| Complyme Ltd | Professional & scientific | 2016 |
| Composite Plastic Rubber Machinery Limited | Wholesale & retail | 2014 |
| Conavon Pianos Limited | Wholesale & retail | 2003 |
| Concept Gardens Ltd | Administrative & support | 2018 |
| Concise Media Consulting Limited | Professional & scientific | 2012 |
| Conex Portal Ltd | Administrative & support | 2020 |
| Connect the Dots Solutions Ltd | Administrative & support | 2023 |
| Connected VET Limited | Professional & scientific | 2013 |
| Constance Care & Support Ltd | Administrative & support | 2022 |
| Constructserv Ltd | Professional & scientific | 2016 |
| CONSULT25 Ltd | Information & communication | 2023 |
| Consultancy 1982 Limited | Professional & scientific | 2024 |
| Contexo Ltd | Information & communication | 2019 |
| Contract and Home Blinds Limited | Manufacturing | 1987 |
| Contract Employment Ltd | Administrative & support | 2012 |
| Control-Bridge Solutions Ltd | Professional & scientific | 2016 |
| Convenient Drain & Pipe Solutions Limited | Wholesale & retail | 2012 |
| Convey US Limited | Professional & scientific | 2015 |
| Conveyor Products Limited | Manufacturing | 1998 |
| Conway Collective Limited | Professional & scientific | 2025 |
| Cooke Securities Limited | Real estate | 1936 |
| Cookerhood Filter Limited | Other services | 2010 |
| Cooksey & SON Limited | Extraterritorial | 1945 |
| Cooksley & SON Limited | Extraterritorial | 1987 |
| Cool MAN Construction Limited | Construction | 2025 |
| Coolshock Limited | Extraterritorial | 2018 |
| Coombes & Sons(Bovey Tracey)Limited | Extraterritorial | 1965 |
| Coomera Limited | Health & social care | 2025 |
| Cooper Psychology Services Limited | Health & social care | 2021 |
| Coppered Wrench Ltd | Information & communication | 2021 |
| Coppice Garden Centre Limited | Wholesale & retail | 2012 |
| Coppice Lifestyle Limited | Wholesale & retail | 2025 |
| Copsewood Villas UK Ltd | Real estate | 2025 |
| Copthorne House Limited | Professional & scientific | 2023 |
| Core 300 Aston Wood Limited | Arts & recreation | 2020 |
| Core Energy Midlands Ltd | Construction | 2022 |
| Core View Ltd | Information & communication | 2025 |
| Corefit UK Promotions Limited | Information & communication | 2014 |
| Corefituk Ltd | Arts & recreation | 2011 |
| Corestax Software Ltd | Information & communication | 2026 |
| Corey Brennan Limited | Manufacturing | 2025 |
| CORI4N Ltd | Wholesale & retail | 2024 |
| Corkscrew Communications Limited | Professional & scientific | 2016 |
| Cornerstone Commercial Solutions Ltd | Financial services | 2012 |
| Corporate Continuity Ltd | Professional & scientific | 2018 |
| Corporate Strategic Services Limited | Professional & scientific | 1997 |
| Corporation Bloom Limited | Wholesale & retail | 2018 |
| Corral Running Ltd | Wholesale & retail | 2025 |
| Correctmove Limited | Real estate | 2010 |
| Corridan Properties Limited | Real estate | 2003 |
| Corswell Trade Ltd | Wholesale & retail | 2019 |
| Cortoke Investments Limited | Administrative & support | 2016 |
| Costa Fish Limited | Hospitality | 2011 |
| Costwise Cyber Limited | Information & communication | 2026 |
| Cosy Coffee Shop & Bruncherie Ltd | Hospitality | 2024 |
| Cotswold Valves Flow Control Limited | Manufacturing | 2022 |
| Cotswolds Enterprise Ltd | Real estate | 2025 |
| Cotswolds Soft Furnishings & Upholstery Limited | Manufacturing | 2023 |
| Cottams Associates Ltd | Administrative & support | 2011 |
| Cotterhill Hitchman LLP | | 2001 |
| Cotterill Civils Ltd | Financial services | 2016 |
| Cotterill Contractors Ltd | Construction | 2016 |
| Cotterill Drainage Limited | Construction | 2004 |
| Cottonwood Homes Ltd | Professional & scientific | 2017 |
| Couch Consulting Engineers (Midlands) Limited | Professional & scientific | 1992 |
| Couch Holdings Ltd | Financial services | 2020 |
| Cougar Power Ltd | Administrative & support | 2025 |
| Coughlan Properties Limited | Construction | 2016 |
| Coughlin Property Management Limited | Real estate | 2017 |
| Counties Crematorium Limited | Extraterritorial | 1980 |
| Course & Shelton Limited | Real estate | 2017 |
| Courtmart Limited | Extraterritorial | 1994 |
| Coventry Plant Sales Limited | Manufacturing | 2012 |
| Coverley Limited | Construction | 2007 |
| Coya Properties Limited | Real estate | 2026 |
| Coyne Brothers Limited | Extraterritorial | 1946 |
| CPC Academy Ltd | Transport & logistics | 2018 |
| CPC Construction Ltd | Construction | 2014 |
| Cpfa Consultancy Limited | Professional & scientific | 2008 |
| Cprm Holding Limited | Financial services | 2017 |
| CPS (WM) Limited | Construction | 2018 |
| CPW Roofing Ltd | Construction | 2025 |
| CR74 Ventures Ltd | Administrative & support | 2026 |
| CR8 Architectural Ltd | Professional & scientific | 2014 |
| CR8 Developments Ltd | Construction | 2016 |
| Crack Fixa Ltd | Other services | 2026 |
| Cradle and Bloom Ltd | Wholesale & retail | 2008 |
| Craftfab Limited | Manufacturing | 2019 |
| Cranfield FM Group Limited | Financial services | 2020 |
| Crawshaw Property Investments Limited | Administrative & support | 2015 |
| CRE8IVE Installations Ltd | Construction | 2016 |
| Create Building & Renovations Ltd | Construction | 2022 |
| Creative CNC Company Limited | Administrative & support | 2021 |
| Creative Devs Limited | Information & communication | 2025 |
| Creative Insight Limited | Professional & scientific | 2002 |
| Creative Minds Enrichment Ltd | Health & social care | 2026 |
| Creative PIE Films Ltd | Information & communication | 2015 |
| Creative Realty Limited | Real estate | 2020 |
| Creative Shades Limited | Wholesale & retail | 2010 |
| Creativsas Ltd | Wholesale & retail | 2019 |