| Crickhowell Management Company Limited | Households | 2002 |
| Cristal Phoenix Properties Ltd | Real estate | 2026 |
| Cristians Delivery Ltd | Transport & logistics | 2019 |
| Critcare Health Solutions Ltd | Health & social care | 2024 |
| CRL Global Ltd | Transport & logistics | 2025 |
| CRM Services Shropshire Limited | Construction | 2026 |
| Crmd Consulting Ltd | Construction | 2023 |
| Crocker Family Investments Ltd | Real estate | 2023 |
| Crocker Street Tyres and MOT Limited | Wholesale & retail | 2014 |
| Crocus MAR Ltd | Wholesale & retail | 2017 |
| Croft Glazing & Exteriors Limited | Construction | 2021 |
| Croft Meadow Developments Limited | Construction | 2023 |
| Croftwick Limited | Manufacturing | 2012 |
| Croissant Media Ltd | Professional & scientific | 2025 |
| Croll Group Limited | Transport & logistics | 2022 |
| Crome Aviation Limited | Manufacturing | 2026 |
| Cromsshack Limited | Construction | 2015 |
| Crook and Blight Limited | Real estate | 2008 |
| Cross Border Music Group Ltd | Arts & recreation | 2025 |
| Cross Keys Hotel (Newport) Limited | Hospitality | 2016 |
| Cross Keys Waste Management Company Limited | Professional & scientific | 2013 |
| Cross Street Brasserie Ltd | Hospitality | 2022 |
| Cross Street Management Company (Ryde) Limited | Households | 1992 |
| Cross Way Solutions Ltd | Other services | 2017 |
| Cross World Consulting Ltd | Professional & scientific | 2025 |
| Crosscount CXM Limited | Professional & scientific | 2019 |
| Crosskeys Foods Ltd | Hospitality | 2026 |
| Crosskeys Resin Limited | Construction | 2025 |
| Crossman Clark Limited | Arts & recreation | 2003 |
| Crossmark Developments Limited | Professional & scientific | 1989 |
| Crossway International Ltd | Wholesale & retail | 2019 |
| Crow and Jester Limited | Wholesale & retail | 2016 |
| Crow Valley Personal Wealth Management Limited | Financial services | 2013 |
| Crown and Eagle Competitions Ltd | Wholesale & retail | 2026 |
| Crown Garage (Gwent) Limited | Transport & logistics | 1987 |
| Crown Juls Music Ltd | Information & communication | 2025 |
| Crown Trailers Limited | Extraterritorial | 2015 |
| Crownfam Limited | Health & social care | 2025 |
| Crowns Academy Ltd | Other services | 2025 |
| Cruiz Lighting Ltd | Arts & recreation | 2022 |
| Crumlin Spice House Ltd | Hospitality | 2015 |
| Crux Climbing Fitness Ltd | Arts & recreation | 2025 |
| Crwpd Ltd | Professional & scientific | 2014 |
| Cryobaby Ltd | Wholesale & retail | 2025 |
| Crypsiscybertech Ltd | Information & communication | 2025 |
| Crystal Commerce Limited | Wholesale & retail | 2026 |
| Crystal Presentations Limited | Information & communication | 1982 |
| Crystal Solutions Limited | Construction | 1992 |
| Crème DE Cocoa Limited | Hospitality | 2025 |
| Crème DE LA Crème Freelance Nurse Ltd | Professional & scientific | 2025 |
| CS Mentoring and Talks Ltd | Administrative & support | 2023 |
| CS Utility Contractors Limited | Construction | 2013 |
| CS1 Gurnard Limited | Real estate | 2014 |
| CSA Catapult Services Limited | Professional & scientific | 2019 |
| CSA Sports Limited | Professional & scientific | 2018 |
| Csboutique CYF | Wholesale & retail | 2025 |
| Csdl (2021) Holding Limited | Financial services | 2008 |
| Csimba Ltd | Wholesale & retail | 2010 |
| CTF Engineering Ltd | Manufacturing | 2022 |
| Ctflooring Solutions Ltd | Construction | 2026 |
| CTO Marketing Ltd | Administrative & support | 2011 |
| Ctrac Ltd | Professional & scientific | 2024 |
| CTS Couriers Ltd | Transport & logistics | 2022 |
| CU Telecom Ltd | Information & communication | 2018 |
| CUE Presents Ltd | Arts & recreation | 2025 |
| Cultura Care Homes Ltd | Health & social care | 2020 |
| Culture Clash Family Ltd | Professional & scientific | 2024 |
| Culturemindsuk CIC | Health & social care | 2025 |
| Culver Property Limited | Real estate | 1954 |
| Cureo Co Ltd | Wholesale & retail | 2019 |
| Curia Assets Ltd | Real estate | 2021 |
| Curran Services Ltd | Manufacturing | 2025 |
| Current Electrical Engineering Limited | Construction | 2020 |
| Curry Fort Ltd | Administrative & support | 2018 |
| Curtis Bowden & Thomas (Holdings) Limited | Professional & scientific | 2011 |
| Curtis Property Investments Limited | Real estate | 2020 |
| Custom Coach Limited | Wholesale & retail | 2011 |
| Custom Fit Exhausts Limited | Manufacturing | 2002 |
| Custom Leather LAB Ltd | Wholesale & retail | 2025 |
| Custom SIM Engineering Ltd | Manufacturing | 2020 |
| Customised Metalwork Solutions Limited | Manufacturing | 2018 |
| Cutz 51 Ltd | Other services | 2019 |
| CV World Limited | Administrative & support | 2022 |
| CW Electrical Services and Systems Ltd | Construction | 2019 |
| CWB Wholesale Ltd | Wholesale & retail | 2001 |
| CWL Living Ltd | Real estate | 2025 |
| Cwmbran Curtains and Blinds Ltd | Wholesale & retail | 2014 |
| Cwmbran EYE Care Ltd | Wholesale & retail | 2026 |
| Cwmbran Fresh Produce Ltd | Wholesale & retail | 2015 |
| Cwmbran Holdings Ltd | Real estate | 2025 |
| Cwmdowlais Property Limited | Real estate | 2018 |
| Cwmtillery Glass Centre (Holdings) Limited | Extraterritorial | 2012 |
| Cwmtillery Glass Centre Limited | Manufacturing | 2000 |
| Cwrt Perrott Farm Limited | Agriculture & fishing | 2014 |
| Cwrt YR ALA Sports Education CIC | Arts & recreation | 2025 |
| Cwtaylor Ltd | Professional & scientific | 2026 |
| Cwtch Designs Ltd | Professional & scientific | 2019 |
| Cwtch Maintenance Limited | Administrative & support | 2020 |
| Cwtch Pals CIC | Education | 2025 |
| Cwtch Property Group Limited | Real estate | 2018 |