| Corinthian Access Limited | Construction | 2016 |
| Corinthian Homes Block D SPV Limited | Real estate | 2023 |
| Corinthian Homes Group Ltd | Construction | 2019 |
| Corinthian Homes Mulberry House SPV Limited | Real estate | 2023 |
| Corinthian Mulberry House Limited | Construction | 2022 |
| Corner Cairo Limited | Hospitality | 2023 |
| Cornerstone Advocacy Limited | Health & social care | 2025 |
| CORNERSTONE22 Ltd | Hospitality | 2023 |
| Cornerswell Chippy Ltd | Hospitality | 2025 |
| Cornerways Cottage Ltd | Real estate | 2019 |
| Cornstreet Investments Ltd | Real estate | 2013 |
| Corpa Mini Market Ltd | Wholesale & retail | 2020 |
| Corpa Newport Ltd | Hospitality | 2025 |
| Corporate & Personal Recovery Specialists Limited | Professional & scientific | 2007 |
| Corporate Catering Cardiff Limited | Hospitality | 2025 |
| Corporate Event Solutions Ltd | Administrative & support | 2018 |
| Corporation Lounge Ltd | Hospitality | 2018 |
| Corporation Pizza Ltd | Hospitality | 2025 |
| Corpus AI C.I.C. | Information & communication | 2025 |
| Corraine Lewis Property Ltd | Real estate | 2025 |
| Cory Express Limited | Transport & logistics | 2025 |
| Cosmic Touch Ltd | Hospitality | 2015 |
| COSTING360 Limited | Information & communication | 2021 |
| Cosykey Living Limited | Hospitality | 2026 |
| Cotaco Limited | Real estate | 2008 |
| Cotham Hardware Limited | Wholesale & retail | 2020 |
| Cotswold Close (Newport) Company Limited | Households | 2018 |
| Cotswold Court (Management) Company Limited | Households | 1972 |
| Cotswold Group Newport Ltd | Households | 2017 |
| Cotswold Real Estate Management Ltd | Real estate | 2019 |
| Cottage Mews Management Company Limited | Households | 1992 |
| Cotterell Partnership Limited | Professional & scientific | 2007 |
| Cotton and Push Ltd | Wholesale & retail | 2026 |
| Cottonhaus Ltd | Real estate | 2025 |
| Couch & Tree Wellness Limited | Health & social care | 2024 |
| Country Hideouts Ltd | Hospitality | 2022 |
| Country Kids (Castleton) Limited | Health & social care | 2015 |
| Countryside Commercials and Equipment Limited | Administrative & support | 2008 |
| County Cladding Limited | Construction | 2023 |
| County Engineering Limited | Professional & scientific | 2019 |
| County Equestrian Buildings Limited | Manufacturing | 2007 |
| County Equestrian Stables Limited | Extraterritorial | 2018 |
| County Fundraisers Ltd | Wholesale & retail | 2010 |
| County Tyres (Newport, Shropshire) Limited | Wholesale & retail | 1999 |
| Courier 25 Ltd | Transport & logistics | 2018 |
| Courtyard Property Limited | Other services | 2014 |
| Cousinwood Construction Ltd | Construction | 2025 |
| Covey Property Ltd | Real estate | 2013 |
| Covprop Ltd | Real estate | 2019 |
| Cowes Boat Storage Limited | Transport & logistics | 2020 |
| Cowes Fringe Ltd | Arts & recreation | 2022 |
| Cowes Holiday Homes Limited | Hospitality | 2016 |
| Cowes Marine Electrical (UK) Ltd | Professional & scientific | 2013 |
| Cowes Marine Limited | Professional & scientific | 2008 |
| Cowes Movers Limited | Transport & logistics | 2020 |
| Cowes Tanning Limited | Other services | 2025 |
| Cowes Yacht Agency Limited | Wholesale & retail | 2016 |
| COX Electrics Limited | Construction | 2016 |
| COX Family Homes Limited | Real estate | 2017 |
| Coxyco.Com Ltd | Information & communication | 2020 |
| Cozmog Ltd | Wholesale & retail | 2023 |
| Cozy Hutz Ltd | Hospitality | 2026 |
| CP Pizza Ltd | Hospitality | 2019 |
| CP Programming Ltd. | Information & communication | 2020 |
| CPC Pipefitting Ltd | Administrative & support | 2017 |
| CPC Trinity Services Limited | Professional & scientific | 2012 |
| CQC Training Limited | Extraterritorial | 2024 |
| CR (UK) Limited | Other services | 2010 |
| CR Solution Services Ltd | Water & waste | 2025 |
| CR Systems Limited | Information & communication | 2006 |
| CR6 Properties Limited | Real estate | 2016 |
| Crackedminds Limited | Information & communication | 2026 |
| Cradle Ventures Limited | Real estate | 2014 |
| Crafted Locally Limited | Wholesale & retail | 2015 |
| Craftellery UK Limited | Wholesale & retail | 2024 |
| Craig Evans Academy Limited | Professional & scientific | 2026 |
| Craig Evans Content Agency Ltd | Professional & scientific | 2022 |
| Craig Jones Golf Limited | Arts & recreation | 2012 |
| Craigdam Limited | Construction | 1989 |
| Craigdam Services Limited | Professional & scientific | 1983 |
| Cranford Catering Ltd | Hospitality | 2021 |
| Crash OUT Candy Ltd | Wholesale & retail | 2025 |
| Crawley Rigging Ltd | Construction | 2019 |
| Crazy Phones Ltd | Other services | 2017 |
| Crazyfree Limited | Other services | 1995 |
| Create Financial Planning Ltd | Financial services | 2009 |
| Create Wealth Management Ltd | Financial services | 2004 |
| Creating Community Space Co C.I.C. | Other services | 2022 |
| Creation Technology Ltd | Information & communication | 2001 |
| Creative Insomnia Limited | Information & communication | 2010 |
| Credwch Limited | Education | 2019 |
| Creekside Hospitality Limited | Hospitality | 2024 |
| Crepe Takeover Ltd | Hospitality | 2026 |
| Crescent 17 Limited | Professional & scientific | 2016 |
| Crescent Motors (Kerricabs) Limited | Transport & logistics | 2010 |
| Creu Cymru Limited | Arts & recreation | 2004 |
| Crevis Ltd | Financial services | 2022 |
| Crgc Limited | Hospitality | 2024 |
| CRH Repair Ltd | Construction | 2024 |
| Crib Y LAN Residents Limited | Real estate | 2015 |