| Carefree Trading Limited | Real estate | 2002 |
| Carham Advisors Ltd | Professional & scientific | 2012 |
| Cariad the COW Ltd | Arts & recreation | 2024 |
| Caring for Kids Limited | Other services | 2006 |
| Carita Services Limited | Wholesale & retail | 2015 |
| Carletto's UK Ltd | Transport & logistics | 2021 |
| Carlovers Ltd | Administrative & support | 2018 |
| Carlton Capital Limited | Administrative & support | 2016 |
| Carlton Commercial Investments Limited | Real estate | 2017 |
| Carlton Land Developments Limited | Real estate | 2017 |
| Carlton Property Group Limited | Extraterritorial | 2016 |
| Carlton Property Partnership Limited | Real estate | 2024 |
| Carlyle Lodge Management Company Limited | Real estate | 1990 |
| Carmona Consultants Limited | Administrative & support | 2012 |
| Carpenters Place (Whetstone) Management Company Limited | Households | 2003 |
| Carpet Cleaning Wizards Limited | Administrative & support | 2024 |
| Carr Mitchell Limited | Financial services | 2009 |
| Carroll Management Ltd | Construction | 2014 |
| Carthamon Ltd | Households | 2020 |
| Cartlidge Levene Investments Limited | Other services | 1987 |
| Cartwrights Accountants Ltd | Professional & scientific | 2020 |
| Cartwrights Audit Limited | Professional & scientific | 2001 |
| Casa Blanca Property Group Limited | Construction | 2022 |
| Casa N London Ltd | Wholesale & retail | 2014 |
| CASA2C Ltd | Professional & scientific | 2022 |
| Cascara Gourmet Ltd | Wholesale & retail | 2020 |
| Casey Key Properties Ltd | Real estate | 2011 |
| Cassa Studios Ltd | Professional & scientific | 2024 |
| Cassi One Limited | Information & communication | 2025 |
| Cassino Shoes Ltd | Wholesale & retail | 2025 |
| Cassis Property Services Ltd | Real estate | 2024 |
| Castalia Developments Limited | Construction | 2013 |
| Casterbridge Investments Ltd | Real estate | 2022 |
| Castle Combe Film Locations Limited | Administrative & support | 2026 |
| Castor Services Ltd | Construction | 2019 |
| Catalyse Consultants Limited | Information & communication | 2017 |
| Catalyst Consultants Limited | Administrative & support | 2014 |
| Category Compass Ltd | Other services | 2012 |
| Caterers (Dalston) Limited | Real estate | 1964 |
| Catherine Cheung Piano Studio Ltd | Education | 2024 |
| Catherine Devereux Ltd | Health & social care | 2012 |
| Catterall Enterprises Limited | Information & communication | 2026 |
| Cattley Close Management Company (Barnet) Limited | Households | 1995 |
| Catwalk Pets & Aquatics Limited | Wholesale & retail | 2014 |
| Causeway Flats Freehold Limited | Real estate | 2004 |
| Causeway Flats Residents Association Limited | Households | 1965 |
| Caushi Construction Ltd | Construction | 2021 |
| Cave for MEN Limited | Other services | 2018 |
| Cavendo Holdings Ltd | Construction | 2018 |
| Cavendo Homes (Cuffley) Ltd | Construction | 2017 |
| Cavendo Ltd | Construction | 2019 |
| Caya Limited | Administrative & support | 2026 |
| CBD (South) Ltd | Construction | 2018 |
| CBD Plus UK Ltd | Wholesale & retail | 2019 |
| CBM Commercial Ltd | Real estate | 2019 |
| CBS Barbers Ltd | Other services | 2019 |
| CBT London Ltd | Health & social care | 2015 |
| CC Consultancy Services and Concierge Limited | Professional & scientific | 2024 |
| CC Estates Limited | Real estate | 2026 |
| CC Investment & Development Company Ltd | Real estate | 2017 |
| CC Racing Limited | Administrative & support | 2024 |
| Cccs London Limited | Administrative & support | 2014 |
| Ccga Consulting Ltd | Administrative & support | 2014 |
| CDD Property Services Limited | Real estate | 2016 |
| CDG Facades Ltd | Construction | 2025 |
| CDK Property Ltd | Real estate | 2021 |
| Cdkg Limited | Hospitality | 2012 |
| Cdlc Limited | Construction | 2017 |
| CDN Squared Limited | Information & communication | 2021 |
| Ceaa Ltd | Real estate | 2020 |
| Cecef Limited | Health & social care | 2022 |
| Cecil Properties Limited | Real estate | 2007 |
| Cedar House Financial Services Limited | Financial services | 1986 |
| Cedar House Holdco Limited | Financial services | 2025 |
| Cedarwood Family Estates Limited | Real estate | 2026 |
| Celiks' Mensroom Limited | Other services | 2007 |
| Cellular U.K. Limited | Information & communication | 1994 |
| Celpart Ltd | Real estate | 2011 |
| Centanni Fine Food Ltd | Wholesale & retail | 2022 |
| Centauri Property Limited | Real estate | 2022 |
| Centaurus Property Investments Limited | Real estate | 2022 |
| Centigra Investments Limited | Real estate | 2019 |
| Centigra Limited | Information & communication | 2004 |
| Centorian Limited | Real estate | 2020 |
| Central Developments (UK) Limited | Construction | 2001 |
| Central Europe Trust Company Limited | Professional & scientific | 1989 |
| Central Land Investments Ltd | Professional & scientific | 2011 |
| Central Quick Stop Ltd | Wholesale & retail | 2017 |
| Centre of Arabic and Islamic Arts Ltd | Arts & recreation | 2023 |
| Centre Spot Entertainment Limited | Information & communication | 2023 |
| Centrique Enterprises Limited | Administrative & support | 2015 |
| Centrique Residential Limited | Administrative & support | 2026 |
| Century Maintenance Ltd | Construction | 2024 |
| Certified Sports Limited | Wholesale & retail | 2012 |
| Certifiedmotorsuk Limited | Wholesale & retail | 2026 |
| Cervantes Energy Ltd | Professional & scientific | 2010 |
| CET Advisors Limited | Professional & scientific | 2006 |
| CET Research Limited | Administrative & support | 2014 |
| Cetus Property Investments Limited | Real estate | 2023 |
| CEYLAN46 Ltd | Hospitality | 2025 |