| Clyde Holdings Ltd | Professional & scientific | 2018 |
| Clyde Pneumatic Conveying Ltd | Manufacturing | 1994 |
| Clyde Sturtevant Limited | Extraterritorial | 1899 |
| CM Alloys Investments Ltd | Real estate | 2025 |
| CM Alloys Ltd | Professional & scientific | 2023 |
| CM Engineering Solutions Ltd | Administrative & support | 2019 |
| CM Mechanical Services Ltd. | Manufacturing | 2011 |
| CM Transport 12 Limited | Transport & logistics | 2019 |
| CM UK Property Limited | Real estate | 2019 |
| Cm&Son Movements Ltd | Transport & logistics | 2025 |
| CMA Comms Ltd | Information & communication | 2015 |
| CMA Investment Group Limited | Real estate | 2024 |
| CMC Holdings 2026 Ltd | Financial services | 2026 |
| CMD Electrical Engineering Limited | Construction | 2021 |
| CMD Vehicle Accident Repair Centre Ltd | Construction | 2023 |
| CMH Mechanical Limited | Construction | 2010 |
| CML (North) Limited | Administrative & support | 2024 |
| Cmms Transport and Site Services Ltd | Wholesale & retail | 2025 |
| CMP 85 Limited | Transport & logistics | 2020 |
| CMP Estates Ltd | Financial services | 2026 |
| Cmpc Ltd | Health & social care | 2026 |
| Cmquo Ltd | Professional & scientific | 2013 |
| CMS Transport Ltd | Transport & logistics | 2025 |
| CMT Global Ltd | Administrative & support | 2019 |
| CMT Property Maintenance Ltd | Construction | 2026 |
| Cmvs Holdings Limited | Wholesale & retail | 2025 |
| CMW Business and Accounting Solutions Limited | Professional & scientific | 2013 |
| CN Bars Ltd | Hospitality | 2026 |
| CNA Logistics Ltd | Transport & logistics | 2024 |
| CNA Trans Ltd | Transport & logistics | 2016 |
| CNA Transport Limited | Transport & logistics | 2019 |
| CNB International Ltd | Other services | 2023 |
| Cnlee Properties Ltd | Real estate | 2021 |
| CNS Physiotherapy Limited | Health & social care | 2022 |
| Co Site Services Ltd | Construction | 2018 |
| Co Vatavu Ltd | Transport & logistics | 2022 |
| Co&Rona Ltd | Transport & logistics | 2021 |
| Co.M.B Trading Ltd | Construction | 2024 |
| Coach B Athletic Development Ltd | Education | 2023 |
| Coach for Growth Consultant Services Limited | Professional & scientific | 2016 |
| Coaching for Change Ltd | Professional & scientific | 2006 |
| Coast & Counties Contractors Limited | Construction | 2003 |
| Coastbrand Limited | Extraterritorial | 2012 |
| Coastline Vehicle Delivery Ltd | Transport & logistics | 2020 |
| Coaststrike Limited | Extraterritorial | 2012 |
| Coates & Co UK Limited | Financial services | 2017 |
| Cobalt Peak Creative Ltd | Extraterritorial | 2025 |
| Cobas Limited | Professional & scientific | 2009 |
| Cobble Transport Ltd | Transport & logistics | 2017 |
| Cobrief Limited | Information & communication | 2023 |
| Coco's Home Stays Ltd | Extraterritorial | 2024 |
| Coco's Mobile Valeting Ltd | Wholesale & retail | 2022 |
| Coconut Tiger Ltd | Professional & scientific | 2025 |
| Cocoon & Bloom Ltd | Manufacturing | 2025 |
| Cocoon by Lillz Reeh Ltd | Wholesale & retail | 2023 |
| Code Laboratory Ltd | Information & communication | 2020 |
| Codes Koala Ltd | Extraterritorial | 2025 |
| Codescope Ltd | Information & communication | 2025 |
| Codex Global Limited | Professional & scientific | 2002 |
| Codex Holdings Limited | Real estate | 2008 |
| Codex Print Limited | Manufacturing | 2011 |
| Codex Translate Limited | Professional & scientific | 2011 |
| Codfather Harworth Ltd | Hospitality | 2025 |
| Codie's Counselling Ltd | Public administration | 2025 |
| Codive Ltd | Information & communication | 2026 |
| Coen Construction Limited | Real estate | 2011 |
| Coffee Creative Limited | Administrative & support | 2007 |
| Coffee House Newark Ltd | Hospitality | 2016 |
| Coffee Machine Services Limited | Other services | 2009 |
| Cog'O'Two Limited | Manufacturing | 2013 |
| Cohesive Technology Limited | Information & communication | 2016 |
| Coin Furniture Limited | Wholesale & retail | 2013 |
| Cojocaru Speciation Ltd | Transport & logistics | 2016 |
| Colbro Construction Company Limited | Financial services | 2022 |
| Colburn Group Limited | Professional & scientific | 2020 |
| Colby’S Copy and Consulting Limited | Administrative & support | 2022 |
| Cold END Services Ltd | Manufacturing | 2005 |
| Coldwell Lifestyle CIC | Arts & recreation | 2025 |
| Cole Clarke Racing Ltd | Arts & recreation | 2021 |
| Coleman Mercer Young Limited | Real estate | 2012 |
| Colin Ross Studio Limited | Professional & scientific | 2021 |
| Colin Sharpe Mechanical Services Limited | Construction | 2001 |
| Collaborative AI Limited | Information & communication | 2025 |
| Collabtitude Ltd | Professional & scientific | 2024 |
| Collective IP Limited | Information & communication | 2017 |
| Collins Excavations Ltd | Construction | 2018 |
| Collinson Farm Services Ltd | Agriculture & fishing | 2026 |
| Colmet Controls Limited | Administrative & support | 1998 |
| Cologistic Ltd | Transport & logistics | 2014 |
| Colombiage | Arts & recreation | 2007 |
| Colorworld (UK) Limited | Construction | 2014 |
| Colossal Catering Ltd | Hospitality | 2020 |
| Colosseo (Doncaster) Ltd | Hospitality | 2023 |
| Colosseum Hairdressing Limited | Other services | 2003 |
| Colosseum Limited | Extraterritorial | 2003 |
| Colossus Innovations Ltd | Information & communication | 2024 |
| Coltez Limited | Manufacturing | 2024 |
| Colu Trading Ltd | Wholesale & retail | 2025 |
| Colwill Contracting Limited | Construction | 2001 |
| Combat Academy (Franchising) Ltd | Arts & recreation | 2014 |