| Colesbrook Haulage Ltd | Transport & logistics | 2014 |
| Coleshill Key Services Limited | Other services | 2008 |
| Colestocks Operations Ltd | Transport & logistics | 2014 |
| Colfox School Services Limited | Construction | 1997 |
| Colibri Studio Ltd | Arts & recreation | 2026 |
| Colin Brown Contractors Limited | Construction | 2001 |
| Colin Hall Consulting Limited | Financial services | 2021 |
| Colindale Property Limited | Real estate | 2019 |
| Collaborative Consultancy Services Limited | Professional & scientific | 2022 |
| Collaborative Edge Limited | Professional & scientific | 2017 |
| Collaborative Product Realisation Limited | Professional & scientific | 2025 |
| Collado Collins Limited | Professional & scientific | 2004 |
| Collect and Display Ltd | Wholesale & retail | 2020 |
| Collectcardscollective Ltd | Wholesale & retail | 2026 |
| Collections Trust | Education | 1977 |
| Collective Minds Gaming Company Inc. Limited | Information & communication | 2017 |
| College Court Conference Centre Limited | Hospitality | 2007 |
| College Garth Limited | Other services | 2017 |
| College of Medicine and Healing Arts Limited | Health & social care | 2011 |
| Collegia Care Limited | Health & social care | 1989 |
| Collier Plumbing & Heating Ltd | Construction | 2023 |
| Collingbourne Effective Ltd | Transport & logistics | 2014 |
| Collingham Estates Ltd | Real estate | 2021 |
| Collingwood Motors Limited | Wholesale & retail | 2019 |
| Collins Distributors Ltd | Wholesale & retail | 2026 |
| Collis Properties Limited | Construction | 2013 |
| Collis Property Ltd | Real estate | 2023 |
| Colman & Dhillon Limited | Professional & scientific | 2026 |
| Colmaur Investments Limited | Real estate | 2021 |
| Colophon Broadcasting Ltd | Information & communication | 2013 |
| Color-Chem (Europe) Limited | Wholesale & retail | 2002 |
| Colorgrasp Limited | Information & communication | 2021 |
| Colour Check Services Ltd | Professional & scientific | 2009 |
| Colour Fish Limited | Professional & scientific | 2009 |
| Colour Paints Ltd | Wholesale & retail | 2009 |
| Colour Point Ltd | Administrative & support | 2017 |
| Colourbank Stamford Limited | Wholesale & retail | 2005 |
| Colourkey Limited | Professional & scientific | 2024 |
| Colourkit Paint Systems Limited | Wholesale & retail | 2001 |
| Colourprint G.B. Limited | Extraterritorial | 2013 |
| Colours Dyers (UK) Limited | Manufacturing | 2010 |
| Colours Dyers Holdings Limited | Financial services | 2020 |
| Colourtech Bodywork Limited | Wholesale & retail | 2014 |
| Colourways Textiles Factory Limited | Wholesale & retail | 2021 |
| Colourways Textiles Limited | Wholesale & retail | 2020 |
| Colourwise Powder Coaters Limited | Extraterritorial | 1997 |
| Colourworks DYE House Limited | Manufacturing | 2019 |
| Colston Gardens Residents Management Company Limited | Households | 2025 |
| Coltman Group Limited | Professional & scientific | 2024 |
| Colton Street Management Company Limited | Households | 2010 |
| Columbus Group Limited | Real estate | 2025 |
| Columbus Vehicle Specialists Limited | Wholesale & retail | 2011 |
| Colwell College Limited | Education | 2016 |
| Comac Europe Limited | Wholesale & retail | 1999 |
| Comardy Ltd | Health & social care | 2018 |
| Combine Services Ltd | Administrative & support | 2025 |
| Combined Effort Consulting Limited | Information & communication | 2001 |
| Comco Accessories UK Ltd | Information & communication | 2019 |
| Comdev Creative Limited | Manufacturing | 2018 |
| Come Together Community Support Ltd | Construction | 2019 |
| Comfort Air AC Ltd | Energy | 2025 |
| Comfort Clothing Ltd | Wholesale & retail | 2017 |
| Comfort Discharge & Reablement Services Private Limited | Health & social care | 2017 |
| Comfort Hub and Care Ltd | Real estate | 2025 |
| Comfort Properties Limited | Real estate | 2009 |
| Comfort Rise Care Limited | Health & social care | 2024 |
| Comfort Travel Group UK Limited | Administrative & support | 2026 |
| Comforting Companions Ltd | Administrative & support | 2025 |
| Comfy Home Properties Ltd | Real estate | 2021 |
| Comilian Ltd | Hospitality | 2010 |
| Comix Engineering Ltd | Manufacturing | 2026 |
| Comm 1 Ltd | Other services | 2023 |
| Comm-Serv (Leicester) Ltd | Administrative & support | 2025 |
| Command Capital Ltd | Real estate | 2022 |
| Commerce International Ltd | Hospitality | 2004 |
| Commerce Utilities Limited | Administrative & support | 2018 |
| Commercia Specialist Finance Ltd | Financial services | 2026 |
| Commercial & Business Property Consultants Ltd | Real estate | 2025 |
| Commercial Aluminium Shop Fronts Ltd | Manufacturing | 2011 |
| Commercial and Domestic Contractors Limited | Construction | 2018 |
| Commercial Asset Investments Ltd | Wholesale & retail | 2021 |
| Commercial Associates Limited | Wholesale & retail | 1986 |
| Commercial Break Limited | Professional & scientific | 2003 |
| Commercial Catering Equipment Ltd | Wholesale & retail | 2018 |
| Commercial Cleaners Only Limited | Administrative & support | 2026 |
| Commercial Diving Technical Services Ltd | Manufacturing | 2024 |
| Commercial Kitchen Designs Ltd | Construction | 2025 |
| Commercial Protection. Ltd | Administrative & support | 2024 |
| Commercial Waste Recycling Limited | Water & waste | 2012 |
| Committed Global Healthcare Limited | Health & social care | 2021 |
| Commodities & Textiles Ltd | Manufacturing | 2011 |
| Commonground Marketing Ltd | Professional & scientific | 2023 |
| Commonwealth Electrical Services Ltd | Construction | 2018 |
| Commpete Technology Services Limited | Professional & scientific | 1999 |
| Commture 365 Limited | Wholesale & retail | 2018 |
| Commture Consultancy Ltd | Professional & scientific | 2015 |
| Commture Ltd | Wholesale & retail | 2015 |
| COMMUNIC8TECH Ltd | Information & communication | 2024 |
| Communicate NOW Ltd | Professional & scientific | 2022 |
| Communications Infrastructure Services Ltd | Information & communication | 2022 |