| Cooling Spaces Air Conditioning Ltd | Construction | 2025 |
| Coombswood Education Limited | Education | 2023 |
| Cooper Hayes Limited | Professional & scientific | 2009 |
| Cooper Lighting Solutions UK Limited | Manufacturing | 2019 |
| Copenhagen Bidco Limited | Financial services | 2018 |
| Copenhagen Finco Limited | Financial services | 2018 |
| Copper and Cloves Ltd. | Hospitality | 2018 |
| Copper Trading Solutions Limited | Wholesale & retail | 2011 |
| Coppergate Kenworthy LP | | 2018 |
| Corby NO 2 Limited | Construction | 2020 |
| Cord International Limited | Wholesale & retail | 1987 |
| Cordial Investments Limited | Households | 2021 |
| Cordial Investments SPV 1 Ltd | Construction | 2022 |
| Cordial Investments SPV 2 Ltd | Construction | 2024 |
| Cordial Investments SPV 3 Ltd | Construction | 2024 |
| Core Atlantic Ltd | Information & communication | 2020 |
| Core Group (Global) Limited | Extraterritorial | 2020 |
| Core Group Limited | Construction | 2004 |
| Core Group USA Ltd | Professional & scientific | 2023 |
| Core People Group Ltd | Administrative & support | 2025 |
| Core People Ltd | Administrative & support | 2013 |
| Core People Services Ltd | Professional & scientific | 2018 |
| Core Rail Ltd | Administrative & support | 2018 |
| Core Union Ltd | Wholesale & retail | 2015 |
| Corelights Trading Ltd | Wholesale & retail | 2026 |
| Corepoint Data Centres Ltd | Construction | 2026 |
| Corescaler Limited | Wholesale & retail | 2025 |
| Corina Crysler Limited | Information & communication | 2025 |
| Corinco Limited | Hospitality | 2015 |
| Corkage Ltd | Wholesale & retail | 2014 |
| Cormat Group Ltd | Professional & scientific | 2020 |
| Cormat UK Ltd | Professional & scientific | 2018 |
| Cornerstone Secure Housing Group Ltd | Hospitality | 2026 |
| Corporate HR Solutions Limited | Professional & scientific | 2004 |
| Corptech Consulting Limited | Information & communication | 2024 |
| Corrosion Courses (UK) Ltd | Professional & scientific | 2011 |
| Corrosion Courses Ltd | Education | 2009 |
| Corrosion Service Company Europe Limited | Professional & scientific | 2009 |
| Corston Investments Limited | Real estate | 2021 |
| Corua Group Limited | Information & communication | 2024 |
| Corumbe Investments Limited | Construction | 2012 |
| Corveritas Limited | Professional & scientific | 2026 |
| Cosmic Equipment UK Limited | Manufacturing | 2006 |
| Costa Solar 009 Limited | Financial services | 2019 |
| Costa Solar 012 Limited | Financial services | 2019 |
| Costheta Consulting Ltd | Professional & scientific | 2017 |
| Cosy Connect Ltd | Wholesale & retail | 2023 |
| Cosy Solutions UK Ltd | Other services | 2021 |
| Cotech Building Careers Limited | Administrative & support | 2003 |
| Cottrell Creative Limited | Professional & scientific | 2019 |
| Cotts Chauffeur Ltd | Transport & logistics | 2021 |
| Coulthwaite Group Ltd | Professional & scientific | 2023 |
| Counselling Network Limited | Information & communication | 2013 |
| Counterr Limited | Professional & scientific | 2023 |
| Country Africa Limited | Information & communication | 2021 |
| Countryside Property Services Limited | Wholesale & retail | 1994 |
| Countrywide Property Investments (UK) Limited | Professional & scientific | 2008 |
| County Catering & Leisure Limited | Real estate | 1990 |
| County Catering & Leisure Properties Limited | Real estate | 1992 |
| County Marquees (Hire) Limited | Administrative & support | 2017 |
| COURAGE2LEAD Ltd | Administrative & support | 2011 |
| Coutts-De Lisle & Co. Limited | Construction | 1990 |
| Couvert Event Hire Limited | Administrative & support | 2011 |
| Covermount Limited | Real estate | 1980 |
| Coxcombe Lane SPV Ltd | Construction | 2024 |
| CP Healthtech Ltd | Information & communication | 2024 |
| CP Legal Group Limited | Other services | 2017 |
| Cpopovici Project Ltd | Professional & scientific | 2018 |
| Cppforge Ltd | Information & communication | 2026 |
| CQX Limited | Information & communication | 2011 |
| Cracked Foodservice Marketing Limited | Professional & scientific | 2016 |
| Crafted Outdoors Ltd | Construction | 2025 |
| Craig Durrant Limited | Wholesale & retail | 2023 |
| Cramond & Co Ltd | Professional & scientific | 2022 |
| Cranbrook Property Investment Limited | Real estate | 2010 |
| Crane Maintain Property Maintenance Ltd | Construction | 2023 |
| Crane Media Limited | Information & communication | 2015 |
| Cranfold (Wormley) Limited | Construction | 2025 |
| Cranfold Construction Limited | Construction | 2018 |
| Cranfold Developments Limited | Construction | 1991 |
| Cranfold Developments PP Limited | Construction | 2021 |
| Cranfold Investments Limited | Real estate | 2018 |
| Cranleigh and South Eastern Agricultural Society | Agriculture & fishing | 1981 |
| Cranleigh Builders Limited | Construction | 1980 |
| Cranleigh Fixing Company Limited | Construction | 2005 |
| Cranleigh Recruitment Holdings Limited | Financial services | 2014 |
| Cranleigh Scientific Limited | Administrative & support | 2011 |
| Cranleigh Tyre Company Limited | Wholesale & retail | 1985 |
| Cranleigh Village Health Trust | Health & social care | 2001 |
| Cranwell Investments UK Limited | Administrative & support | 2015 |
| Crashassessor UK Ltd | Wholesale & retail | 2018 |
| Crawford Mackenzie Ltd | Professional & scientific | 2024 |
| CRD Build Group Limited | Construction | 2022 |
| Creagh Consulting Ltd | Information & communication | 2026 |
| Create the Market Ltd | Financial services | 2015 |
| Creation Consultancy Limited | Professional & scientific | 2019 |
| Creative Allsorts Ltd | Wholesale & retail | 2023 |
| Creative Arts Kids Ltd | Arts & recreation | 2021 |
| Creative Packers UK Limited | Wholesale & retail | 2026 |
| Creative Technologist Limited | Information & communication | 2011 |