| Cawdor Capital (Hopwood) Limited | Real estate | 2010 |
| Ccrumbs Ltd | Hospitality | 2025 |
| Cdeymedi UK Ltd | Professional & scientific | 2016 |
| CDM Gardens Ltd | Administrative & support | 2025 |
| Cedars Equestrian Ltd | Agriculture & fishing | 2006 |
| CEI Professional Services Limited | Professional & scientific | 2025 |
| Celette UK Limited | Wholesale & retail | 2009 |
| Central Food and Wine Daventry Ltd | Wholesale & retail | 2019 |
| Central Storage & Logistics Ltd | Administrative & support | 2016 |
| Central Way Garage Ltd | Transport & logistics | 2003 |
| Centre 11 Management Company Limited | Real estate | 2003 |
| Centuraheat Ltd | Wholesale & retail | 2026 |
| Ceoclub Limited | Other services | 2021 |
| CFG Project Consulting Limited | Professional & scientific | 2023 |
| CG Emporium Ltd | Wholesale & retail | 2023 |
| CH Supply Chain Services Limited | Professional & scientific | 2019 |
| Chapel 4 ALL Community Interest Company | Wholesale & retail | 2022 |
| Charity Samuel Bridal Limited | Wholesale & retail | 2020 |
| Charlie Fagg Racing Ltd | Arts & recreation | 2019 |
| Chase Properties and Investments Limited | Households | 2022 |
| Chassis Craft Ltd | Manufacturing | 2024 |
| Chefsrange Limited | Manufacturing | 1999 |
| Cherwell Ironwork Limited | Manufacturing | 2002 |
| CHH Planning Limited | Financial services | 2018 |
| Chihuaccino Ltd | Hospitality | 2025 |
| Child&You Ltd | Health & social care | 2023 |
| China House Chinese Ltd | Hospitality | 2024 |
| China Tobacco (Hongkong) Limited | Manufacturing | 2020 |
| Chip&Anna Services Ltd | Construction | 2020 |
| Chipper Carpentry Ltd | Manufacturing | 2019 |
| Chjonn Studios Ltd | Information & communication | 2017 |
| Chlemount Control (UK) Limited | Professional & scientific | 2017 |
| Choppers Trans Ltd | Transport & logistics | 2024 |
| Chris Holder UK Limited | Arts & recreation | 2012 |
| Christian Expedition Ltd | Transport & logistics | 2013 |
| Christin Design Limited | Manufacturing | 2015 |
| Christopher Autos Ltd | Wholesale & retail | 2025 |
| Chryso UK Limited | Extraterritorial | 1989 |
| Church END Independent Services Ltd | Professional & scientific | 2019 |
| Church Road Limited | Real estate | 2018 |
| Churchleys Limited | Administrative & support | 2023 |
| CID (UK) Limited | Professional & scientific | 2006 |
| CIK Financial Ltd | Financial services | 2019 |
| Cimentalia (UK) Limited | Construction | 2017 |
| Cinders Cleaning Solutions Ltd | Administrative & support | 2015 |
| Cinesocial UK Limited | Arts & recreation | 2015 |
| CJ Bookkeeping Ltd | Professional & scientific | 2016 |
| CJ Hospitality Solutions Ltd | Arts & recreation | 2024 |
| CJA Building Services Ltd | Construction | 2020 |
| CJC Projects Ltd | Professional & scientific | 2017 |
| Ckdistributions Limited | Wholesale & retail | 2025 |
| Claire Mcdonald Ltd | Health & social care | 2025 |
| Clarity Vision Limited | Extraterritorial | 2013 |
| Clarke & Adkins Ltd | Manufacturing | 2023 |
| Classic Range Cookers Ltd | Wholesale & retail | 2001 |
| Claxmont Real Estate Ltd | Real estate | 2023 |
| Clean Air Facilities Limited | Construction | 2000 |
| Clean Air Installations Limited | Construction | 2000 |
| Clean Air Technology Ltd. | Professional & scientific | 1992 |
| CLF Logistics Ltd | Transport & logistics | 2024 |
| Clive Winslow Limited | Administrative & support | 2000 |
| Cloveria Megelli Ltd | Professional & scientific | 2014 |
| CMV Construction Ltd | Construction | 2025 |
| Coffee Classics Limited | Wholesale & retail | 2007 |
| Coherent (UK) Financing CP Ltd | Financial services | 2024 |
| Coherent (UK) Financing Ltd | Professional & scientific | 2023 |
| Coherent (UK) Holdings B Ltd | Professional & scientific | 2023 |
| Coherent (UK) Holdings C Ltd | Professional & scientific | 2023 |
| Coherent (UK) Holdings Limited | Professional & scientific | 1997 |
| Coherent (UK) Limited | Professional & scientific | 1970 |
| Cohersa Industries U.K. Limited | Wholesale & retail | 2019 |
| Collisian Hospitality Limited | Hospitality | 2024 |
| Combine Rescue Ltd | Manufacturing | 2022 |
| Community Action Northants Limited | Information & communication | 2005 |
| Competent Construction People Ltd | Construction | 2025 |
| Conker Mental Health Ltd | Education | 2023 |
| Constant Systems Limited | Manufacturing | 1989 |
| Construction Asset Maintenance (CAM) Ltd | Construction | 2014 |
| Consumer Direct Ltd | Wholesale & retail | 2011 |
| Contour Golf Limited | Construction | 1999 |
| Conveyor Accessories Direct Limited | Manufacturing | 2007 |
| Coombe Holdings Limited | Financial services | 2019 |
| Copestake Workshop Supplies Limited | Wholesale & retail | 2011 |
| Core Community Retail (Developments) Limited | Construction | 2021 |
| Core Community Retail (UK) Limited | Professional & scientific | 2020 |
| Cornish Properties Limited | Construction | 2018 |
| Cosy Trading Limited | Construction | 2015 |
| Cotswold Colour Matters Limited | Construction | 2006 |
| Cotswold Homestead Ltd | Administrative & support | 2022 |
| Cottage Autos Ltd | Wholesale & retail | 2023 |
| Cottons Accountants LLP | | 2010 |
| Cottons Holdings Limited | Financial services | 2018 |
| Cottons Wealth Management Limited | Professional & scientific | 2018 |
| Counselling Dobson Ltd | Health & social care | 2025 |
| COX Scaffolding Ltd | Construction | 2025 |
| CP Accounting Services Limited | Professional & scientific | 2006 |
| CPM Technical Services Limited | Administrative & support | 2001 |
| Crael Group Ltd | Professional & scientific | 2006 |
| Crankshaft Coffee Limited | Hospitality | 2024 |
| CRC Recruitment Ltd | Administrative & support | 2013 |