| Chopsticks Delight Limited | Hospitality | 2026 |
| Chris Bailey Services Ltd | Professional & scientific | 2025 |
| Chris Byrne Associates Limited | Professional & scientific | 2005 |
| Chris Luck Consulting Ltd | Professional & scientific | 2024 |
| Chris Ryan Golf Ltd | Arts & recreation | 2021 |
| Christopher Jonathan Clarke Ltd | Extraterritorial | 2025 |
| Christopher Pullen Limited | Professional & scientific | 2020 |
| Christopher Taylor Property Company Limited | Real estate | 2001 |
| Christy Hydraulics (Warwick) Limited | Wholesale & retail | 2003 |
| Chrusciel Property Ltd | Real estate | 2026 |
| Church Farm Brewery Ltd | Manufacturing | 2015 |
| Church Farm Dairy Limited | Real estate | 2007 |
| Church Rise (Ipsley Church Lane) Management Company Limited | Households | 2026 |
| Churchill Mergers & Acquisitions Limited | Professional & scientific | 2024 |
| Churn Valley (Monmouth) Limited | Real estate | 1986 |
| Ciba Aviation Limited | Financial services | 2016 |
| Cigma Holdings Limited | Information & communication | 2023 |
| Cimcorp UK Ltd | Information & communication | 2022 |
| Cincin London Limited | Professional & scientific | 2020 |
| Cinder Tree Ltd | Real estate | 2025 |
| CIO Connect Limited | Other services | 2007 |
| Cipher Arena Corp Ltd | Information & communication | 2024 |
| Cipher Corp Holding Ltd | Information & communication | 2014 |
| Cipher Corp Management Ltd | Arts & recreation | 2016 |
| Circonyx Ltd | Wholesale & retail | 2026 |
| Cisco Contracts Ltd | Information & communication | 2019 |
| Civil Redress Ltd | Administrative & support | 2021 |
| Civils and Utilities Limited | Construction | 2013 |
| CJ Wilson Touring Ltd | Administrative & support | 2018 |
| Cj's Events Warwickshire Limited | Wholesale & retail | 2015 |
| CJT Fencing & Landscaping Limited | Construction | 2021 |
| CJT Interiors Limited | Other services | 2018 |
| CKD (Scotland) Limited | Real estate | 1999 |
| CKD Limited | Real estate | 2016 |
| Clacton Property Investments Limited | Real estate | 2006 |
| Cladd Media Limited | Information & communication | 2006 |
| Clairsigh Consulting Ltd | Professional & scientific | 2012 |
| Clarendon Square Advisory Limited | Professional & scientific | 2019 |
| Claret Sales and Marketing Ltd | Information & communication | 2020 |
| Claria Ltd | Information & communication | 2015 |
| Clarkco Limited | Agriculture & fishing | 1980 |
| Class a Technologies Ltd | Information & communication | 2014 |
| Classic Cars for Sale Limited | Extraterritorial | 2026 |
| Classic Catering (Midlands) Limited | Hospitality | 2019 |
| Classic Dressage Collection Ltd. | Wholesale & retail | 1999 |
| Classic Equine Ltd | Wholesale & retail | 2025 |
| Classicdressage Ltd | Arts & recreation | 2012 |
| Claverdon Community Shop Limited | Wholesale & retail | 2007 |
| Claverdon Fields Limited | Wholesale & retail | 2012 |
| Claverdon Rugby Club Limited | Arts & recreation | 2014 |
| Claverdon Rugby Clubhouse Limited | Arts & recreation | 2014 |
| Claysmore AS Limited | Information & communication | 2006 |
| Clcf Writing Associates Ltd | Information & communication | 2025 |
| Clean Build Ltd | Administrative & support | 2020 |
| Clear Blue Sky Ltd | Households | 2021 |
| Clearfunds Partners LLP | | 2011 |
| Clearview Agility Ltd | Information & communication | 2026 |
| CLF Commercial Services Limited | Professional & scientific | 2022 |
| Clicck Ltd | Wholesale & retail | 2014 |
| Clifton Delivery Ltd | Information & communication | 2026 |
| Climax Cars Limited | Professional & scientific | 2008 |
| Clive Stanley & Associates Ltd | Professional & scientific | 2025 |
| CLN Traders Limited | Manufacturing | 2017 |
| Clocks in a Nutshell Ltd | Manufacturing | 2024 |
| Cloudgaia Holdings Limited | Financial services | 2021 |
| Cloudgaia Limited | Information & communication | 2017 |
| Cloudhigh Media Ltd | Information & communication | 2014 |
| CLW Change Limited | Information & communication | 2025 |
| Cmlr Holdings Ltd | Financial services | 2024 |
| CMP Quantity Surveying Ltd | Professional & scientific | 2009 |
| Cmwc Construction Limited | Construction | 2025 |
| Co-Op Travel Services Limited | Transport & logistics | 2014 |
| Co-Operative Holidays Limited | Transport & logistics | 2015 |
| Coach Holdings Ltd | Education | 2020 |
| Coaching Moves Limited | Other services | 2015 |
| Coast and Country Cottages Ltd | Real estate | 2021 |
| Cobalt Developments (Alveston) Limited | Construction | 2003 |
| Cocktail Tours UK LLP | | 2018 |
| Coco Rose (UK) Limited | Wholesale & retail | 2007 |
| Coco Rose Limited | Extraterritorial | 2009 |
| Code Black Software Ltd | Information & communication | 2025 |
| Code Ninjas International Franchising Ltd | Administrative & support | 2019 |
| Codebrewer Limited | Information & communication | 2017 |
| Codec Facilities Ltd. | Wholesale & retail | 1979 |
| Cogitate Limited | Professional & scientific | 2007 |
| Colan Limited | Manufacturing | 1981 |
| Colcap (Quartz) LLP | | 2017 |
| Colcap II (Wavendon) Limited | Real estate | 2020 |
| Colcap II LLP | | 2020 |
| Colcap LLP | | 2017 |
| Colemans Office Supplies Limited | Wholesale & retail | 1998 |
| Colhope (Beldray) LLP | | 2023 |
| Colhope (Featherstone) LLP | | 2023 |
| Colhope (Whitehall) LLP | | 2024 |
| Collective Minds Radiology Limited | Information & communication | 2021 |
| Collectors Prints Limited | Extraterritorial | 2004 |
| College Homes Limited | Construction | 1995 |
| College of Medicine and Dentistry Limited | Extraterritorial | 2013 |
| Collektif Limited | Professional & scientific | 2021 |
| Colley Consulting Limited | Professional & scientific | 1999 |