| CAP Waste Limited | Water & waste | 2014 |
| Capital Gainz Ltd | Real estate | 2020 |
| Capital Property & Development Limited | Construction | 2013 |
| Capital Property Maintenance Holdings Limited | Financial services | 2021 |
| Capital Property Maintenance Limited | Administrative & support | 2010 |
| Capital Removals Limited | Transport & logistics | 2019 |
| Capital Square Holding Company Ltd | Real estate | 2019 |
| Capitaldirect&Co Ltd | Hospitality | 2015 |
| Capitata Limited | Administrative & support | 2014 |
| Capitol Facilities & Support Services Limited | Administrative & support | 2013 |
| Capitol Facilities Management Limited | Administrative & support | 2025 |
| Capitol Floor & Hygiene Maintenance Limited | Administrative & support | 2011 |
| Capitol Group Holdings Limited | Financial services | 2024 |
| Capture Photo Studio Limited | Other services | 2017 |
| Carbon Evaluations Limited | Information & communication | 2011 |
| Carbon Industries Holdings Limited | Professional & scientific | 2003 |
| Carbon-Wise Consulting Limited | Professional & scientific | 2023 |
| Cardak Limited | Hospitality | 2017 |
| Cardhouse Properties Ltd | Hospitality | 2018 |
| Cardova Limited | Professional & scientific | 2014 |
| Cardwell News Limited | Wholesale & retail | 2024 |
| Care Pharma (Romford) Ltd | Health & social care | 2012 |
| Careland Healthcare Services Ltd | Administrative & support | 2019 |
| Carepath Health Ltd | Health & social care | 2023 |
| Caribbean Bites Ltd | Hospitality | 2015 |
| Caring Angels of London Ltd | Transport & logistics | 2026 |
| Carmel GPN Ltd | Education | 2024 |
| Carnarvon Group Limited | Financial services | 2018 |
| Carnarvon Hotels Limited | Hospitality | 1967 |
| Carolina Grove Consulting Limited | Professional & scientific | 2023 |
| Carryon Construction Limited | Construction | 2016 |
| Cars Hunt Ltd | Wholesale & retail | 2013 |
| Carsual Limited | Wholesale & retail | 2013 |
| Casa Moon Properties LLP | | 2025 |
| Caseguard Limited | Information & communication | 2025 |
| Cassandra Crouch Garden Design Limited | Administrative & support | 2015 |
| Castle Containers Limited | Transport & logistics | 2025 |
| Castle Gibson Limited | Wholesale & retail | 2000 |
| Castlehaven Group Limited | Real estate | 2002 |
| Caterham Estates Ltd | Real estate | 2021 |
| Caterin Investments Ltd | Manufacturing | 2011 |
| Catherine Asta Consulting Ltd | Professional & scientific | 2023 |
| Catsis Enterprise Ltd | Construction | 2019 |
| Caxton Property Services London Limited | Real estate | 2014 |
| Cayan Binayah Real Estate Ltd | Construction | 2016 |
| CB Goodmayes Limited | Construction | 2016 |
| CC Expert Ltd | Construction | 2024 |
| CC Promotions Limited | Arts & recreation | 2019 |
| Ccmv Ltd | Arts & recreation | 2022 |
| CD Fund CIC | Administrative & support | 2024 |
| CD Pearls Limited | Manufacturing | 2019 |
| CD Sports Horses Ltd | Arts & recreation | 2024 |
| CDP Property Holdings Ltd | Real estate | 2024 |
| CDP Property Solutions Ltd | Hospitality | 2016 |
| CEA Systems Limited | Administrative & support | 2004 |
| Ceadar Holdings Limited | Financial services | 2024 |
| Cecelia Frank Ltd | Wholesale & retail | 2016 |
| CED Business Solutions Limited | Administrative & support | 2019 |
| Celau Ltd | Construction | 2025 |
| Celeb Agents Limited | Administrative & support | 2010 |
| Celebrity PR Limited | Arts & recreation | 2005 |
| Celoper Limited | Information & communication | 2016 |
| Celtrik Solutions Limited | Information & communication | 2022 |
| Centenary Field Limited | Arts & recreation | 2025 |
| Central 25 Management Limited | Households | 2008 |
| Central Recruitment Limited | Information & communication | 2021 |
| Centralogic Limited | Information & communication | 2011 |
| Centramed AI Limited | Information & communication | 2025 |
| Centrum Health Care Limited | Health & social care | 2024 |
| Cenuse Trans Ltd | Transport & logistics | 2018 |
| CEO Consult Ltd | Information & communication | 2015 |
| Certobrit Ltd | Professional & scientific | 2025 |
| CEW Search Limited | Administrative & support | 2024 |
| Ceyo London Limited | Hospitality | 2025 |
| CG Corporate Ltd | Wholesale & retail | 2022 |
| CG Electrical Systems Ltd | Construction | 2025 |
| CGC Rigging & Scaffolding Services Ltd | Information & communication | 2015 |
| CGP Solutions Ltd | Real estate | 2023 |
| CH Equity Partners Ltd | Real estate | 2024 |
| Chainpoint Ltd | Wholesale & retail | 2025 |
| Chalkhill Maintenance Ltd | Households | 2022 |
| Chalkhill Property Management Ltd | Households | 2024 |
| Chalkney Meadow Management Company Ltd | Households | 2021 |
| Chalkway Property Limited | Real estate | 2023 |
| Chalmers Business Consulting Limited | Administrative & support | 2014 |
| Chamberlain & Thelwell (Holdings) Limited | Financial services | 1999 |
| Chamberlain and Thelwell Limited | Wholesale & retail | 1947 |
| Champagne Problems LDN Ltd | Wholesale & retail | 2026 |
| Chandi 62 Limited | Real estate | 2021 |
| Chandler King (City) Limited | Financial services | 1998 |
| Change Thread Ltd | Information & communication | 2015 |
| Chantrun Limited | Hospitality | 1997 |
| Charalambous Properties Ltd | Real estate | 2022 |
| Chariots Motorhomes Limited | Wholesale & retail | 2000 |
| Charles Benoliel Consulting Ltd | Administrative & support | 2023 |
| Charles Edward Rose Limited | Real estate | 2026 |
| Charlie Browns MOT Centre Limited | Wholesale & retail | 2018 |
| Charsi Karahi Limited | Hospitality | 2016 |
| Charterstar Limited | Real estate | 2006 |
| Chartingforprofit Limited | Financial services | 2012 |