| CNM Estates (Magnum) Limited | Construction | 2016 |
| CNM Estates (Red Lion Management) Limited | Construction | 2013 |
| Cnmp Limited | Professional & scientific | 2012 |
| CNP Studio Ltd | Professional & scientific | 2023 |
| CNR International (Trustees) Limited | Administrative & support | 1995 |
| CNR International (U.K.) Developments Limited | Mining & quarrying | 1971 |
| CNR International (U.K.) Investments Limited | Mining & quarrying | 1977 |
| CNR International (U.K.) Limited | Mining & quarrying | 1964 |
| Cnri (G.B.) Limited | Mining & quarrying | 2009 |
| CNS Northern Ltd | Administrative & support | 2009 |
| Co Energy (UK) Limited | Professional & scientific | 2020 |
| Co Energy Holdings Limited | Professional & scientific | 2020 |
| CO-OPR8 Investments Limited | Administrative & support | 2000 |
| Co. Corner Shop Ltd | Wholesale & retail | 2026 |
| Co.Man Group Ltd | Transport & logistics | 2026 |
| CO2 Consultants Ltd | Professional & scientific | 2005 |
| CO2 Impact Ltd | Information & communication | 2024 |
| Coach and Horses Rothwell (Leeds) Ltd | Hospitality | 2022 |
| Coach ESI Ltd | Arts & recreation | 2023 |
| Coach House Court (Wetherby) Limited | Households | 2008 |
| Coach House Sports Physiotherapy Clinic Limited | Health & social care | 2012 |
| Coached by Katy Ltd | Arts & recreation | 2020 |
| Coaches Stack Ltd | Education | 2026 |
| Coachhouse BD20 Ltd | Hospitality | 2022 |
| Coaching Achievement Limited | Professional & scientific | 2025 |
| Coachromona Ltd | Arts & recreation | 2024 |
| Coachtravel Jozef Popielarski Ltd | Transport & logistics | 2021 |
| Coak Base Ltd | Information & communication | 2024 |
| Coal Maris Limited | Professional & scientific | 2010 |
| Coalition K9 Ltd | Administrative & support | 2026 |
| Coast to Country Cafe Ltd | Hospitality | 2024 |
| Coastal Campers Scarborough Limited | Wholesale & retail | 2017 |
| Coater Sales & Service Limited | Manufacturing | 2006 |
| Coates & Co Consultancy Services Limited | Professional & scientific | 2010 |
| Coax Ltd | Construction | 2019 |
| Cobalt Project Investments (Hull - Sewell) Limited | Financial services | 2016 |
| Cobalt Project Investments (Hull) Limited | Administrative & support | 2005 |
| Cobalt Project Investments (Issuer) Limited | Administrative & support | 2013 |
| Cobalt Project Investments (Taycare) Limited | Administrative & support | 2008 |
| Cobalt Project Investments Limited | Administrative & support | 2013 |
| Cobalt Project Investments Limited Partnership | | 2013 |
| Cobble Hall Golf and Country Club Limited | Administrative & support | 2020 |
| Cobbydale Hospitality Ltd | Hospitality | 2019 |
| Cobco 738 Limited | Professional & scientific | 2006 |
| Cobden Solutions Limited | Professional & scientific | 2016 |
| Cobeau Limited | Wholesale & retail | 2002 |
| Cobloc Limited | Real estate | 2005 |
| Cobo Tankers & Services Limited | Wholesale & retail | 2018 |
| Coboodle Ltd | Real estate | 2016 |
| Cobourg Living Ltd | Real estate | 2012 |
| Cobox Limited | Professional & scientific | 2021 |
| Cobretti Ltd. | Financial services | 2022 |
| Coburg House Limited | Real estate | 2019 |
| Cobweb Retail Limited | Financial services | 2010 |
| Cocarla Limited | Transport & logistics | 2025 |
| Cockburn Heating Leeds Ltd | Construction | 2025 |
| Cockburn Multi Academy Trust | Education | 2016 |
| Cockburn Reach Independent School | Education | 2025 |
| Cockill Consultancy Ltd | Information & communication | 2024 |
| Cockshott Lane Stores Ltd | Wholesale & retail | 2017 |
| Coco Global Enterprise Ltd | Wholesale & retail | 2025 |
| Cocoa Cabana Ancoats Limited | Manufacturing | 2018 |
| Cocoa Cabana Limited | Hospitality | 2012 |
| Cocogs Ltd | Hospitality | 2026 |
| Coconitro Limited | Financial services | 2019 |
| Cocoon in the Park Limited | Arts & recreation | 2009 |
| Cocoon Labs Ltd | Manufacturing | 2014 |
| Cocoon Smart Repair Ltd | Wholesale & retail | 2025 |
| Cocoon Transform & Grow Ltd | Education | 2025 |
| Cocoonsafe Ltd | Information & communication | 2026 |
| Code AMP Ltd | Professional & scientific | 2016 |
| Code IQ Limited | Information & communication | 2017 |
| Code Train Ltd | Information & communication | 2020 |
| Code Work Labs Limited | Information & communication | 2022 |
| Codebuds Ltd | Information & communication | 2023 |
| Coders 101 Limited | Information & communication | 2022 |
| Codes of Steel Ltd | Information & communication | 2025 |
| Codesde Limited | Professional & scientific | 2024 |
| Codesigned Ltd | Wholesale & retail | 2015 |
| Codesolver Ltd | Information & communication | 2025 |
| Codetrail Ltd | Information & communication | 2018 |
| Codetronix Limited | Manufacturing | 2017 |
| Codevio Ltd | Information & communication | 2021 |
| Codeway Technology Solutions Ltd | Administrative & support | 2016 |
| Codexial Ltd | Information & communication | 2025 |
| Codey Creative Ltd | Information & communication | 2019 |
| Codi Investments Limited | Professional & scientific | 2022 |
| Codi Kitchen Ltd | Wholesale & retail | 2022 |
| Codi Takeaway Limited | Hospitality | 2023 |
| Codor Ltd | Professional & scientific | 2025 |
| Codswallop CIC | Arts & recreation | 2017 |
| Cody-Magee Property Ltd | Households | 2024 |
| Coe's Fisheries (Crossgates) Limited | Hospitality | 1962 |
| Coe's Fisheries Holdings Limited | Financial services | 2012 |
| Coedlys Property Letting’S and Maintenance Ltd | Real estate | 2022 |
| Coensus Ltd | Real estate | 2021 |
| Coensus Property Solutions Ltd | Real estate | 2025 |
| Coey & Smith Limited | Hospitality | 2025 |
| Cofa Limited | Manufacturing | 2024 |
| Coffee & Smoothiemania Limited | Wholesale & retail | 2014 |