| Cambriani GAS Ltd | Construction | 2019 |
| Cambriani Plumbing & Heating Ltd | Construction | 2021 |
| Cambriani Property Ltd | Real estate | 2022 |
| Cambrica Timber Frames Limited | Construction | 2024 |
| Cambridge Asset Management Group Ltd | Administrative & support | 2019 |
| Cambridge Rare Books Limited | Wholesale & retail | 2015 |
| Camcar IT Limited | Information & communication | 2022 |
| Camcomms Ltd | Information & communication | 2023 |
| Camedee Properties Limited | Real estate | 1976 |
| Cameradan Ltd | Information & communication | 2022 |
| Cameron Nichols Ltd | Transport & logistics | 2025 |
| Cameron Tewson PR Limited | Professional & scientific | 2020 |
| Camilla Elphick Limited | Manufacturing | 2014 |
| Camlais Property Holdings Limited | Real estate | 2019 |
| Cammill Limited | Professional & scientific | 1979 |
| Camnesaf Limited | Health & social care | 2026 |
| Campervans for Hire UK Limited | Administrative & support | 2023 |
| Campingconnect Ltd | Information & communication | 2011 |
| Campion Gardens Care Home Limited | Other services | 2001 |
| Campion Gardens Property LLP | | 2026 |
| Campion Suites LLP | | 2013 |
| Campro Enterprises Limited | Administrative & support | 2006 |
| Cana Nutrition Ltd | Health & social care | 2024 |
| Canaan Properties Ltd | Real estate | 2018 |
| Canal View BUS Cafe Limited | Hospitality | 2018 |
| Cancano Ltd | Administrative & support | 2024 |
| Cancer Information & Support Services | Health & social care | 2009 |
| Cando Connect CIC | Other services | 2021 |
| Cando Hub Ltd | Education | 2025 |
| Candy's Tailoring Ltd | Manufacturing | 2023 |
| Cannaunity Ltd | Administrative & support | 2024 |
| Cannon Heating Services Ltd | Construction | 2007 |
| Cannon Property Services Limited | Real estate | 2026 |
| Canolfan Gofal Plant Tiddlywinks Childcare Centre Cyfyngedig | Health & social care | 1995 |
| Canolfan Ltd. | Hospitality | 2005 |
| Canprint Limited | Manufacturing | 2011 |
| Cansense Laboratories Ltd | Professional & scientific | 2024 |
| Cansense Ltd | Professional & scientific | 2018 |
| Cantellow Groundworks Limited | Agriculture & fishing | 2018 |
| Cantellow Tree Surgery Ltd | Agriculture & fishing | 2018 |
| Canter Creations Ltd | Financial services | 2025 |
| Canulet 2015 Limited | Wholesale & retail | 2015 |
| Capabiliteez Ltd | Information & communication | 2011 |
| Capacity Resolve Limited | Public administration | 2023 |
| Capel Construction Ltd | Construction | 2025 |
| Capel Property Services Ltd | Construction | 2023 |
| Capital 2020 Ltd | Construction | 2014 |
| Capstone Academy Ltd | Education | 2024 |
| Captain John Gordon Marine Survey Limited | Professional & scientific | 2001 |
| Capybaracards Ltd | Wholesale & retail | 2025 |
| Car Go Swansea Limited | Transport & logistics | 2024 |
| Car Hire (Day of Swansea) Limited | Administrative & support | 1956 |
| Car Motive Limited | Wholesale & retail | 2018 |
| Car-Tech (South Wales) Limited | Wholesale & retail | 2012 |
| Caradog Landscapes Limited | Construction | 2016 |
| Caravan Team Limited | Professional & scientific | 2008 |
| Card Show Events Ltd | Administrative & support | 2025 |
| Cardamon Curry Ltd | Hospitality | 2025 |
| Cardi Consulting Ltd | Administrative & support | 2023 |
| Cardiac Insight Limited | Extraterritorial | 2014 |
| Cardiff Montessori School Limited | Education | 2016 |
| Cardiff Period Developments Limited | Extraterritorial | 2006 |
| Cardiff Renovations Limited | Information & communication | 2002 |
| Cardiff Rheumatology Services Limited | Health & social care | 2018 |
| Cardifference Ltd | Health & social care | 2026 |
| Cardy Investments Limited | Financial services | 2025 |
| Care & Repair Solutions Ltd | Construction | 2011 |
| Care 4 YOU Proffessionals Ltd | Health & social care | 2014 |
| Care and Repair Western Bay | Health & social care | 2017 |
| Care by Morris Ltd | Financial services | 2024 |
| Care Centres Wales Limited | Health & social care | 1998 |
| Care Estates Limited | Real estate | 2022 |
| Care Haven Solutions Ltd | Administrative & support | 2025 |
| Care Unity Limited | Health & social care | 2020 |
| Care&Co Ltd | Health & social care | 2021 |
| Carelytic Ltd | Professional & scientific | 2025 |
| Carenza Consultancy Ltd | Professional & scientific | 2025 |
| Carers Creative CIC | Education | 2021 |
| Cargoattend Limited | Administrative & support | 1995 |
| Cari Aromas & Gifts Ltd | Wholesale & retail | 2025 |
| Cariad Bridal Limited | Wholesale & retail | 2005 |
| Cariad Cafe Limited | Hospitality | 2023 |
| Cariad Consultancy and Management Ltd | Professional & scientific | 2024 |
| Cariad Counselling & Supervision Limited | Health & social care | 2026 |
| Cariad Medical Limited | Health & social care | 2019 |
| Cariad Mortgage Solutions Ltd | Financial services | 2023 |
| Carina UK Holdco Ltd. | Information & communication | 2016 |
| Caring Hands 4U Ltd | Health & social care | 2025 |
| Caring Hands Homecare South Wales Limited | Health & social care | 2016 |
| Cariri Ltd | Information & communication | 2023 |
| Carisma Villas Limited | Real estate | 2006 |
| Carl Atkinson Media Ltd | Information & communication | 2025 |
| Carlam Ltd | Information & communication | 2017 |
| Carlino Hospitality Ltd | Hospitality | 2018 |
| Carlisle Communications Ltd | Administrative & support | 2019 |
| Carlisle Holding (Group) Limited | Real estate | 2016 |
| Carl’S Carpentry & Maintenance Service Ltd | Manufacturing | 2020 |
| Carman Developments Limited | Real estate | 2018 |
| Carmarthen Assets Limited | Real estate | 2020 |
| Carmarthen Road Business Park Limited | Real estate | 2021 |