| CMI Interior Limited | Construction | 2003 |
| CMI Management Limited | Professional & scientific | 2006 |
| CMI Studio Ltd | Professional & scientific | 2016 |
| CMI Telecoms Services Limited | Administrative & support | 2008 |
| CMI Workplace Limited | Professional & scientific | 2005 |
| CMK Bumper Paint Ltd | Wholesale & retail | 2025 |
| CMK Foods Ltd | Wholesale & retail | 2020 |
| CMK Legalisation Limited | Administrative & support | 2013 |
| CMK Stays Ltd | Hospitality | 2026 |
| CML Developments (Home Counties) Limited | Real estate | 2019 |
| Cmmk Ltd | Professional & scientific | 2014 |
| CMS Events Limited | Administrative & support | 2005 |
| CMS Milton Keynes Limited | Professional & scientific | 2013 |
| CMT Engineering and Development Limited | Wholesale & retail | 2011 |
| CMT Logistics Limited | Transport & logistics | 2025 |
| Cmtn Consultancy Ltd | Information & communication | 2018 |
| CMW Solutions Limited | Administrative & support | 2012 |
| CMX Universal Ltd | Information & communication | 2024 |
| CN Tools Ltd | Wholesale & retail | 2020 |
| CNB Rail & Metro Services Limited | Professional & scientific | 2016 |
| CNC4YOU Limited | Wholesale & retail | 2012 |
| Co Events Limited | Administrative & support | 2017 |
| Co Virtual Services Ltd | Administrative & support | 2023 |
| Co-Living Property Investments Ltd | Real estate | 2023 |
| Co-Surveys Limited | Professional & scientific | 1979 |
| Coach Chicksen Limited | Education | 2021 |
| Coach Forever Ltd | Other services | 2015 |
| Coach House Media Limited | Professional & scientific | 1993 |
| Coach Kirkham Ltd | Other services | 2023 |
| Coach ME IF YOU CAN Ltd | Professional & scientific | 2019 |
| Coalville Glass & Glazing Co. Limited | Manufacturing | 1996 |
| Coastline Spirits Ltd | Wholesale & retail | 2022 |
| Cobbys Company Limited | Health & social care | 2023 |
| Cobden Surveyors Limited | Professional & scientific | 1993 |
| Cobel Trans Limited | Construction | 2016 |
| Cobos Ltd | Wholesale & retail | 2002 |
| Cock and Bull Creative Ltd | Financial services | 2025 |
| Cocoashed Ltd | Information & communication | 2009 |
| Cocoearth Private Ltd | Wholesale & retail | 2025 |
| Cocos Coffee House Ltd | Hospitality | 2024 |
| Cocoswirl Ltd | Other services | 2024 |
| Cocreate Events Limited | Hospitality | 2025 |
| Coda Facades Ltd | Construction | 2022 |
| Coda Store Ltd | Wholesale & retail | 2024 |
| Codasine Ltd | Professional & scientific | 2020 |
| Code 1 Global Ltd | Professional & scientific | 2026 |
| Code and Cadence Ltd | Information & communication | 2026 |
| Code D Technologies Ltd | Information & communication | 2021 |
| Code Environments Limited | Professional & scientific | 2016 |
| Code Forge Ltd | Information & communication | 2019 |
| Code Monkeys U.K. Ltd | Information & communication | 2025 |
| Code Red Consultancy Limited | Professional & scientific | 1997 |
| Codebreaker Spice Limited | Hospitality | 2022 |
| Codecrackers Limited | Information & communication | 2025 |
| Coded Cognition Limited | Information & communication | 2017 |
| Codeforge Solutions Ltd | Information & communication | 2025 |
| Codehub 200 Limited | Administrative & support | 2019 |
| Codelessuk Ltd | Wholesale & retail | 2024 |
| Codelinx Ltd | Information & communication | 2025 |
| Codelogic Aidc Ltd | Information & communication | 2012 |
| Codem Digital Limited | Information & communication | 2015 |
| Coden Limited | Real estate | 2019 |
| Codenia Ltd | Professional & scientific | 2019 |
| Codestorm Labs Limited | Information & communication | 2024 |
| Codetyme UK Ltd | Information & communication | 2025 |
| Codex Dominium Ltd | Information & communication | 2026 |
| Codrai Electrical Services Limited | Construction | 2012 |
| Coffee Insight Ltd | Wholesale & retail | 2025 |
| Cogen Limited | Professional & scientific | 2023 |
| Cognify Search Ltd | Administrative & support | 2023 |
| Cognita Bondco Parent Limited | Financial services | 2015 |
| Cognita Financing PLC | Financial services | 2015 |
| Cognita Funding 1 Limited | Financial services | 2009 |
| Cognita Holdings Limited | Financial services | 2004 |
| Cognita International Holdings Limited | Financial services | 2007 |
| Cognita Limited | Financial services | 2004 |
| Cognita Midco Limited | Financial services | 2015 |
| Cognita Schools Limited | Education | 1988 |
| Cognita UK Brazil Holdings Limited | Financial services | 2012 |
| Cognita UK Canada Holdings Limited | Financial services | 2024 |
| Cognita UK Holdings Limited | Financial services | 2008 |
| Cognita UK KSA Holdings Limited | Financial services | 2024 |
| Cognita UK Mexico Holdings Limited | Extraterritorial | 2010 |
| Cognita UK South Korea Holdings Limited | Financial services | 2024 |
| Cognita UK USA Holdings Limited | Financial services | 2022 |
| Cognitiva Health Ltd | Education | 2025 |
| Cognyfi Limited | Health & social care | 2026 |
| COL Holdings Limited | Professional & scientific | 2016 |
| Col-Bon Limited | Administrative & support | 2020 |
| Cola Properties Limited | Real estate | 2023 |
| Colareza Cars Limited | Wholesale & retail | 2019 |
| Colcarl Ltd | Public administration | 2023 |
| Coldsmoking Limited | Manufacturing | 2013 |
| Cole and Cade Ltd. | Manufacturing | 2024 |
| Cole Brooker Ltd | Information & communication | 2025 |
| Cole Pendrey Investments Ltd | Financial services | 2022 |
| Coleman Asset Management Group Limited | Administrative & support | 2014 |
| Coleman Flooring UK Limited | Construction | 2007 |
| Coles Gardening Services Limited | Administrative & support | 2016 |
| Colin Francis Builders Limited | Construction | 1990 |