| Clearly Better Cleaning Ltd | Administrative & support | 2024 |
| Clearway Removals and Clearances Ltd | Transport & logistics | 2026 |
| Clementine Studio Ltd | Professional & scientific | 2021 |
| Click Happens Limited | Other services | 2015 |
| Clicks Services Limited | Construction | 2022 |
| Clifton Wood Estates Limited | Construction | 1981 |
| Clifty Employee Ownership Trustee Limited | Professional & scientific | 2024 |
| Clinica DE Datos Limited | Information & communication | 2010 |
| Clinique DE Donnees Limited | Information & communication | 2008 |
| Clippaz Ltd | Other services | 2015 |
| Clonestrand Ltd | Construction | 2024 |
| Close Solutions Limited | Education | 2019 |
| Clover Carers Ltd | Health & social care | 2014 |
| CLR Lifestyles Ltd | Administrative & support | 2021 |
| CLT Bathrooms & Kitchens Limited | Construction | 2024 |
| CLT Properties (Bridgend) Limited | Real estate | 2020 |
| Club Penybont Limited | Arts & recreation | 2013 |
| Clwb Rygbi Pen-Y-Bont AR Ogwr Limited | Arts & recreation | 2018 |
| CM Betts Properties Ltd | Real estate | 2024 |
| CMJ Performance Limited | Wholesale & retail | 2024 |
| CML Brands Limited | Wholesale & retail | 2026 |
| CMU Holdings 2014 Limited | Administrative & support | 2014 |
| CMU Infrastructure Limited | Construction | 2014 |
| CMU Management Limited | Administrative & support | 2014 |
| CN Bricklaying Ltd | Construction | 2023 |
| Coach House Collective Ltd | Arts & recreation | 2020 |
| Coached by Luke and Beth Ltd | Other services | 2023 |
| Coast 2 Coast Building Control Limited | Professional & scientific | 2010 |
| Coast 2 Coast Holdings Ltd | Financial services | 2022 |
| Coast Beauty Ltd | Administrative & support | 2016 |
| Coast Competitions Ltd | Wholesale & retail | 2026 |
| Coastal OIL and GAS Limited | Mining & quarrying | 1997 |
| Coastal Staycations Ltd | Real estate | 2021 |
| Cobbles Kitchen Limited | Hospitality | 2016 |
| Coco Cheveux Ltd | Other services | 2013 |
| Code Ninjas Wales Limited | Education | 2021 |
| Codel Software Ltd | Information & communication | 2006 |
| Coed Parc Management Limited | Real estate | 2020 |
| Coed-Y-Mwstwr Golf Club (1998) Limited | Arts & recreation | 1998 |
| Coedcae Property Services Ltd | Real estate | 2021 |
| COFFEE@12 Ltd | Hospitality | 2022 |
| Coffeepro Limited | Wholesale & retail | 2008 |
| Coffi Catering Limited | | 2012 |
| Cofio Dementia Training Limited | Professional & scientific | 2014 |
| Cofus CYF | Administrative & support | 2014 |
| Cognios Limited | Information & communication | 2016 |
| Cognition International Ltd | Health & social care | 2022 |
| Coin Clear Limited | Information & communication | 2019 |
| Coingenia Limited | Professional & scientific | 2018 |
| Coity Coast + Country Ltd | Hospitality | 2022 |
| Coity Consulting Limited | Professional & scientific | 2011 |
| Coity Croft Limited | Construction | 2022 |
| Coity Engineering and Site Services Ltd | Manufacturing | 2010 |
| Coity Ltd | Hospitality | 2016 |
| Coity Van Sales Ltd | Wholesale & retail | 2024 |
| Cold Black Label Limited | Wholesale & retail | 2010 |
| Colega Consulting Ltd | Education | 2014 |
| Colin Stevens Ltd | Information & communication | 2008 |
| Collectmywheels.Com Limited | Administrative & support | 2008 |
| Colliers Arms Limited | Extraterritorial | 2018 |
| Collies Property Ltd | Real estate | 2022 |
| Columbus Developments Limited | Real estate | 2024 |
| Comclean LLP | | 2022 |
| Comercity Ltd | Professional & scientific | 2025 |
| Comfort Crew Home Care Ltd | Health & social care | 2025 |
| Comgem Limited | Information & communication | 2005 |
| Commercial Print Wales Ltd | Manufacturing | 2012 |
| Community Active Travel Limited | Transport & logistics | 2020 |
| Community Drop and Shop CIC | Wholesale & retail | 2023 |
| Community Futures Wales Ltd | Arts & recreation | 2009 |
| Compass Residential & Commercial Ltd | Real estate | 2025 |
| Compassionate Film 1 Ltd | Information & communication | 2017 |
| Complete Accounting and Business Services Ltd | Professional & scientific | 2019 |
| Complete Care Plus Limited | Health & social care | 2016 |
| Complete Fine Turf Solutions Limited | Professional & scientific | 2021 |
| Complete Remedial Solutions (CRS) Ltd | Other services | 2018 |
| Component Hardware Solutions Ltd | Wholesale & retail | 2023 |
| Comprehensive Solutions Limited | Information & communication | 1997 |
| Compton House Practice Ltd | Health & social care | 2016 |
| Comva Ltd | Wholesale & retail | 2023 |
| Concrete Business Ltd. | Manufacturing | 2006 |
| Connexa Properties Ltd | Real estate | 2025 |
| Consolidated Tools International Limited | Wholesale & retail | 1984 |
| Construction Bros Ltd | Construction | 2025 |
| Construction Skills Training Limited | Education | 2002 |
| Consulere Consulting Ltd | Administrative & support | 2017 |
| Container Sales South Wales Ltd | Extraterritorial | 2020 |
| Contractor Support Services Limited | Construction | 2018 |
| Control 2K Limited | Information & communication | 1999 |
| Control and Service Technology Limited | Construction | 2003 |
| Coolace Limited | Hospitality | 2018 |
| Cooleasy Ltd | Wholesale & retail | 2020 |
| Copia Ltd | Professional & scientific | 2024 |
| Copperhouse Studios Ltd | Information & communication | 2025 |
| Coppice Alupack Limited | Manufacturing | 1972 |
| Cornelius Design to Print Limited | Manufacturing | 2001 |
| Cornelly Barber Ltd | Other services | 2025 |
| Cornelly Development Trust | Administrative & support | 2005 |
| Cornerstone (Bridgend) Limited | Households | 1986 |
| Cornerstone Construction (Bridgend) Limited | Construction | 1989 |