| CCF (UK) Limited | Manufacturing | 2011 |
| CCF Hydraulics Ltd | Manufacturing | 2009 |
| Ccpm (IW) Limited | Real estate | 2008 |
| Ccpy Limited | Administrative & support | 2016 |
| CD Motors Ltd | Wholesale & retail | 2020 |
| CDB Holdings UK Limited | Wholesale & retail | 2022 |
| CDF Marine Services Ltd | Manufacturing | 2026 |
| CDH Engineering Design Limited | Professional & scientific | 2025 |
| CDO Project Management Limited | Professional & scientific | 2019 |
| CDP Decorating Contractors Limited | Administrative & support | 2018 |
| CDP Subsea Ltd | Information & communication | 2015 |
| Cdrpropertymaintenance Ltd | Administrative & support | 2025 |
| CE Image Holdings Limited | Financial services | 2018 |
| CE Image Limited | Other services | 2016 |
| CE Image Property Limited | Real estate | 2018 |
| CE Safety Solutions Ltd | Professional & scientific | 2008 |
| CEB Home Invest Ltd | Real estate | 2025 |
| CEB Rent Solutions Limited | Real estate | 2025 |
| CEC Property Investments Limited | Real estate | 2019 |
| Cedar & Marmor Limited | Construction | 2025 |
| Cedar & Marmor Lodgings Limited | Real estate | 2025 |
| Cedar Energy Limited | Energy | 2009 |
| Cedarbrook Services Ltd | Administrative & support | 2024 |
| Cedric John & Sons Limited | Wholesale & retail | 2001 |
| Cedric John Logistics Limited | Extraterritorial | 2013 |
| Ceekay Solutions Limited | Health & social care | 2023 |
| CEF Construction Ltd | Construction | 2017 |
| Celdra Tech Solutions Limited | Information & communication | 2020 |
| Celestial Haven Limited | Other services | 2023 |
| Celf Caerleon Arts CIC | Arts & recreation | 2013 |
| Celine Eleonore Ltd | Transport & logistics | 2025 |
| Cellar Wizard Ltd | Administrative & support | 2026 |
| Cellco (FRS) Ltd | Construction | 2011 |
| Celtic Antiques Limited | Wholesale & retail | 2025 |
| Celtic Aviation LLP | | 2023 |
| Celtic Cross Community People (Cccp) L.P. | | 2000 |
| Celtic Cross Community Property (Cccp) L.P. | | 2007 |
| Celtic Cross Consultancy Projects (Cccp) L.P. | | 2000 |
| Celtic Cross Fit LLP | | 2010 |
| Celtic Developments (Pontcanna) Limited | Construction | 2013 |
| Celtic Fuel Oils Limited | Wholesale & retail | 2020 |
| Celtic Hotel Developments Limited | Other services | 2014 |
| Celtic House Investment Partners Limited | Financial services | 1994 |
| Celtic Kilncare Limited | Manufacturing | 1992 |
| Celtic Leisure Logistics Ltd | Construction | 2025 |
| Celtic Manor Service Company Limited | Professional & scientific | 2017 |
| Celtic Sandwiches Limited | Hospitality | 2019 |
| Celtic Software Limited | Information & communication | 2018 |
| Celtic Solutions Wales Limited | Transport & logistics | 2002 |
| Celtic Spas Distribution Limited | Wholesale & retail | 2021 |
| Celtic Travel Services Ltd | Administrative & support | 2010 |
| Celtica Studio Ltd | Administrative & support | 2020 |
| Celtlec Electrical Ltd | Manufacturing | 2023 |
| Celynen Collieries Institute and Memorial Hall Limited | Arts & recreation | 2010 |
| Celynen Consulting Limited | Professional & scientific | 2024 |
| Centra Advisory & Projects Ltd | Professional & scientific | 2026 |
| Central Garage (Essex) Limited | Administrative & support | 2008 |
| Central Garage (Newport) Limited | Wholesale & retail | 1970 |
| Central Heating Services (UK) Limited | Construction | 2006 |
| Central Redevelopment Limited | Real estate | 1995 |
| Central Taxis Ltd | Transport & logistics | 2025 |
| Centre 1184 Ltd | Arts & recreation | 2023 |
| Centre for Global Advancement CIC | Professional & scientific | 2020 |
| Ceramic Substrates & Components Limited | Manufacturing | 1968 |
| Ceri Edwards Limited | Education | 2017 |
| Cernunnos Developments Limited | Real estate | 2016 |
| Certainly Secure Limited | Other services | 2019 |
| Certezza Consulting Services Limited | Professional & scientific | 2016 |
| Certus Transport Ltd | Transport & logistics | 2014 |
| Ceryscakes Ltd | Wholesale & retail | 2025 |
| Cerysthomas CYF | Wholesale & retail | 2025 |
| CES (IOW) Ltd | Wholesale & retail | 2025 |
| CEY Homes Ltd | Real estate | 2025 |
| CF64 PO Ltd | Wholesale & retail | 2026 |
| CFM Cardiac Care Ltd | Health & social care | 2016 |
| Cfpm Limited | Information & communication | 2009 |
| CG Construction (SW) Limited | Construction | 2022 |
| CGE Properties Limited | Real estate | 2020 |
| CGS Construction Crosskeys Limited | Construction | 2019 |
| CH Property IOW Ltd | Real estate | 2024 |
| CH13 Promotions Limited | Arts & recreation | 2020 |
| CH45 Images Ltd | Arts & recreation | 2023 |
| Chacho Courier Limited | Transport & logistics | 2022 |
| Chago Retail Ltd | Wholesale & retail | 2020 |
| Chai Logs Ltd | Hospitality | 2024 |
| Chaiiwala Food Bristol 2 Ltd | Hospitality | 2026 |
| Chain Free Agency Limited | Real estate | 2022 |
| Chale Show Limited | Arts & recreation | 2008 |
| Challenge Precision Engineering Limited | Professional & scientific | 2021 |
| Challenging Boundaries Consultancy Ltd | Professional & scientific | 2012 |
| Chambers Legal Services Limited | Professional & scientific | 2019 |
| Channel Auto Services Ltd | Wholesale & retail | 2026 |
| Channing Electrical Ltd | Construction | 2020 |
| Chapel Court (Newport) Management Company Limited | Households | 2007 |
| Chapelwood Estate Planning Limited | Financial services | 2003 |
| Chapelwood Financial Planning Limited | Financial services | 2001 |
| Chappell Tyre Services (Glamorgan) Limited | Professional & scientific | 1983 |
| Chappz Ltd | Wholesale & retail | 2019 |
| Chapter 40 Recruitment Ltd | Administrative & support | 2024 |
| Charal Auto Parts Ltd | Wholesale & retail | 2020 |