| Clinicguideng Ltd | Extraterritorial | 2021 |
| Clinocall Limited | Extraterritorial | 2021 |
| Clinv Limited | Information & communication | 2020 |
| Clive Barrington Richley Limited | Extraterritorial | 2022 |
| Clives Motor Group Ltd | Wholesale & retail | 2025 |
| Clixico Ltd | Professional & scientific | 2025 |
| CLM Content Limited | Information & communication | 2026 |
| Cloisters Bistro Limited | Hospitality | 2016 |
| Close Bookkeeping and Accounting Ltd | Professional & scientific | 2024 |
| Close Number 6 Limited | Professional & scientific | 1996 |
| Cloth & Bottle Cleaning Co Ltd | Administrative & support | 2025 |
| Cloth & Bottle Midco Ltd | Administrative & support | 2025 |
| CLOTHES4ALL Limited | Wholesale & retail | 2025 |
| Clothier Training and Consultancy Ltd | Professional & scientific | 2024 |
| Cloud City Vapes Ltd | Wholesale & retail | 2026 |
| Cloud Journey LLP | | 2021 |
| Cloud Journey Partners Ltd | Information & communication | 2020 |
| Cloud Nine Cleaners Ltd | Administrative & support | 2025 |
| Cloud Prep Limited | Information & communication | 2023 |
| CLOUD9 Fibre Ltd | Information & communication | 2020 |
| CLOUD9 Music Productions Ltd | Information & communication | 2022 |
| CLOUD9 Serviced Accommodation Ltd | Hospitality | 2019 |
| Cloudcor Ltd | Construction | 2018 |
| Cloudnexa Recruitment Ltd | Information & communication | 2025 |
| Cloudstream Limited | Information & communication | 2023 |
| Cloudwear Limited | Manufacturing | 2022 |
| Clough Construction Services Limited | Construction | 2014 |
| Clover Building Projects Ltd | Construction | 2020 |
| Clover Haulage Ltd | Transport & logistics | 2021 |
| Clover Properties 2024 Ltd | Construction | 2024 |
| Cloverbrook Property Management Limited | Real estate | 1993 |
| Cloverstack Ltd | Information & communication | 2026 |
| Club Catering Services International Ltd | Administrative & support | 2020 |
| Club Eclat Ltd | Administrative & support | 2017 |
| Club for ALL Ltd | Arts & recreation | 2015 |
| Club M Lingerie Limited | Wholesale & retail | 2022 |
| Club Opulent Ltd | Financial services | 2024 |
| Clues Clothing Limited | Wholesale & retail | 2011 |
| Cluster Building Ltd | Information & communication | 2024 |
| Clutch Integrated Services Ltd | Information & communication | 2023 |
| Clutter & Clean Ltd | Administrative & support | 2026 |
| CLW Safety Consultants Ltd | Professional & scientific | 2026 |
| Clyde Potatoes Seeds Ltd | Manufacturing | 2020 |
| Clydesdale Gardens, Newborough, Management Company Limited | Real estate | 2015 |
| CM Accounts Ltd | Professional & scientific | 2011 |
| CM Decorating Limited | Other services | 2013 |
| CM Demolition Ltd | Water & waste | 2022 |
| CM Holdings Group UK & Ireland Limited | Manufacturing | 2024 |
| CM Property Solutions UK and Ireland Limited | Hospitality | 2022 |
| CM Trans Logistics Ltd | Administrative & support | 2014 |
| Cmdl (UK) Ltd | Education | 2026 |
| CMH Finance Systems Limited | Professional & scientific | 2023 |
| CMH Gardening Ltd | Other services | 2007 |
| CML Decorators Limited | Construction | 1992 |
| CMM Testing Solutions Limited | Information & communication | 2016 |
| CMM168 Limited | Wholesale & retail | 2020 |
| CN LEI Limited | Information & communication | 2021 |
| CN Rock Investments Ltd | Real estate | 2022 |
| CNC Lounge Ltd | Hospitality | 2026 |
| CND Trans Ltd | Transport & logistics | 2020 |
| Cndle Studio Ltd | Manufacturing | 2019 |
| Cnyts Consulting Ltd | Administrative & support | 2025 |
| Co&Mi Trans Ltd | Administrative & support | 2020 |
| Co-Foundry Offices Ltd | Real estate | 2018 |
| Co-Op Group Travel 2 Holdings Limited | Administrative & support | 2010 |
| Coaching With ZEE Ltd | Information & communication | 2023 |
| Coacora International Limited | Manufacturing | 2018 |
| Coalesce IT Ltd | Information & communication | 2007 |
| Coast Rental Ltd | Real estate | 2020 |
| Coastal Collection Limited | Hospitality | 2025 |
| Coastal View Windows and Doors Limited | Construction | 2017 |
| Coastfields Leisure Limited | Hospitality | 1972 |
| Coates Accountants Limited | Professional & scientific | 2023 |
| Coates Business Services Ltd | Professional & scientific | 2009 |
| Coates Notes C.I.C. | Arts & recreation | 2023 |
| Coates Notes Music Services Limited | Wholesale & retail | 2008 |
| Cobaltfox Limited | Information & communication | 2026 |
| Cobb's Engineering Ltd | Professional & scientific | 2020 |
| Cobbin Ltd | Construction | 2026 |
| Cobblestone City Properties Ltd | Real estate | 2024 |
| Cobbs Integrated Trade Limited | Wholesale & retail | 2025 |
| Cobham MSA Business Centre Limited | Real estate | 2012 |
| Cobra Logistics Ltd | Transport & logistics | 2016 |
| Cobrook Limited | Wholesale & retail | 2021 |
| Cociu Trans Ltd | Transport & logistics | 2019 |
| Cockrams Properties Ltd | Real estate | 2021 |
| Cocomore Style Limited | Wholesale & retail | 2022 |
| Coco’S Caribbean Kitchen Ltd | Hospitality | 2020 |
| Codefactors Ltd | Information & communication | 2011 |
| Codem Composites Limited | Manufacturing | 2009 |
| Codem Environmental Limited | Manufacturing | 2020 |
| Codem Group Limited | Extraterritorial | 2015 |
| Codemyte Ltd | Information & communication | 2025 |
| Codename Media Limited | Information & communication | 2010 |
| Codman Construction Limited | Construction | 1999 |
| Coelco Group Limited | Financial services | 2025 |
| Coelco Medical Limited | Health & social care | 2019 |
| Coelco Residential Limited | Real estate | 2021 |
| Coeliana Integrated Services Limited | Health & social care | 2019 |
| Coengineers Limited | Information & communication | 2025 |