| CMH Prime Holdings Ltd | Real estate | 2025 |
| CML Services London Limited | Real estate | 2011 |
| CMO Construction Ltd | Construction | 2023 |
| CMR Care Limited | Administrative & support | 2022 |
| CMR Properties Group Ltd | Real estate | 2023 |
| CMS Tiling Ltd | Construction | 2020 |
| Cmyk Media Limited | Education | 2021 |
| CNA Promotions Limited | Arts & recreation | 2025 |
| CNC Building Supplies Limited | Real estate | 1994 |
| CNC International Ltd | Wholesale & retail | 2025 |
| CNET-2K Limited | Information & communication | 2005 |
| CNK Drylining Ltd | Construction | 2023 |
| CNL Interiors Limited | Construction | 2017 |
| CNP Building Services Ltd | Construction | 2026 |
| CNS Housing Limited | Real estate | 2023 |
| CNS Technologies Limited | Wholesale & retail | 2020 |
| CNT Serv Ltd | Construction | 2017 |
| Cntr Ltd | Information & communication | 2022 |
| Co & Construction Ltd | Construction | 2021 |
| Co Property One Limited | Real estate | 2025 |
| Co&Sons Limited | Construction | 2019 |
| Coach House Delivery and Maintenance Limited | Wholesale & retail | 2025 |
| Coach House Furniture Suppliers Limited | Wholesale & retail | 2025 |
| Coachbarn Boarding Kennels Limited | Other services | 2018 |
| Coachbarn Cattery Limited | Other services | 2026 |
| Coastal Care Essex Ltd | Health & social care | 2026 |
| Coastal Rest Home Essex Ltd | Health & social care | 2026 |
| Coastline Hospitality Academy CIC | Health & social care | 2024 |
| Cobb Scaffolding Limited | Construction | 2014 |
| Cobblers Cafe & Bistro Ltd | Hospitality | 2025 |
| Coborn Services Ltd | Administrative & support | 2012 |
| Coccodrillo UK Ltd | Wholesale & retail | 2025 |
| Cockney BOY Limited | Information & communication | 2010 |
| Coco Cake's UK & Gustul DIN Copilarie Ltd | Hospitality | 2022 |
| Coco Clifton Coffee Limited | Hospitality | 2024 |
| Cocohutz Limited | Hospitality | 2024 |
| Coconut Bay Restaurants Ltd | Hospitality | 2026 |
| Coconut Garden Property Ltd | Real estate | 2015 |
| Cocreative Ltd | Wholesale & retail | 2023 |
| COD Buffet Limited | Hospitality | 2012 |
| COD Logistic Ltd | Transport & logistics | 2024 |
| Code and Keys Ltd | Information & communication | 2026 |
| Code Creators Ltd | Wholesale & retail | 2025 |
| CODE2IT Limited | Administrative & support | 2016 |
| Codebale Limited | Information & communication | 2011 |
| Coded ALM Consulting Limited | Information & communication | 2015 |
| Coded Property Limited | Real estate | 2020 |
| Coded Security Systems Ltd | Administrative & support | 2016 |
| Codeinvokers Limited | Information & communication | 2024 |
| Codeplexus Ltd | Information & communication | 2010 |
| Codeq Technologies Ltd | Information & communication | 2024 |
| Codex Tiling Ltd | Construction | 2020 |
| Codi Events Ltd | Administrative & support | 2025 |
| Codigo Technologies Ltd | Information & communication | 2019 |
| Coe-Tech Ltd | Information & communication | 2025 |
| Coeels Ltd | Administrative & support | 2011 |
| Coeus Consultancy Limited | Professional & scientific | 2014 |
| Coffe Roma Express Ltd | Hospitality | 2022 |
| Coffee People Limited | Manufacturing | 2023 |
| Coffeegram Ltd | Wholesale & retail | 2015 |
| Coffeepedia Limited | Hospitality | 2023 |
| Coffice Ltd | Other services | 2016 |
| Cogger's in Bloom Ltd | Wholesale & retail | 2017 |
| Cognigen Ltd | Information & communication | 2024 |
| Cognivista Ltd | Wholesale & retail | 2025 |
| Coldco Group Ltd | Wholesale & retail | 2014 |
| Coldco Ltd | Wholesale & retail | 2026 |
| Cole & Rose Services Limited | Hospitality | 2026 |
| Coleman Wealth Management UK Ltd | Professional & scientific | 2022 |
| Coligo Capital Limited | Financial services | 2022 |
| Coligo Holdings Limited | Financial services | 2022 |
| Coligo Limited | Administrative & support | 2018 |
| Colin Bull Swimming Limited | Arts & recreation | 2011 |
| Colindore LLP | | 2015 |
| Collab With US Ltd | Professional & scientific | 2026 |
| Collective Care Ltd | Health & social care | 2023 |
| Collective Consultancy Ltd | Professional & scientific | 2014 |
| Collective Finance Ltd | Financial services | 2026 |
| Collective Group and Construction Limited | Construction | 2024 |
| Collective Online Media Ltd | Information & communication | 2026 |
| Collective Properties Ltd | Real estate | 2014 |
| Collectors Market Ltd | Wholesale & retail | 2026 |
| College Cameras Limited | Wholesale & retail | 1979 |
| College London City Ltd | Education | 2016 |
| Collegeland Care Home Limited | Health & social care | 2025 |
| Collektus Limited | Wholesale & retail | 2020 |
| Collier & Company Ltd. | Administrative & support | 2004 |
| Collingham Consultancy Ltd | Information & communication | 2018 |
| Collinghurst Limited | Construction | 2023 |
| Collisons Billposting Limited | Administrative & support | 2009 |
| Colombo Food Station Ltd | Hospitality | 2024 |
| Color Joy Events Ltd | Wholesale & retail | 2026 |
| Colorful Smiles Ltd | Wholesale & retail | 2024 |
| Colourmatch Print Ltd | Manufacturing | 2017 |
| Colourscript Ltd. | Manufacturing | 2019 |
| Colourvision Holdings Limited | Financial services | 2026 |
| Colson Services Limited | Administrative & support | 2005 |
| Coltransauto Limited | Construction | 2023 |
| Columba Design Ltd | Extraterritorial | 2019 |
| Columbus Holdings Management Limited | Professional & scientific | 2020 |