| CRD Building Ltd | Construction | 2023 |
| CRE8BYIDIOT Ltd | Wholesale & retail | 2018 |
| Create Courier Limited | Information & communication | 2024 |
| Creative Arts Centre of Excellence Limited | Arts & recreation | 2016 |
| Creative Concepts Training Limited | Professional & scientific | 2007 |
| Creative Imagination Studios Ltd | Arts & recreation | 2024 |
| Creatorkey Limited | Other services | 2025 |
| Credence Collective Limited | Wholesale & retail | 2025 |
| Credit and Finance Ltd | Administrative & support | 2008 |
| Crest IT Services Ltd | Information & communication | 2011 |
| Crewsonic Ltd | Administrative & support | 2026 |
| Crewswell Limited | Real estate | 2016 |
| Creyo Ltd | Wholesale & retail | 2022 |
| CRG OPS (UK) Ltd | Other services | 2026 |
| Cribo International Ltd | Information & communication | 2023 |
| Cricket@Trader Ltd | Arts & recreation | 2022 |
| Cricklewood Construction Ltd | Construction | 2022 |
| Cricklewood Wanderers C.I.C. | Education | 2021 |
| Crispies Whitehall Ltd | Wholesale & retail | 2022 |
| Crispy Culture Ltd | Wholesale & retail | 2025 |
| Cristian & Monica Ltd | Construction | 2018 |
| Cristof Enterprise Ltd | Construction | 2018 |
| Critical Security Services Limited | Administrative & support | 2017 |
| Croft Homes (Wembley) Ltd | Real estate | 2018 |
| Cronin Services Ltd | Construction | 2015 |
| Crossbird Limited | Wholesale & retail | 2013 |
| Crossover Care Services Ltd | Health & social care | 2022 |
| Crowmc (Neasden) Limited | Construction | 2012 |
| Crowmcc (Maida Vale) Limited | Construction | 2014 |
| Crowmcc (Woodfield Road) Limited | Construction | 2013 |
| Crown Clean London Ltd | Administrative & support | 2025 |
| Crown Greetings (Europe) Ltd | Wholesale & retail | 2026 |
| Crown Tours Ltd | Administrative & support | 2025 |
| Crown Vehicle Management Limited | Administrative & support | 2011 |
| Crown Walk Ventures Limited | Construction | 2026 |
| Crowndale Properties Limited | Real estate | 2007 |
| Crownhill Glass Limited | Construction | 1976 |
| Crownstone Devlopments Limited | Construction | 2026 |
| Crownwell Estates Limited | Real estate | 2025 |
| Croydon Court Management Company Limited | Administrative & support | 1999 |
| CRS Creative Limited | Administrative & support | 2022 |
| CRW (UK) Ltd. | Wholesale & retail | 2001 |
| Crystal Wembley Ltd | Hospitality | 2016 |
| Crystal Appreal Ltd | Wholesale & retail | 2024 |
| Crystal Bites London Ltd | Hospitality | 2026 |
| Crystal Bites Ltd | Hospitality | 2025 |
| Crystal Cleaning CLA Ltd | Construction | 2025 |
| Crystal Crown Ltd | Manufacturing | 2011 |
| Crystal Food and Wine Limited | Wholesale & retail | 2017 |
| Crystal News Limited | Wholesale & retail | 2005 |
| Crystal Raccoon Limited | Professional & scientific | 2024 |
| Crystalguards Ltd | Financial services | 2018 |
| Crystaline Solutions Limited | Information & communication | 2011 |
| Crystalluxebathrooms Limited | Wholesale & retail | 2026 |
| Crystalpoint Consultancy Limited | Administrative & support | 2017 |
| Crystals R US Limited | Manufacturing | 2006 |
| Cry’S Paving Limited | Other services | 2025 |
| CS Halai Limited | Real estate | 2022 |
| CT Flooring Ltd | Construction | 2025 |
| CT Properties (2023) Ltd | Real estate | 2023 |
| CTJ Living Ltd | Health & social care | 2021 |
| CTN (Retail) Public Limited Company | | 1986 |
| CTN (UK) Limited | | 1985 |
| Ctrl Waterloo Ltd | Other services | 2016 |
| Ctrye Capital Limited | Real estate | 2021 |
| Cube 20 Limited | Real estate | 2023 |
| Cubenetics Limited | Information & communication | 2010 |
| Cubic Estates Ltd | Real estate | 2024 |
| CUE the Light Academy Ltd | Arts & recreation | 2025 |
| Culham Private Hire Limited | Other services | 2017 |
| Culnary Compass Ltd | Administrative & support | 2025 |
| Culture Shock & Co. Limited | Wholesale & retail | 2020 |
| Cumulus International Services Limited | Financial services | 2017 |
| Cuppachai Limited | Hospitality | 2022 |
| Cuppacoff Limited | Hospitality | 2006 |
| Cuppacoff SC Limited | Hospitality | 2014 |
| Curemover Limited | Manufacturing | 2026 |
| Curo Management Ltd | Real estate | 2025 |
| Curolife Biochem Limited | Manufacturing | 2021 |
| Curolife Limited | Construction | 2022 |
| Curtain Road Ltd | Hospitality | 2023 |
| Customerschoice Limited | Wholesale & retail | 2020 |
| Cute Hijab Limited | Wholesale & retail | 2023 |
| CV JOB Recruitment Limited | Administrative & support | 2024 |
| CVL Consultants Ltd | Professional & scientific | 2023 |
| CVS Brent | Professional & scientific | 2011 |
| CWD Projects (Park Works) Limited | Construction | 2014 |
| CX Story Global Ltd | Professional & scientific | 2024 |
| CX Story Ltd | Professional & scientific | 2023 |
| CXI Love Food Ltd | Manufacturing | 2022 |
| CXI Social Ltd | Hospitality | 2026 |
| Cyberdrive Security Ltd | Professional & scientific | 2024 |
| Cyberfy Ltd | Information & communication | 2026 |
| Cybergrid Ltd | Professional & scientific | 2024 |
| Cyberpayroll Ltd | Professional & scientific | 2024 |
| Cybersecs.Biz Ltd | Administrative & support | 2009 |
| Cybertanius Ltd | Information & communication | 2026 |
| Cyclopean Ltd | Extraterritorial | 2018 |
| Cygnoverse Ltd | Information & communication | 2025 |
| Cyjp Limited | Real estate | 2017 |