| Commercial Property Consultancy Limited | Administrative & support | 2024 |
| Commercial Rent Bailiffs Limited | Other services | 2012 |
| Commercial Safety Supplies Ltd | Wholesale & retail | 2020 |
| Commercial Street 1975 Limited | Extraterritorial | 2015 |
| Commercial Street Foods Ltd | Wholesale & retail | 2019 |
| Commercial Surveying Hereford Ltd | Professional & scientific | 2010 |
| Commerly Ltd | Professional & scientific | 2023 |
| Commfix Limited | Construction | 2008 |
| Commission Reduction Ltd | Financial services | 2019 |
| Commissioning Services (South East) Limited | Water & waste | 2019 |
| Commix Hub Ltd | Wholesale & retail | 2025 |
| Commodex UK Ltd | Wholesale & retail | 2025 |
| Common FIG Limited | Agriculture & fishing | 2021 |
| Common Flame Software Limited | Information & communication | 2025 |
| Common Good Store Ltd | Wholesale & retail | 2021 |
| Common Ground Advisory Ltd | Professional & scientific | 2026 |
| Common Matter Limited | Information & communication | 2025 |
| Common Sense Campaign Limited | Information & communication | 2025 |
| Commonside Assets Ltd | Financial services | 2025 |
| Commonwealth Exchange Holding Ltd | Wholesale & retail | 2022 |
| Commonwealth Foundation | Financial services | 2021 |
| Comms Solve Limited | Information & communication | 2010 |
| Commstream Ltd | Information & communication | 2025 |
| Communal Limited | Professional & scientific | 2015 |
| Communect Limited | Professional & scientific | 2024 |
| Communicate Advisors Ltd | Professional & scientific | 2018 |
| Communicatics Ltd | Information & communication | 2026 |
| Communication Activities and Services Global Group Ltd | Financial services | 2024 |
| Communication Crossroads Limited | Information & communication | 2016 |
| Communique 24/7 Limited | Arts & recreation | 2007 |
| Community Advertise Ltd | Information & communication | 2021 |
| Community Cooperation Wales CIC | Professional & scientific | 2022 |
| Community Draws Limited | Information & communication | 2024 |
| Community Energy Wales - Ynni Cymunedol Cymru | Other services | 2012 |
| Community Healthcare Services Ltd | Health & social care | 2019 |
| Community Honeycomb CIC | Wholesale & retail | 2023 |
| Community Housing Cymru | Other services | 1989 |
| Community Housing Cymru - Policy and Research Limited | Administrative & support | 2009 |
| Community Murals CIC | Arts & recreation | 2022 |
| Community Projects Concepts Ltd | Administrative & support | 2014 |
| Community Property Services Ltd | Real estate | 2024 |
| Community Utilities Ltd | Professional & scientific | 2018 |
| Community Welcome Spots CIC | Other services | 2026 |
| Communiverse Ltd | Professional & scientific | 2024 |
| Comnexis Ltd | Wholesale & retail | 2020 |
| Comnext Ltd | Wholesale & retail | 2025 |
| Comp Management Limited | Professional & scientific | 1992 |
| Compact Power Systems Ltd | Wholesale & retail | 2020 |
| Companies Bureau Limited | Administrative & support | 2024 |
| Company Check Ltd | Information & communication | 2003 |
| Company Holder | Extraterritorial | 2023 |
| Company Lupus Tech Ltd | Information & communication | 2024 |
| Company of Sirens Theatre Company Limited | Arts & recreation | 2015 |
| Company Revive Ltd | Information & communication | 2025 |
| Company Secretary (Nominees) Limited | Professional & scientific | 1992 |
| Compare Aesthetics Ltd | Information & communication | 2025 |
| Compare Airport Parking Services Limited | Transport & logistics | 2026 |
| Compare Home Improvements Ltd | Other services | 2019 |
| Compare My Move Limited | Transport & logistics | 2012 |
| Compare Private Care Limited | Professional & scientific | 2014 |
| Compass Commerce Limited | Financial services | 2018 |
| Compass Compassion Ltd | Wholesale & retail | 2026 |
| Compass Ethnic Limited | Wholesale & retail | 2025 |
| Compass GT Limited | Wholesale & retail | 2020 |
| Compass North Holdings Limited | Manufacturing | 2021 |
| Compassionate Mental Health CIC | Information & communication | 2019 |
| Compensation Advice Accident Support Ltd | Financial services | 2017 |
| Competify Limited | Wholesale & retail | 2025 |
| Competitive Leisure Limited | Professional & scientific | 2021 |
| Competo Consult Ltd | Administrative & support | 2024 |
| Compi Trade PC | | 2014 |
| Compinfy Ltd | Other services | 2025 |
| Compleo Superyachts Limited | Financial services | 2020 |
| Complete Associates Limited | Information & communication | 2007 |
| Complete Bathrooms Tyneside Limited | Wholesale & retail | 2011 |
| Complete Building, Plastering and Decorating Services Ltd | Construction | 2016 |
| Complete Claims Ltd | Financial services | 2019 |
| Complete Cleaning Specialists Ltd | Other services | 2020 |
| Complete Corporation Limited | Other services | 2019 |
| Complete Earth Limited | Extraterritorial | 2013 |
| Complete Electric Services Ltd | Construction | 2018 |
| Complete Group Build Ltd | Construction | 2021 |
| Complete Installation Services Ltd | Other services | 2016 |
| Complete Landscaping Solutions Limited | Administrative & support | 2017 |
| Complete Monitoring and Maintenance Ltd | Administrative & support | 2019 |
| Complete Power Ltd | Administrative & support | 2019 |
| Complete Solution Property Group Ltd | Construction | 2019 |
| Complete Trade Limited | Wholesale & retail | 2015 |
| Complex Capital Limited | Financial services | 2022 |
| Complexwales Ltd | Professional & scientific | 2021 |
| Compliance Electrical Ltd | Construction | 2024 |
| Compliance Guard Ltd | Real estate | 2026 |
| Compliance PAL Limited | Financial services | 2021 |
| Complications Guru Ltd | Health & social care | 2025 |
| Comply.Ai Ltd | Administrative & support | 2025 |
| Composed Edits Limited | Administrative & support | 1998 |
| Composeum Limited | Information & communication | 2023 |
| Composite Craftwork Ltd | Manufacturing | 2019 |
| Composite Inspection Limited | Professional & scientific | 2006 |
| Compostela Limited | Wholesale & retail | 2005 |