| Caerwill Financial Planning Ltd | Professional & scientific | 2022 |
| Caesars Investments Ltd | Professional & scientific | 2025 |
| Caesium Developments Limited | Construction | 2019 |
| Cafali Ltd | Wholesale & retail | 2024 |
| Cafe 37 Cardiff Ltd | Hospitality | 2022 |
| Cafe Artiste Limited | Hospitality | 2022 |
| Cafe DU Chat Noir Cardiff Limited | Hospitality | 2024 |
| Cafe DU Chat Noir Limited | Hospitality | 2015 |
| Cafe Mellon Ltd | Hospitality | 2014 |
| Cafe Pep's Ltd | Hospitality | 2023 |
| Cafe Tree Limited | Hospitality | 2023 |
| CAFE33A Limited | Hospitality | 2019 |
| Caffe Basch Limited | Manufacturing | 2020 |
| Caffeine & Krooks Ltd | Wholesale & retail | 2022 |
| Caffeine Marketing Ltd | Professional & scientific | 2011 |
| Caflo Ltd | Wholesale & retail | 2025 |
| Cafross Recruits Ltd | Administrative & support | 2021 |
| CAG Electrical Ltd | Construction | 2020 |
| Cahayes Consultants Limited | Information & communication | 2017 |
| Caires Care Ltd | Health & social care | 2013 |
| Cairn Bexley Ltd | Wholesale & retail | 2025 |
| Cairngroup Advisory Ltd | Professional & scientific | 2022 |
| Caishen Capital Limited | Construction | 2019 |
| Caitlin Davies Ltd | Real estate | 2023 |
| Caitong Limited | Wholesale & retail | 2023 |
| Caiusent Ltd | Wholesale & retail | 2025 |
| Caixa 8 Savings & Loan Ltd | Financial services | 2021 |
| CAJ Web Services Limited | Information & communication | 2008 |
| CAK & Sons Limited | Construction | 2018 |
| Cake Delusions BDS Limited | Manufacturing | 2015 |
| Cake That Limited | Manufacturing | 2026 |
| Cakeforyou Limited | Hospitality | 2025 |
| Cakir Software Limited | Information & communication | 2025 |
| Cakli Foods Limited | Hospitality | 2016 |
| CAL Properties Limited | Real estate | 2012 |
| Cala Pharma Limited | Professional & scientific | 2015 |
| Calan Retail Limited | Real estate | 2006 |
| Calapod Trading Limited | Other services | 2018 |
| Calati Performance Limited | Arts & recreation | 2019 |
| Calcam Properties Ltd | Real estate | 2025 |
| Calchemyt Ltd | Information & communication | 2023 |
| Calcspar Limited | Professional & scientific | 2016 |
| Caldicot Hand Car Wash Ltd | Administrative & support | 2024 |
| Cale Power Limited | Energy | 2008 |
| Calebjosh Computers Ltd | Other services | 2022 |
| Caledon Business Services Limited | Administrative & support | 2008 |
| Caledonian Installs Ltd | Construction | 2011 |
| Cali Tacos Ltd | Hospitality | 2020 |
| Calibre - Centre for People Development Ltd | Education | 2015 |
| Calibre Communications Limited | | 1990 |
| Calibre Plumbing Ltd | Construction | 2025 |
| Calica Properties Ltd | Real estate | 2017 |
| Califive Properties Ltd | Real estate | 2022 |
| California Communications & Entertainment Company Limited | Manufacturing | 2011 |
| California Ventures Limited | Wholesale & retail | 2020 |
| Calista Group Ltd | Financial services | 2021 |
| CALL2FIX Ltd | Construction | 2016 |
| Callaghan Electrical Limited | Construction | 2014 |
| Callair AI Ltd | Information & communication | 2025 |
| Callpad Limited | Administrative & support | 2025 |
| Callum Ashley Ltd | Wholesale & retail | 2025 |
| Calm Investments (Cardiff) Ltd | Real estate | 2016 |
| Calmera Ltd | Information & communication | 2025 |
| Calmworks Studio Limited | Manufacturing | 2025 |
| Calmy Limited | | 2009 |
| Calon Beauty Ltd | Other services | 2024 |
| Calon Catering Services Ltd | Hospitality | 2012 |
| Calon in the Community Ltd | Other services | 2023 |
| Calon Infrastructure Limited | Professional & scientific | 2026 |
| Calon Limited | Professional & scientific | 2026 |
| Calon Rhiwbeina Ltd | Wholesale & retail | 2014 |
| Calstone Limited | Real estate | 2017 |
| Calum Barber Limited | Wholesale & retail | 2025 |
| Calverton Mobile Mechanic Limited | Professional & scientific | 2026 |
| Calvin Group Limited | Wholesale & retail | 2023 |
| Calvio Limited | Wholesale & retail | 2025 |
| Calypso Sounds Ltd | Information & communication | 2024 |
| Calypso Studios (Old Company) LLP | | 2022 |
| Calzaghe Mini Dragons Limited | Education | 2019 |
| CAM 2 Limited | Real estate | 2020 |
| CAM Engineering Fabrication (Pyle) Limited | Manufacturing | 2002 |
| Cama Consulting Ltd | Information & communication | 2025 |
| Camara DE Emprendimiento, Comercio E Inversion DE Latinoamericanos EN Europa Limited | Professional & scientific | 2019 |
| Camarilla Media Limited | Professional & scientific | 2017 |
| Cambay AI Nexus Ltd | Administrative & support | 2025 |
| Cambent Ltd. | Information & communication | 2016 |
| Cambi Electrical Limited | Construction | 2025 |
| Cambrensis Communications Limited | Arts & recreation | 1989 |
| Cambria Digital Services Limited | Information & communication | 2026 |
| Cambria Events Crew Ltd | Arts & recreation | 2023 |
| Cambria Maintenance Services Limited | Administrative & support | 2010 |
| Cambria Property Ltd | Real estate | 2019 |
| Cambrian Alliance Limited | Administrative & support | 2000 |
| Cambrian Asset Management LLP | | 2008 |
| Cambrian Assets Limited | Real estate | 2024 |
| Cambrian Carbon Limited | Mining & quarrying | 2025 |
| Cambrian Cloud Ltd | Information & communication | 2021 |
| Cambrian Connect Limited | Information & communication | 2020 |
| Cambrian Construction Equipment Limited | Manufacturing | 1974 |
| Cambrian Dragon Investments Limited | Financial services | 1964 |