers Consultancy Limited | Construction | 2017 |
| Chandos Hair Stylists Ltd | Other services | 2015 |
| Changes Property Solutions Ltd | Real estate | 2022 |
| Chant Property Development Limited | Real estate | 2021 |
| Chaos & Calm CIC | Health & social care | 2020 |
| Chapmans Construction Essex Ltd | Construction | 2024 |
| Charcoal BBQ Maze Grill Ltd | Hospitality | 2024 |
| Charfleet Powder Coatings Ltd | Construction | 2012 |
| Charfleets Supplies Limited | Construction | 2018 |
| Charles Hancock Limited | Construction | 2009 |
| Charli Copping Limited | Other services | 2017 |
| Charlotte Cole Skincare Ltd | Other services | 2023 |
| Charlotte Spooner Ltd | Arts & recreation | 2012 |
| Charsley Stewart Limited | Administrative & support | 2006 |
| Chartstream Limited | Extraterritorial | 2023 |
| Chase Aero Limited | Professional & scientific | 2020 |
| Chawkwell Nova Ltd | Construction | 2024 |
| CHE GFX Ltd | Professional & scientific | 2020 |
| Check Mate - Property Reports Ltd | Real estate | 2024 |
| Checkify Technologies Limited | Information & communication | 2026 |
| Chelcombe Limited | Professional & scientific | 2018 |
| Chelmer Contract Services Limited | Construction | 1997 |
| Chelmsford City Construction Ltd | Construction | 2012 |
| Chelmsford City Plumbing and Heating Limited | Construction | 2017 |
| Chelmsford Demolition Limited | Administrative & support | 2022 |
| Chelmsford Dwellings Holdings Ltd | Real estate | 2024 |
| Chelmsford Dwellings Ltd | Construction | 2021 |
| Chelmsford Radio Limited | Information & communication | 2008 |
| Chemia Limited | Real estate | 2023 |
| Cherries Ltd | Other services | 2026 |
| Cherry Weir Management Ltd | Real estate | 2025 |
| Cherryclicks Marketing Limited | Information & communication | 2024 |
| Cherryred Contracts Limited | Construction | 2012 |
| Chestnut Consultancy Limited | Professional & scientific | 2023 |
| Chestnut Walk (Blocks a B C) Flat Management Company Limited | Households | 1995 |
| Chestnut Walk (Blocks Defghjk) Flat Management Company Limited | Households | 1997 |
| Chestnut Walk (Blocks Lmnpq) Flat Management Company Limited | Households | 1996 |
| Chestnut Walk (Blocks Rstuvw) Flat Management Company Limited | Households | 1996 |
| Chestnut Walk Residents Association Limited | Households | 1995 |
| Chignal Facilities Management Limited | Construction | 2014 |
| Chignal Holdings Limited | Construction | 2013 |
| Chill Southend CIC | Education | 2023 |
| Chilli Republic Ltd | Manufacturing | 2020 |
| Chimes House Freehold Limited | Households | 2014 |
| Chin Chin LOS Limited | Hospitality | 2022 |
| Chique Leigh on Sea Limited | Other services | 2016 |
| Chita Shop Ltd | Other services | 2019 |
| Chivers Estates Limited | Real estate | 2020 |