| Campbell Management Enterprise Ltd | Professional & scientific | 2022 |
| Campion&Co Ltd | Arts & recreation | 2025 |
| Candleking Limited | Extraterritorial | 2012 |
| Cape Town Thing UK Ltd | Professional & scientific | 2020 |
| Capesso Strategic Partners Limited | Professional & scientific | 2009 |
| Capital for Business Limited | Professional & scientific | 2015 |
| Capstone Limited | Real estate | 2006 |
| Car Fixxers Ltd | Wholesale & retail | 2025 |
| Cardwell Estates Limited | Administrative & support | 2013 |
| Care in Finance Ltd | Financial services | 2011 |
| Care Response Limited | Health & social care | 2007 |
| Careers in Fitness Limited | Health & social care | 2004 |
| Careers in Ltd | Education | 2006 |
| Cargobox Limited | Transport & logistics | 2025 |
| Carlcon Limited | Real estate | 1997 |
| Carlin Capital Limited | Real estate | 2014 |
| Caroline Barclay Design Ltd | Information & communication | 2018 |
| Caroline Cornish Management Limited | Administrative & support | 2000 |
| Carolyn Mayling Media Ltd | Information & communication | 2026 |
| Carr Williams Lettings Ltd | Real estate | 2012 |
| Carr Williams Limited | Real estate | 2010 |
| Carroll's Yard Apartments Limited | Real estate | 2025 |
| Carroll's Yard Property Management Limited | Households | 2026 |
| Carter Ventures Ltd | Administrative & support | 2022 |
| Cater Design Limited | Administrative & support | 2009 |
| Caterpillar Consulting Ltd | Professional & scientific | 2024 |
| Cavalier City Limited | Wholesale & retail | 1989 |
| Cavres 21 Limited | Other services | 2020 |
| Cawkwell Tiling Ltd | Construction | 2006 |
| CC Option Ltd | Real estate | 2023 |
| Ccap Ltd. | Administrative & support | 2003 |
| Ccgi Ltd | Professional & scientific | 2019 |
| CCI Life Sciences Limited | Professional & scientific | 2024 |
| CD Advisory Services Limited | Other services | 2019 |
| CDA South West Limited | Construction | 2016 |
| CDF Management Limited | Professional & scientific | 2013 |
| Ceda Healthcare Group Limited | Financial services | 2022 |
| Ceda Healthcare Limited | Health & social care | 2018 |
| Cedar Cars (Ascot) Limited | Transport & logistics | 2018 |
| CEI Bont Limited | Financial services | 2017 |
| Celebrasian Limited | Arts & recreation | 2006 |
| Celestria Design Ltd | Information & communication | 2017 |
| Celo Group Ltd | Wholesale & retail | 2012 |
| Cemita Ltd | Hospitality | 2024 |
| Central Procurement Ltd | Professional & scientific | 2024 |
| Centurion Club Limited | Extraterritorial | 2012 |
| Centurion Club Management Ltd | Arts & recreation | 2009 |
| Centurion Golf PLC | Arts & recreation | 2012 |
| CEO Yourself Ltd | Administrative & support | 2026 |
| Cerebroscience Ltd | Administrative & support | 2013 |
| Ceres Capital Ltd | Financial services | 2022 |
| Cerulean Powerboats Limited | Manufacturing | 2021 |
| Cervox Ltd | Professional & scientific | 2025 |
| CG Clareville Grove LLP | | 2017 |
| CH 1 Investment Partners LLP | | 2016 |
| Chak Transport Ltd | Transport & logistics | 2025 |
| Chalycoomb Capital Ltd | Financial services | 2025 |
| Chambers Wealth Financial Planning Limited | Professional & scientific | 2025 |
| Chambers Wealth LLP | | 2022 |
| Champion Talent Limited | Arts & recreation | 2010 |
| Chancery Lane Income Planners Ltd | Financial services | 2019 |
| Chancery Lane Research Ltd | Extraterritorial | 2024 |
| Chaotic Resonance Ltd | Information & communication | 2023 |
| Chapel Hill Denham UK Limited | Financial services | 2021 |
| Charity People Limited | Administrative & support | 1989 |
| Charles Good Ltd | Professional & scientific | 2015 |
| Charlie Horner Design Ltd | Professional & scientific | 2018 |
| Charters Property Management Ltd | Real estate | 2021 |
| Charters School | Education | 2012 |
| Chartwell Computer Systems Limited | Information & communication | 2003 |
| Chartwood Properties Limited | Hospitality | 2025 |
| Chase TV Limited | Information & communication | 2006 |
| Check Your Facts Ltd | Administrative & support | 2019 |
| Chefskit Limited | Wholesale & retail | 2012 |
| Cherry Blossom Gate Ltd | Construction | 2018 |
| Children's Hearts UK | Health & social care | 2007 |
| Chilled Chilli Ltd | Information & communication | 2019 |
| Chilli Chat Limited | Hospitality | 2025 |
| Chiswick Estates Freehold Limited | Real estate | 2023 |
| Chiswick Estates Limited | Construction | 2011 |
| Chobham Road Investments Limited | Financial services | 2016 |
| Chris Reid Data Consultancy Ltd | Information & communication | 2024 |
| Christine Martin Consults Ltd | Professional & scientific | 2023 |
| Church Road Garage Limited | Real estate | 1993 |
| Church View Boundary Street Limited | Households | 1999 |
| Church Wing Investments Ltd | Financial services | 2024 |
| Churchill Applied Biotechnology Limited | Professional & scientific | 1987 |
| Cidak Auto Parts Ltd | Wholesale & retail | 2020 |
| Circle Gallery Limited | Wholesale & retail | 1998 |
| CIS Street Furniture Limited | Manufacturing | 1995 |
| Cissbury Capital Ltd | Financial services | 2022 |
| Cite Distribution LLP | | 2015 |
| CJ Blueprints LLP | | 2025 |
| CJ London Hair Ltd | Wholesale & retail | 2023 |
| Claires Court Schools Limited | Education | 1998 |
| Clareville Grove Capital Limited | Professional & scientific | 2017 |
| Clarewood Consulting Limited | Information & communication | 2002 |
| Classic Collectables Limited | Wholesale & retail | 2018 |
| Clasto Ltd | Professional & scientific | 2020 |
| Clayholes Holdings Limited | Financial services | 2025 |