| Countrywide Employment Services 09 Ltd | Administrative & support | 2021 |
| County Chambers RTM Company Limited | Households | 2023 |
| County Motors Services Limited | Wholesale & retail | 1992 |
| Coup Media Ltd | Information & communication | 2010 |
| Coup the Duke Ltd. | Information & communication | 2024 |
| Coupland Group Ltd | Construction | 2015 |
| Courage to Climb Ltd. | Education | 2023 |
| Courier Express Cotswold Limited | Transport & logistics | 2021 |
| Courier Logistics Nationwide Ltd | Other services | 2019 |
| Coursedge Ltd | Professional & scientific | 2025 |
| Coursehatch Tech Ltd | Wholesale & retail | 2020 |
| Coursetype Limited | Construction | 1999 |
| Court House Rental Properties Limited | Professional & scientific | 2020 |
| Court Rise Management 2020 Limited | Real estate | 2020 |
| Courteous Cleaning Services Limited | Administrative & support | 2013 |
| Courtfield Gardens Studio Limited | Real estate | 2025 |
| Courtfield House Management Limited | Real estate | 1976 |
| Courtiers Limited | Households | 1992 |
| Courtney Soft Ltd | Information & communication | 2026 |
| Courtside Padel Limited | Arts & recreation | 2025 |
| Courtyard Screen Ltd | Administrative & support | 2019 |
| Courtyards Direct Limited | Construction | 2002 |
| Cousins Medical Services Ltd | Information & communication | 2026 |
| Couture Communications Limited | Information & communication | 2017 |
| Cove Capital Ltd | Information & communication | 2026 |
| Cove Developments (Dorset) Ltd | Construction | 2015 |
| Cove Digital Ltd | Information & communication | 2026 |
| Covelo System Limited | Information & communication | 2025 |
| Coven Pictures Limited | Arts & recreation | 2020 |
| Coven Xperience Ltd | Arts & recreation | 2024 |
| Covent Garden London Ltd | Real estate | 2023 |
| Coventry Roofing Group Ltd | Construction | 2026 |
| Coverd Services Ltd | Administrative & support | 2019 |
| Coverness Ltd | Professional & scientific | 2016 |
| Covert Investigations & Surveillance Limited | Administrative & support | 2003 |
| Covid Cleaning & Compliance Limited | Financial services | 2012 |
| Covid Comp Claims Ltd | Administrative & support | 2023 |
| Covid Comp Ltd | Administrative & support | 2023 |
| Covintures Ltd | Manufacturing | 2019 |
| Cowboy Builders Ltd | Construction | 2014 |
| Cowbridge Cabs Limited | Transport & logistics | 2023 |
| Cowbridge Dental Care Limited | Health & social care | 2006 |
| Cowbridge Orthodontics Ltd | Health & social care | 2020 |
| Cowdery & Morris Limited | Financial services | 1983 |
| Cowebb Limited | Information & communication | 2016 |
| Cowley Building Services Limited | Construction | 2016 |
| Cowley Ceilings Ltd | Construction | 2005 |
| Cowley Community Closet CIC | Wholesale & retail | 2024 |
| Cowper Court Management Limited | Households | 1988 |
| Cowshed Communication Limited | Professional & scientific | 2014 |
| Cowy Prime Holiday Lets Ltd | Hospitality | 2026 |
| Cowy Prime Professional Services Ltd | Information & communication | 2026 |
| Cowy Prime Property Management Ltd | Households | 2026 |
| Cowy Prime Property Services Ltd | Construction | 2026 |
| Cowy Prime Real Estates Ltd | Real estate | 2026 |
| COX & Kings Destinations Management Services Limited | Administrative & support | 1997 |
| COX Design and Consult Ltd | Professional & scientific | 2017 |
| COX Plumbing & Heating Ltd | Construction | 2018 |
| Coxon-Link Limited | Administrative & support | 2021 |
| Coyote Coms Limited | Information & communication | 2020 |
| Coyote Ugly Blackpool Ltd | Hospitality | 2024 |
| Coyote Ugly Bristol Ltd | Hospitality | 2023 |
| Coyote Ugly Edinburgh Limited | Hospitality | 2024 |
| Coyote Ugly Liverpool Limited | Hospitality | 2024 |
| Coyote Ugly Nottingham Ltd | Hospitality | 2026 |
| Coyote Ugly Saloon Birmingham Ltd | Hospitality | 2019 |
| Coyote Ugly Saloon Cardiff Ltd | Hospitality | 2019 |
| Coyote Ugly Swansea Ltd | Hospitality | 2024 |
| Cozee Estates Limited | Financial services | 2024 |
| Cozee Management Limited | Real estate | 2023 |
| Cozmic Group Ltd | Administrative & support | 2019 |
| Cozy Commerce Ltd | Wholesale & retail | 2025 |
| Cozy Key Limited | Real estate | 2023 |
| Cozy Koff Ltd | Wholesale & retail | 2025 |
| Cozy Stead Limited | Hospitality | 2025 |
| Cozy Tapas and Grill Limited | Hospitality | 2023 |
| Cozy UK Ltd | Real estate | 2018 |
| Cozymeow Limited | Manufacturing | 2021 |
| Cozystay Management Ltd | Real estate | 2026 |
| CP & KP Properties Limited | Real estate | 2022 |
| CP Electrical Cardiff Ltd | Construction | 2024 |
| CP Financial Group Limited | Professional & scientific | 2025 |
| CP Fresh Produce Supplies Ltd | Wholesale & retail | 2026 |
| CP Maciuc Ltd | Construction | 2019 |
| CP Mental Wellbeing Ltd | Health & social care | 2026 |
| CP Rail Track Land Limited | Construction | 2018 |
| CP Trade International Ltd | Wholesale & retail | 2025 |
| CPA (Cardiff) Limited | Real estate | 2017 |
| CPA Collective Ltd | Manufacturing | 2019 |
| Cpbb Ltd | Real estate | 2023 |
| CPC Services (Cardiff) Limited | Construction | 2026 |
| CPD Precision Ltd | Education | 2025 |
| CPD South Limited | Real estate | 2018 |
| CPE Consulting Ltd | Professional & scientific | 2013 |
| CPI1 Ltd | Professional & scientific | 2019 |
| Cplugin Labs LP | | 2025 |
| CPM Capital Consulting Ltd | Professional & scientific | 2026 |
| CPP Laguna Limited | Hospitality | 2024 |
| Cpphynn Ltd | Information & communication | 2026 |
| CPR Commercial Interiors Ltd | Construction | 2024 |