| CHHMT1 Limited | Administrative & support | 2023 |
| Chilli Digital Marketing Ltd | Professional & scientific | 2024 |
| Chiltern Property Holdings Limited | Construction | 2021 |
| China City (Bishop's Stortford) Ltd | Hospitality | 2026 |
| Chinnery's Flooring LLP | | 2017 |
| Chiro JOE Ltd | Health & social care | 2022 |
| Chloe Chai Ltd | Professional & scientific | 2022 |
| Chopped Limited | Information & communication | 2018 |
| Chris Higgins Limited | Information & communication | 2018 |
| Chris Russell Photography Ltd | Professional & scientific | 2023 |
| Chris Snow Architects Ltd | Professional & scientific | 2015 |
| CHRIS2 & Co Ltd | Real estate | 2022 |
| Christian Solidarity International | Extraterritorial | 1980 |
| CHRONO24 UK Ltd | Wholesale & retail | 2021 |
| Chuckles (UK) Limited | Health & social care | 2008 |
| Church Street Flats Ltd | Households | 2023 |
| Churchgate Interiors Limited | Construction | 2020 |
| Churton Management Company Limited | Households | 2011 |
| Chyrowski Studio Limited | Manufacturing | 2024 |
| Ciprocess Ltd | Extraterritorial | 2004 |
| Circadian FX Ltd | Financial services | 2017 |
| Citizen First Ltd | Information & communication | 2023 |
| City Car Scene Limited | Wholesale & retail | 2011 |
| Cityscape Konsult Construct Limited | Construction | 2008 |
| CJE Accountancy Services Ltd. | Professional & scientific | 2016 |
| CK Dental Health Clinic Ltd | Health & social care | 2014 |
| CK Digital Templates Ltd | Professional & scientific | 2024 |
| CKC Consultancy Ltd | Professional & scientific | 2024 |
| Clarity Biolife Limited | Wholesale & retail | 2015 |
| Clarity Biologics Limited | Wholesale & retail | 2009 |
| Clarity Global Group Limited | Wholesale & retail | 2002 |
| Clarity Pharma Ltd | Wholesale & retail | 1998 |
| Clark Accounts Limited | Professional & scientific | 2021 |
| Clark Carpentry Solutions Limited | Construction | 2022 |
| Clark Developers Limited | Construction | 2003 |
| Classique Boutique Limited | Wholesale & retail | 2024 |
| Clean Brite Spaces Limited | Other services | 2017 |
| Clear Sense Technologies Limited | Arts & recreation | 2023 |
| Clearpepper UK Limited | Information & communication | 2024 |
| Click & Roll CAD Ltd | Administrative & support | 2013 |
| Clifford Court (Grange Road) Limited | Other services | 2008 |
| Clifford-Burr LLP | | 2005 |
| Clissors Limited | Manufacturing | 2013 |
| CLM Health Ltd | Health & social care | 2014 |
| Clohh Ltd | Construction | 2025 |
| Cloud 9 Aviation Limited | Transport & logistics | 2024 |
| Cloud Accounting Solutions Ltd | Professional & scientific | 2024 |
| Cloud IT Consultancy London Ltd | Wholesale & retail | 2022 |
| Cls-Steel Ltd | Manufacturing | 2019 |
| Club Events Limited | Extraterritorial | 2025 |
| CM23 Scaffolding Ltd | Construction | 2016 |
| CMC Fabrications LLP | | 2003 |
| CMC Interiors Ltd | Professional & scientific | 2018 |
| CMC Mario Trans Ltd | Transport & logistics | 2025 |
| Co Clad Ltd | Construction | 2021 |
| Co.Create Art Direction Limited | Professional & scientific | 2023 |
| Coaching Law Limited | Professional & scientific | 2019 |
| Coaching Path Ltd | Other services | 2019 |
| Coachmind Consulting Ltd | Professional & scientific | 2016 |
| Coastwind Limited | Real estate | 1998 |
| Cobalt International Limited | Wholesale & retail | 2009 |
| Cocoa Trading Limited | Extraterritorial | 2009 |
| Code Visual Communications Ltd | Manufacturing | 2017 |
| Codebridge Consulting Ltd | Administrative & support | 2025 |
| Coggers Florists Limited | Wholesale & retail | 1985 |
| Cogido Ltd | Professional & scientific | 2008 |
| Cognitive Literacy Ltd | Professional & scientific | 2026 |
| Coke Consulting Limited | Professional & scientific | 2004 |
| Coke Gearing Consulting Ltd | Real estate | 2022 |
| Collar Brown Consultants Ltd | Other services | 2008 |
| Collins I.T Services Limited | Information & communication | 2016 |
| Colourful Communications Ltd | Professional & scientific | 2021 |
| Columbia Road Market Traders Group Ltd | Other services | 2020 |
| Community Initiative (Bishops Stortford) | Arts & recreation | 2005 |
| Company 0810 Ltd | Information & communication | 2026 |
| Completeness Limited | Other services | 2022 |
| Concil Ltd | Professional & scientific | 2023 |
| Connect 98 Limited | Administrative & support | 2022 |
| Connect Access Group Ltd | Construction | 2015 |
| Connect Fire and Security Services Limited | Administrative & support | 2023 |
| Connect Hire Ltd | Administrative & support | 2022 |
| Connect Scaffolding Limited | Construction | 1999 |
| Connect Scaffolding Systems Limited | Construction | 1999 |
| Connect Trustees Limited | Administrative & support | 2023 |
| Connected Through Art CIC | Wholesale & retail | 2026 |
| Consiliem Digital Limited | Information & communication | 2023 |
| Construct Design Management Ltd | Construction | 2009 |
| Construction and Foundations Ltd | Construction | 2020 |
| Construction Risks and Property Limited | Administrative & support | 2017 |
| Construction Talent Ltd | Administrative & support | 2024 |
| Consult and Grow Ltd | Professional & scientific | 2025 |
| Consultancyagp Limited | Professional & scientific | 2020 |
| Consulted Services Ltd | Professional & scientific | 2018 |
| Contexture Theatre Limited | Arts & recreation | 2013 |
| Continental Food Company (Holdings) Limited Ltd | Wholesale & retail | 2017 |
| Continental Wines Limited | Wholesale & retail | 1982 |
| Continuing Support Limited | Administrative & support | 2017 |
| Contract Security (UK) Ltd | Administrative & support | 2012 |
| Contract Security Training Ltd | Education | 2012 |
| Conway Landscapes (UK) Limited | Administrative & support | 2011 |