| Cook`S Tree Surgeons (Wimbledon) Limited | Extraterritorial | 2009 |
| Coolldn Ltd | Construction | 2025 |
| Coombes Brickwork Limited | Construction | 2005 |
| Copala Limited | Wholesale & retail | 2023 |
| Coparent AI App Limited | Information & communication | 2026 |
| Copeland Consultants Limited | Public administration | 2026 |
| Copper Oak Carpentry Ltd | Construction | 2022 |
| Copyright Licensing Consultancy Ltd | Manufacturing | 2017 |
| Core Vision Trading and Decoration Ltd | Construction | 2025 |
| Corefix Maintenance Ltd | Construction | 2025 |
| Corespan General Contracting Company Ltd. | Construction | 2023 |
| Corinthia Cargo Ltd | Transport & logistics | 2018 |
| Corl Ltd | Construction | 2025 |
| Cornerstone Invests Limited | Construction | 2018 |
| Cornerstones Invests Limited | Real estate | 2025 |
| Cortelek Ventures Ltd | Real estate | 2020 |
| Corvit Networks Ltd | Wholesale & retail | 2024 |
| COS Services Limited | Construction | 1986 |
| Cosmic Care Ltd | Health & social care | 2008 |
| Cosmopolitan Accountants Ltd | Professional & scientific | 2016 |
| Coster Harvey Limited | Real estate | 2004 |
| Country Girl Fashion Limited | Wholesale & retail | 2024 |
| Couture Counsel Limited | Administrative & support | 2021 |
| Covid Cat Limited | Administrative & support | 2020 |
| Cowie Sahl Ltd | Administrative & support | 2024 |
| COX Holdings Limited | Real estate | 1984 |
| CR2 Estate Agents Ltd | Real estate | 2019 |
| CR2 Projects Ltd | Construction | 2025 |
| CR4 MOT Village & Repair Centre Ltd | Wholesale & retail | 2026 |
| Craftora Selling Ltd | Wholesale & retail | 2026 |
| Crafture Ltd | Wholesale & retail | 2024 |
| CRE8 Electricity Ltd | Manufacturing | 2013 |
| Creamy and Bites Ltd | Hospitality | 2021 |
| Creamy Treats Ltd | Hospitality | 2025 |
| Creative Aluminium Limited | Manufacturing | 2020 |
| Creative Aluminium Solutions Ltd | Manufacturing | 2012 |
| Creative Bay Limited | Extraterritorial | 2018 |
| Creative Minds Construction Ltd | Construction | 2022 |
| Creative Rents Ltd | Real estate | 2021 |
| Creative Revolution Ltd | Information & communication | 2010 |
| Creativescape Ltd | Wholesale & retail | 2023 |
| Creator Business OS Ltd | Information & communication | 2026 |
| CROISSANT22 Ltd | Information & communication | 2025 |
| Crown Coffee House Ltd | Hospitality | 2026 |
| Crown King Ltd | Wholesale & retail | 2020 |
| Crown Lane Productions Limited | Information & communication | 2007 |
| Crown Law Solicitors LLP | | 2020 |
| Crown London Cosmetic Trading Ltd | Wholesale & retail | 2025 |
| Croydon Bouncy Castles Ltd | Arts & recreation | 2018 |
| CRS Shop Limited | Wholesale & retail | 2022 |
| Crystalgalore Ltd | Wholesale & retail | 2025 |
| CSC Capital Limited | Financial services | 2021 |
| CSM Plumbing and Heating Ltd | Construction | 2021 |
| Cstn Properties Limited | Real estate | 2025 |
| Ctly Limited | Professional & scientific | 2017 |
| Ctvision Hoppr Advertising Ltd | Professional & scientific | 2025 |
| Ctvision Ltd | Professional & scientific | 2024 |
| Culina Limited | Wholesale & retail | 2016 |
| Cursus Limited | Professional & scientific | 2016 |
| Curve Heating Ltd | Construction | 2020 |
| Curve Property Services Ltd | Construction | 2019 |
| CUT Price Wholesale Ltd | Wholesale & retail | 2019 |
| CVM Optimal IT Ltd | Information & communication | 2024 |
| Cybecutive Ltd | Information & communication | 2025 |
| Cyber Synergy Limited | Information & communication | 2011 |
| Cyber Traders Limited | Wholesale & retail | 2023 |
| Cybermarks Ltd | Information & communication | 2020 |
| D Byers Builders Limited | Construction | 2015 |
| D Kneale Associates Limited | Professional & scientific | 2002 |
| D M F Electrical Ltd | Construction | 2018 |
| D Woodfall EYE Care Centre Ltd | Wholesale & retail | 2017 |
| D&D Autocars Limited | Wholesale & retail | 2022 |
| D'Smash Ltd | Hospitality | 2023 |
| D.A.D Services Limited | Health & social care | 2016 |
| D.B. Decorators London Ltd | Construction | 2023 |
| D.K.B. Haulage Ltd | | 2008 |
| D.O.J. Property Solutions Ltd | Real estate | 2025 |
| DAC UK Investments Limited | Real estate | 2024 |
| Daci Builders Ltd | Construction | 2023 |
| DAD Construction Ltd | Construction | 2025 |
| DAD Imprinted Concrete Ltd | Manufacturing | 2019 |
| DAL Field Services Limited | Administrative & support | 2026 |
| Dalefield Construction Limited | Administrative & support | 2020 |
| Dalir Consulting Limited | Information & communication | 2023 |
| Dallas Chicken & Pizza Ltd | Hospitality | 2016 |
| Dallas Chicken and Ribs Limited | Hospitality | 1996 |
| Dallas Distribution Ltd | Wholesale & retail | 2021 |
| Dallas Homes Ltd | Real estate | 2003 |
| Dallas Properties Ltd | Administrative & support | 2016 |
| Damaziofa Investments Limited | Health & social care | 2014 |
| Damtamin Limited | Wholesale & retail | 2012 |
| Damyres Ltd | Construction | 2016 |
| Danes Camp Training Academy Ltd | Health & social care | 2020 |
| Dani GAS Services Ltd | Other services | 2025 |
| Dani INT Ltd | Transport & logistics | 2022 |
| Danial Foods Ltd. | Hospitality | 2021 |
| Danial Motors Ltd | Wholesale & retail | 2021 |
| Daniel L Bukenya Limited | Transport & logistics | 2025 |
| Daniel's Specialists Ltd | Construction | 2019 |
| Dans Builders Ltd | Construction | 2024 |