| Celestial Properties (MB) Ltd | Real estate | 2023 |
| Cell City Kettering Limited | Wholesale & retail | 2019 |
| Cellfixkettering Limited | Wholesale & retail | 2023 |
| Cemade Ltd | Other services | 2013 |
| Cementex Ltd | Manufacturing | 2023 |
| Centurion Finance Partners Ltd | Financial services | 2025 |
| Centuryprint Limited | Manufacturing | 2002 |
| Ceraldi Motori Ltd | Extraterritorial | 2020 |
| Cereal Killers Limited | Extraterritorial | 2017 |
| Certification Services Limited | Professional & scientific | 2021 |
| Cezar Transport Services Ltd | Transport & logistics | 2022 |
| CF Health and Fitness Limited | Education | 2026 |
| CFW Accountants LLP | | 2009 |
| CG Automotive Limited | Wholesale & retail | 2016 |
| CG Maintenance 123 Ltd | Professional & scientific | 2026 |
| CG Property Sales Ltd | Real estate | 2025 |
| CGG Group Holdings (UK) Ltd | Wholesale & retail | 2016 |
| Chadwick Motorsport Limited | Arts & recreation | 2016 |
| Chalmers Property Investments Ltd | Real estate | 2022 |
| Chalta Ltd | Wholesale & retail | 2021 |
| Champagne & Confetti Wedding Car Hire Limited | Transport & logistics | 2014 |
| Champion Sealant Services Ltd | Construction | 2024 |
| Champion Supplies Ltd | Manufacturing | 2020 |
| Champs Heart Care Ltd | Health & social care | 2026 |
| Change Learning Ltd | Education | 2016 |
| Changetools Limited | Professional & scientific | 2015 |
| Channel Livestock Limited | Agriculture & fishing | 2008 |
| CHAOS2CALM Ltd | Health & social care | 2022 |
| Chaplins Carpentry Limited | Construction | 2013 |
| Character Properties Group Ltd | Financial services | 2024 |
| Chariots Carro Ltd | Wholesale & retail | 2025 |
| Chariots Cavallo Ltd | Wholesale & retail | 2025 |
| Chariots Specialist Cars Ltd | Wholesale & retail | 2011 |
| Charles Edward Properties Ltd | Administrative & support | 2017 |
| Charles Orlebar Estate Agents Limited | Real estate | 2003 |
| Charlie Perkins Limited | Extraterritorial | 2002 |
| Charlton-Cooper Limited | Administrative & support | 2008 |
| Chaseview Landscapes Limited | Administrative & support | 2022 |
| Chateau Limited | Professional & scientific | 1987 |
| Chattersthroughchapters Ltd | Arts & recreation | 2024 |
| Checkmate Automotive Ltd | Wholesale & retail | 2022 |
| Checkmate Enterprises Ltd | Administrative & support | 2024 |
| Cheese Store Direct Limited | Wholesale & retail | 2011 |
| Chelmsford Financial Management LLP | | 2006 |
| Chelsea Landscape Group Ltd | Administrative & support | 2025 |
| Chemi-Supply Limited | Wholesale & retail | 2012 |
| Chequer Board Limited | Real estate | 2020 |
| Cherry Apps Ltd | Extraterritorial | 2012 |
| Cherry Blossom Consulting Ltd | Information & communication | 2025 |
| Cherry Blossom Vintage Ltd | Wholesale & retail | 2025 |
| Chester and Newman Plumbing and Heating Services Ltd | Construction | 2010 |
| Chestnut Homeworks Limited | Real estate | 2026 |
| Cheyne Management Limited | Real estate | 1999 |
| Chickabooresturantgroup Ltd | Hospitality | 2025 |
| Child Funeral Charity | Other services | 2014 |
| Childs W Limited | Wholesale & retail | 2012 |
| Chillan Investments Ltd | Real estate | 2010 |
| Chilled Food Association Limited | Other services | 1991 |
| Chinese Kitchen Kettering Limited | Hospitality | 2025 |
| Chinfest CIC | Health & social care | 2025 |
| Chippy Couriers Limited | Transport & logistics | 2020 |
| Chirag Desai Architects Limited | Professional & scientific | 2021 |
| Chisholm Automotive Limited | Wholesale & retail | 2020 |
| Chiteg Ltd | Health & social care | 2022 |
| CHJ Properties LLP | | 2014 |
| Chocolate Seekers Limited | Hospitality | 2020 |
| Chopra and Sons Estates Ltd | Real estate | 2019 |
| Choules Partnership Limited | Professional & scientific | 2016 |
| CHP Finance Limited | Professional & scientific | 2017 |
| Chris George the Estate Agent Lettings LLP | | 2013 |
| Chris George the Estate Agent Sales LLP | | 2018 |
| Christian Day Nurseries Limited | Education | 2001 |
| Christie Doyle Creative Ltd | Professional & scientific | 2023 |
| Chroma Forge Ltd | Information & communication | 2025 |
| Chrysler Car Wash Limited | Wholesale & retail | 2022 |
| Churchlands Green Limited | Information & communication | 2022 |
| Ciko Ltd | Hospitality | 2026 |
| Circle Cubed Ltd | Information & communication | 2010 |
| Cirrus Control Systems Ltd | Professional & scientific | 2024 |
| CIS (Northampton) Limited | Manufacturing | 2004 |
| Cisco IT Solutions Ltd | Information & communication | 2026 |
| Citric Data Protection Limited | Information & communication | 2012 |
| City Cabs Conversions Limited | Wholesale & retail | 2011 |
| Citycall Services Limited | Wholesale & retail | 1997 |
| Civil Ceremonies Limited | Other services | 2002 |
| CJW Scaffolding Limited | Construction | 2021 |
| CK Transport Services Ltd | Transport & logistics | 2023 |
| CKM Services Ltd | Construction | 2026 |
| CL Property Holdings Ltd | Real estate | 2024 |
| Claireville Management Company Limited | Households | 2001 |
| Clare & Mike Property Limited | Real estate | 2017 |
| Clarendon Property Remedials Limited | Construction | 2025 |
| Clarendon UK Management Limited | Households | 2021 |
| Claret Seven Consulting Limited | Administrative & support | 2023 |
| Claridge Holdings Ltd | Extraterritorial | 2023 |
| Clarity First Ltd | Professional & scientific | 2025 |
| Classic 912 Limited | Real estate | 2008 |
| Classic Scan Limited | Manufacturing | 2018 |
| Clavex AI Solutions Limited | Information & communication | 2026 |
| Claxton Community CIC | Manufacturing | 2025 |