| C&C Property Solutions Ltd | Real estate | 2025 |
| C&D Residential Estates Ltd | Real estate | 2023 |
| C&G Partners Limited | Real estate | 2024 |
| C&N Film SET and Rigging Ltd | Construction | 2024 |
| C&S Emporium Limited | Wholesale & retail | 2023 |
| C&S Group South Ltd | Construction | 2023 |
| C. Bavington Limited | Administrative & support | 2012 |
| C.A Investments London UK Limited | Real estate | 2018 |
| C.A.S.H. Scaffolding Limited | Construction | 2008 |
| C.L.B. Consulting Solutions Limited | Information & communication | 2018 |
| C.M.J. Properties Limited | Real estate | 1999 |
| C.P.D.O. Limited | Health & social care | 1998 |
| C.S. Commercial Repairs Limited | Wholesale & retail | 2019 |
| C.S.F Collective Ltd | Financial services | 2017 |
| C2E2FC Ltd | Transport & logistics | 2025 |
| C3JS Ltd | Wholesale & retail | 2020 |
| CA Accounting Solutions Ltd | Professional & scientific | 2010 |
| CA Consultancies Limited | Real estate | 2023 |
| CA Developments London Ltd | Real estate | 2022 |
| Caas ANA Global Ltd | Manufacturing | 2023 |
| Cablinks Establishments Limited | Wholesale & retail | 2025 |
| Cabp Holdings Limited | Real estate | 2025 |
| Cadcal Plumbing Limited | Construction | 2024 |
| Cadeb Holdings Ltd | Professional & scientific | 2017 |
| Caela London Ltd | Manufacturing | 2026 |
| Cafe Events on the Marshes Ltd | Hospitality | 2019 |
| Cafe Mona Lisa Ltd | Hospitality | 2025 |
| Caffe in Limited | Hospitality | 2002 |
| Caffeine Culture Ltd | Hospitality | 2026 |
| Café Palestina C.I.C. | Other services | 2017 |
| Caico Limited | Other services | 2014 |
| Cala Casa Property Limited | Real estate | 2022 |
| Calahans Cleaning Services Limited | Administrative & support | 2013 |
| Calashock Ltd | Professional & scientific | 2018 |
| Calculus Recruitment Limited | Administrative & support | 2007 |
| Caledonian Property Management Ltd | Administrative & support | 2009 |
| Call & Hire Ltd | Other services | 2016 |
| Calldnet Telecom Limited | Information & communication | 2022 |
| Callisto Projects Ltd | Construction | 2001 |
| Calma Management Ltd | Professional & scientific | 2015 |
| Calvin UK Limited | Wholesale & retail | 2020 |
| CAM Land (Dursley) Limited | Financial services | 2016 |
| Camas Investments Limited | Financial services | 2024 |
| Camb Barbers Ltd | Other services | 2023 |
| Camber Morris Ltd | Administrative & support | 2025 |
| Cambit Capital Ltd | Financial services | 2026 |
| Cambium Management Services Limited | Other services | 2005 |
| Cambridge Kings Ltd | Construction | 2019 |
| Camden Road Ltd | Real estate | 2021 |
| Camellia Trading Limited | Hospitality | 2011 |
| Cameo Productions Limited | Professional & scientific | 1996 |
| Cameron & Balla Contractors Ltd | Construction | 2016 |
| Cameron Close Management Ltd | Households | 1998 |
| Camoxis Therapeutics Limited | Professional & scientific | 2023 |
| Campaign IT Limited | Administrative & support | 2012 |
| Campana Court Limited | Households | 1998 |
| Campaspe Limited | Financial services | 2006 |
| Campbell HR Consulting Ltd | Administrative & support | 2025 |
| Campbell Investments (UK) Ltd | Wholesale & retail | 2015 |
| Campbell Knightsbridge Ltd | Real estate | 2022 |
| Campbell Mayfair Ltd | Real estate | 2021 |
| Campbell Property & Hospitality Ltd | Hospitality | 2021 |
| Campden Gallery Limited | Arts & recreation | 2003 |
| Canary Wharf Health Limited | Health & social care | 2002 |
| Cancer Care Parcel Ltd | Wholesale & retail | 2022 |
| Cancibra Productions Limited | Construction | 2010 |
| Cando Estate Ltd | Real estate | 2022 |
| Canning Developments London (UK) Limited | Construction | 2023 |
| Cannonquest Limited | | 1976 |
| Canoepy Technology Ltd | Information & communication | 2026 |
| Canonbury Mews Residents' Association Management Company Limited | Real estate | 2005 |
| Canopus Property Developments Limited | Construction | 2025 |
| Canterbury House WD24 RTM Company Limited | Households | 2025 |
| Capacity Ltd | Professional & scientific | 2019 |
| Capcoin Investments Ltd | Real estate | 2017 |
| Capital Consultancy Limited | Information & communication | 2012 |
| Capital Roofing & Building Ltd | Construction | 2026 |
| Capital Wars Publications Limited | Information & communication | 2024 |
| Capoliveri Ltd | Professional & scientific | 2015 |
| Capowillians Limited | Other services | 2020 |
| Capricorn 13 Limited | Other services | 2013 |
| Capricorn Pharma Limited | Professional & scientific | 2011 |
| Capstone Global Advisory Limited | Information & communication | 2026 |
| Capsy Developments Limited | Construction | 2019 |
| Captivate Media Limited | Information & communication | 2016 |
| Car Hire 66 Ltd | Administrative & support | 2017 |
| Caralex Ltd | Real estate | 2024 |
| Caramel Global Limited | Administrative & support | 2016 |
| Caramel Global Trade Limited | Administrative & support | 2022 |
| Caramel International Limited | Wholesale & retail | 2007 |
| Carbon Arts and Crafts Limited | Manufacturing | 2020 |
| Carbon Neutral Network Ltd | Extraterritorial | 2006 |
| Cardi Capital Limited | Real estate | 2023 |
| Cardi Consultancy Limited | Professional & scientific | 2026 |
| Cardini Ltd | Professional & scientific | 2024 |
| Care Children Ltd | Health & social care | 2014 |
| Careducation Trust Ltd | Health & social care | 1998 |
| Career Aspects Private Limited | Education | 2016 |
| Career Impact Limited | Information & communication | 2025 |
| Carefree Investments Limited | Real estate | 2002 |