| Catering Delight Limited | Hospitality | 2017 |
| Cathedral Stoneworks Chichester Limited | Construction | 2014 |
| Catherine Rowlands Ltd | Health & social care | 2025 |
| Cats Tyres Ltd | Wholesale & retail | 2014 |
| Cavanaugh Group Ltd | Professional & scientific | 2018 |
| Caxton House Flats Limited | Real estate | 2009 |
| CBF Steelworks & Entrances Ltd | Construction | 2026 |
| CBR Driving Ltd | Construction | 2014 |
| CC Design and Delivery UK Ltd | Professional & scientific | 2023 |
| CDM Projects Limited | Manufacturing | 2021 |
| CDT Group Holdings Limited | Administrative & support | 2022 |
| Cecilia Homes Ltd | Real estate | 2021 |
| CEG Electrical Contractors Limited | Construction | 2018 |
| Celia Birtwell Consultants Limited | Professional & scientific | 2003 |
| Cellan Limited | Administrative & support | 2001 |
| Cellars Direct Ltd | Wholesale & retail | 2019 |
| Cente Properties Ltd | Real estate | 2017 |
| Central Hub for Business Limited | Professional & scientific | 2020 |
| Central Service (Wickford) Limited | Other services | 2002 |
| Centre Cafe Limited | Hospitality | 1998 |
| Century 21 Building Services Limited | Construction | 2017 |
| Certifier Ltd | Construction | 2014 |
| Cesan Ltd | Hospitality | 2022 |
| CG Electrical Core Ltd | Construction | 2026 |
| CG Tiling Limited | Construction | 2023 |
| CG Utilities & Landscaping Ltd | Construction | 2020 |
| Cgsw Shared Housing Limited | Real estate | 2024 |
| Cgsw Single Lets Limited | Real estate | 2024 |
| CH & B Repair Services Limited | Construction | 2017 |
| CH Estate Management Limited | Real estate | 2007 |
| CH4B Limited | Professional & scientific | 2020 |
| Chainbridge Limited | Information & communication | 2022 |
| Chalk Street Consulting Limited | Information & communication | 2017 |
| Chambers Manor Mews Management Limited | Households | 2013 |
| Champion Safety Limited | Other services | 2000 |
| Chandlers Corporate Flowers Ltd | Wholesale & retail | 2021 |
| Chapel (Sheering) Management Company Limited | Households | 2026 |
| Chapman Installations Limited | Construction | 2007 |
| Chapman's Architecture Limited | Professional & scientific | 2018 |
| Charfleets Car Centre Limited | Wholesale & retail | 1998 |
| Charles Chapman Ltd | Administrative & support | 2016 |
| Charles Electrical Ltd. | Construction | 2004 |
| Charles MAE Developments Ltd | Construction | 2019 |
| Charles MAE Group Limited | Real estate | 2026 |
| Charles MAE Holdings Limited | Real estate | 2020 |
| Charles Thomas Heritage Fire Protection Specialists Ltd | Construction | 2020 |
| Charlotte Borg Ltd | Arts & recreation | 2019 |
| Charly's Media Ltd | Information & communication | 2014 |
| Charmers Barber Shop Limited | Other services | 2024 |
| Cheaper Cleaning Essentials Ltd | Wholesale & retail | 2025 |
| Cheapest Clearance Limited | Water & waste | 2025 |
| Chelmerbridge Ltd | Wholesale & retail | 2018 |
| Cherie’S Auto Driving School Ltd | Education | 2025 |
| Cheshire Fillers (UK) Limited | Professional & scientific | 2011 |
| Cheshire Fillers Limited | Manufacturing | 2003 |
| Chestnut Lighting Limited | Manufacturing | 2007 |
| Chic Media Ltd | Professional & scientific | 2017 |
| Chicken Vips Limited | Hospitality | 2025 |
| Chickike Limited | Health & social care | 2017 |
| Childerditch MOT Centre Ltd | Wholesale & retail | 2020 |
| Childs Property Investments Limited | Construction | 2020 |
| Childs Property Limited | Real estate | 1996 |
| Chip N Jerk Holloway Ltd | Hospitality | 2024 |
| CHM Roofing Ltd | Construction | 2024 |
| Chop Shop Butchery Ltd | Wholesale & retail | 2024 |
| Chris Brooks Media Ltd | Information & communication | 2017 |
| Churchill Property Innovations Ltd | Real estate | 2016 |
| Chy-Best Ltd | Health & social care | 2022 |
| Cila Property Ltd | Real estate | 2022 |
| Cima Telecom Limited | Wholesale & retail | 2017 |
| Circle Maintenance Limited | Construction | 2021 |
| Circle Scaffolding Services Limited | Construction | 2021 |
| City Company Seals Limited | Manufacturing | 1973 |
| City of London Ironmongers Ltd | Administrative & support | 2016 |
| Civilpack Limited | Professional & scientific | 1996 |
| CJ Morrison Limited | Construction | 2011 |
| CJB Security Ltd | Administrative & support | 2023 |
| CJS Helicopters Limited | Administrative & support | 2020 |
| CJS Sales & Services Limited | Wholesale & retail | 2010 |
| CK Swift Supply Limited | Financial services | 2024 |
| CL3 Digital Ltd | Information & communication | 2019 |
| Clarel Capital Limited | Administrative & support | 2014 |
| Claritas Advisory Ltd | Administrative & support | 2026 |
| Clarity Consulting Solutions Ltd | Professional & scientific | 2014 |
| Clarke & Sons Trading Ltd | Hospitality | 2023 |
| Clarke Construction (Essex) Limited | Construction | 2011 |
| Clarke Hillyer Limited | Administrative & support | 1999 |
| Clarke Stone Construction Limited | Construction | 2019 |
| Clarke's Stone and Ceramic Limited | Construction | 2016 |
| Classic PUB Dining (OKH) Ltd | Hospitality | 2019 |
| Classic PUB Dining Ltd | Hospitality | 2019 |
| Clay IT Consulting Limited | Information & communication | 2026 |
| CLC Entertainment Ltd | Wholesale & retail | 2016 |
| Clcessex Ltd | Manufacturing | 2021 |
| Clcprints Ltd | Manufacturing | 2025 |
| Clean Slate Roofing Specialist Ltd | Construction | 2025 |
| Cleaning With Meaning (Essex) Limited | Administrative & support | 2025 |
| Cleveleigh Limited | Hospitality | 2019 |
| Climate Save Renewables Ltd | Construction | 2015 |
| Clinical Healthcare Solutions Limited | Health & social care | 2017 |