| Corsair Event Solutions Ltd | Extraterritorial | 2017 |
| Corsey UK Ltd | Hospitality | 2017 |
| Corsini Cleaning Contractors Ltd | Administrative & support | 2020 |
| Corsley Legal Limited | Professional & scientific | 2020 |
| Corsley Limited | Financial services | 2018 |
| Corsley Property Limited | Real estate | 2021 |
| Corso Ltd | Wholesale & retail | 2017 |
| Cortare Solutions Ltd | Administrative & support | 2021 |
| Cortecs Cerebrol Limited | Education | 2015 |
| Corten-Hawker Holdings Ltd | Construction | 2023 |
| Cortex AI Group Ltd | Information & communication | 2025 |
| Cortex Precision Limited | Manufacturing | 2025 |
| Corvette Products Limited | Manufacturing | 2000 |
| Corvette Properties Ltd | Real estate | 2015 |
| Corvidae Strategies Limited | Information & communication | 2025 |
| Corvinus Capital Ltd | Professional & scientific | 2012 |
| Coryton Consulting Limited | Professional & scientific | 2009 |
| COS Hospo Ltd | Hospitality | 2021 |
| COS Properties Limited | Real estate | 1999 |
| Cosar Global Limited | Wholesale & retail | 2024 |
| Cosart Limited | Manufacturing | 2019 |
| Cosgrove Builders Limited | Construction | 2010 |
| Cosgrove Group Limited | Financial services | 2022 |
| Cosgrove Homes Limited | Real estate | 2004 |
| Coshea Skincare Limited | Other services | 2016 |
| Coshop MAY Limited | Wholesale & retail | 2026 |
| Cosier Ltd | Construction | 2024 |
| Cosma LOR Limited | Wholesale & retail | 2025 |
| Cosmedicare Skin Clinic Ltd | Health & social care | 2006 |
| Cosmet UK Limited | Wholesale & retail | 2016 |
| Cosmetic City Skin Doctor Limited | Health & social care | 2019 |
| Cosmetic Info Update Limited | Professional & scientific | 2016 |
| Cosmetic Medicine Limited | Other services | 2021 |
| Cosmeticteethuk Ltd | Wholesale & retail | 2015 |
| Cosmic Art Limited | Arts & recreation | 2021 |
| Cosmic Marketing Group Limited | Information & communication | 2016 |
| Cosminnedelcu Ltd | Transport & logistics | 2019 |
| Cosmira Ltd | Other services | 2025 |
| Cosmix Limited | Information & communication | 2022 |
| Cosmo Bach Business Analysis Ltd | Information & communication | 2023 |
| Cosmo Property Developments Ltd | Real estate | 2019 |
| Cosmohome & More Ltd | Wholesale & retail | 2025 |
| Cosmon Ventures PC | | 2019 |
| Cosmopolitan Aesthetics Ltd | Other services | 2019 |
| Cosmotec Limited | Wholesale & retail | 2016 |
| Cosmoviola Ltd | Wholesale & retail | 2025 |
| Cossey Estates Ltd | Real estate | 2018 |
| Cost Effective Developments Ltd | Construction | 2019 |
| Costa Este Group Ltd | Professional & scientific | 2019 |
| Costume Services Limited | Other services | 2023 |
| Costycory Painting Ltd | Construction | 2024 |
| Cosy Cardiff Cwtch Ltd | Real estate | 2025 |
| Cosy Cardiff Ltd | Administrative & support | 2016 |
| Cosy Cinema Ltd | Administrative & support | 2020 |
| Cosy Cinema ST Mellons Ltd | Information & communication | 2025 |
| Cosy Homes SW Ltd | Real estate | 2020 |
| Cosy Horse Stables Ltd | Construction | 2018 |
| Cosywarm Heating and Plumbing Limited | Construction | 2011 |
| Cosywarm Servicing Limited | Construction | 2026 |
| Cotech Limited | Professional & scientific | 2009 |
| Cotega Group Limited | Administrative & support | 2017 |
| Coterie Groupe Limited | Other services | 2024 |
| Cotneus Limited | Wholesale & retail | 2025 |
| Cotsen & Company Limited | Professional & scientific | 2003 |
| Cotsen Consultants Ltd | Professional & scientific | 2011 |
| Cotswold Care Limited | Administrative & support | 2019 |
| Cotswold Homes & Building Developments Limited | Construction | 2024 |
| Cotswold Mainline Diesel Group Limited | Arts & recreation | 2023 |
| Cotswold Printing Co Limited | Manufacturing | 2014 |
| Cotswold Wears Ltd | Wholesale & retail | 2020 |
| Cotswoldgate Limited | Wholesale & retail | 2002 |
| Cotswoldkiwi Limited | Health & social care | 2015 |
| Cotswolds Social Limited | Other services | 2018 |
| Cottam Consultancy Ltd | Professional & scientific | 2025 |
| Cotton and Pulp Trading Ltd | Wholesale & retail | 2021 |
| Cotton Bay International Ltd | Wholesale & retail | 2025 |
| Cotton Mouton Diagnostics Ltd | Professional & scientific | 2014 |
| Cotton Tree Investments Limited | Real estate | 2017 |
| Cottrell Capital Ltd | Extraterritorial | 2015 |
| Cottrell Group Ltd | Financial services | 2024 |
| Cotup Property Ltd | Construction | 2024 |
| Cotyora Pardus Ltd | Construction | 2024 |
| Cougars London Ltd | Hospitality | 2024 |
| Couly Exports Ltd | Water & waste | 2016 |
| Council for Wales of Voluntary Youth Services Cyngor Cymreig Y Gwasanaethau Ieuenctid Gwirfoddol | Education | 2005 |
| Counsellor WJB SE Limited | Financial services | 2020 |
| Count on ME Accountancy Limited | Professional & scientific | 2022 |
| Counting Wells Limited | Professional & scientific | 2009 |
| Countisbury Fruit Limited | Wholesale & retail | 2021 |
| Countisbury Pizza Ltd | Hospitality | 2026 |
| Country Garden Roses Limited | Wholesale & retail | 2022 |
| Country Life Interiors Ltd | Wholesale & retail | 2016 |
| Country Weddings (Cardiff) Ltd | Hospitality | 2011 |
| Countrywide Employment Services 01 Ltd | Other services | 2019 |
| Countrywide Employment Services 02 Ltd | Administrative & support | 2020 |
| Countrywide Employment Services 03 Ltd | Administrative & support | 2021 |
| Countrywide Employment Services 04 Ltd | Administrative & support | 2020 |
| Countrywide Employment Services 06 Ltd | Administrative & support | 2021 |
| Countrywide Employment Services 07 Ltd | Administrative & support | 2021 |
| Countrywide Employment Services 08 Ltd | Administrative & support | 2022 |