| Causeway Plant Limited | Manufacturing | 2012 |
| Cbelements Ltd | Extraterritorial | 2024 |
| Cbfrequency Ltd | Administrative & support | 2024 |
| CBH International Ltd | Administrative & support | 2025 |
| Cellar One Ltd | Construction | 2019 |
| Cellenor Ltd | Other services | 2018 |
| Celtech Compliancy Solutions Limited | Information & communication | 2025 |
| Celtic Cleaning Company (Pembs) Ltd | Administrative & support | 2023 |
| Celtic Quest Coasteering Limited | Arts & recreation | 2013 |
| Celtic Shellfish Ltd | Agriculture & fishing | 2014 |
| Celtic SMR Limited | Professional & scientific | 1984 |
| Celtic Timber Limited | Administrative & support | 2011 |
| Celtic Tourism Group Limited | Professional & scientific | 2002 |
| Centiloo Ltd | Other services | 2019 |
| Centre 22 Ltd | Administrative & support | 2013 |
| Ceredigion Feel Good Magazine Ltd | Information & communication | 2024 |
| Cerrito Services Ltd | Other services | 2023 |
| CFP Tenby Ltd | Arts & recreation | 2020 |
| CG and JW Properties Ltd | Other services | 2021 |
| CGB 2023 Ltd | Construction | 2020 |
| CH Ventilation & Insulation Ltd | Construction | 2019 |
| Chaleom Ltd | Health & social care | 2025 |
| Champion Chase Limited | Manufacturing | 2017 |
| Channelict Limited | Wholesale & retail | 2024 |
| Chapman Waller Investments Ltd | Real estate | 2023 |
| Character Kitchens & Bathrooms Limited | Wholesale & retail | 2011 |
| Charalampidisn Ltd | Health & social care | 2020 |
| Charis Renovations Ltd | Construction | 2025 |
| Charles Interioras Limited | Wholesale & retail | 2024 |
| Charles Proprietas Limited | Real estate | 2024 |
| Charlymay Vintage Limited | Wholesale & retail | 2024 |
| Check Your Followers CYF | Administrative & support | 2022 |
| Cheesy COW Catering Ltd | Hospitality | 2025 |
| Chenjinhong Ltd | Manufacturing | 2024 |
| Cherry Tree Assets Ltd | Real estate | 2022 |
| Chia Logistics LP | | 2018 |
| Chiswick Lacrosse Limited | Arts & recreation | 2022 |
| Choice Bookkeeping Limited | Professional & scientific | 2017 |
| Chris Hill Tree Services Limited | Administrative & support | 2022 |
| Chris J Enterprises Limited | Hospitality | 2021 |
| Chris Rogers and SON Ltd | Wholesale & retail | 2012 |
| Christina Williams Media Ltd | Information & communication | 2026 |
| CHS International Ltd | Administrative & support | 2025 |
| Churchill Owens Limited | Professional & scientific | 2013 |
| Cinnamon Grove GIN Limited | Other services | 2011 |
| Circle Product Design Limited | Professional & scientific | 2009 |
| City Sparks Electrical Ltd | Construction | 2026 |
| CJL Design & Engineering Limited | Administrative & support | 2008 |
| Claire Carlile Marketing Ltd | Information & communication | 2022 |
| Clajm Future Ltd | Administrative & support | 2022 |
| Clajm Life Ltd | Extraterritorial | 2022 |
| Clarbeston Grange Limited | Agriculture & fishing | 2019 |
| Clark Asset Holdings Ltd | Hospitality | 2016 |
| Clear Betting Academy Ltd | Professional & scientific | 2026 |
| Cleddau Brewing Co. Ltd | Manufacturing | 2025 |
| Cleddau Classic Motorcycles Ltd | Wholesale & retail | 2022 |
| Cleddau Cleaning Limited | Administrative & support | 2013 |
| Cleddau Commercials Ltd | Wholesale & retail | 2025 |
| Cleddau Communications Ltd | Information & communication | 2016 |
| Cleddau Electrical Services Ltd | Construction | 2012 |
| Cleddau Potatoes Limited | Agriculture & fishing | 2024 |
| Clonbarrow Ltd | Real estate | 2025 |
| Clover Park Organics Limited | Extraterritorial | 2001 |
| Cmaine (Shipping) Limited | Administrative & support | 1983 |
| CMS Live Advice Service Ltd | Administrative & support | 2023 |
| Co Create Communication Ltd | Extraterritorial | 2022 |
| Coachange Limited | Professional & scientific | 2003 |
| Coastal Canvas Limited | Manufacturing | 2014 |
| Coastal Cleaning UK & Ireland Limited | Administrative & support | 2020 |
| Coastal Cottages Ltd. | Other services | 1980 |
| Coastal Cottages of Pembrokeshire Limited | Real estate | 1992 |
| Coastland Computers Limited | Other services | 2003 |
| Coastline Cleaning Service Ltd | Administrative & support | 2023 |
| Coastology Limited | Arts & recreation | 2021 |
| Cocreationuk Ltd | Professional & scientific | 2025 |
| COE Stone Ltd | Construction | 2003 |
| Coleman Concepts Ltd | Agriculture & fishing | 2015 |
| Combicrop Limited | Extraterritorial | 2006 |
| Commerce Mews Management Company Limited | Real estate | 2013 |
| Commons Vision Ltd | Professional & scientific | 2008 |
| Compass Construction Tenby Ltd | Construction | 2015 |
| Complete Compliance Ltd | Professional & scientific | 2023 |
| Completion Group Limited | Information & communication | 2025 |
| Comumnet Ltd | Other services | 2024 |
| Conbeer Builders Limited | Construction | 2012 |
| Connecturelations Ltd | Extraterritorial | 2025 |
| Constable Golf Ltd | Wholesale & retail | 2025 |
| Cooking Something (Pembrokeshire) Ltd | Hospitality | 2025 |
| Cool Water Surf Adventure Ltd | Education | 2025 |
| Core of the Poodle Limited | Manufacturing | 2020 |
| Coriander Commercial Limited | Real estate | 2025 |
| Cornish Trade Frames Ltd. | Manufacturing | 2011 |
| Cosmic Dimensions Ltd | Extraterritorial | 2025 |
| Cottleys Developments Ltd | Construction | 2010 |
| Country Living Group Limited | Administrative & support | 2016 |
| Court Vale Developments Limited | Construction | 2000 |
| Craftfix Limited | Construction | 2026 |
| Craigs Dairy Limited | Construction | 1996 |
| CRE8LEARNING Ltd | Professional & scientific | 2016 |
| Creative Riot Ltd | Information & communication | 2017 |