| Crown Pro Elite Ltd | Arts & recreation | 2026 |
| Crown Procurement Services Limited | Wholesale & retail | 2017 |
| Crown Property Services UK Ltd | Real estate | 2006 |
| Crown Remarkable Limited | Wholesale & retail | 2020 |
| Crownlet Ltd | Households | 2025 |
| Croydon Recycling Group Limited | Construction | 2025 |
| CRP Entertainment Ltd | Arts & recreation | 2023 |
| CRT Services (Kent) Limited | Transport & logistics | 2012 |
| CRU London Limited | Administrative & support | 2013 |
| Crusty Corner Ltd | Hospitality | 2003 |
| Cryotron Consultancy Limited | Professional & scientific | 2014 |
| Cryptic Consultancy Limited | Information & communication | 2018 |
| Crystal Charged Ltd | Wholesale & retail | 2022 |
| Crystal Clear Bookkeeping Ltd | Professional & scientific | 2024 |
| Crystal Oral Health Ltd | Health & social care | 2014 |
| Crystal Thorpe Ltd | Health & social care | 2009 |
| Crystals at Dawn Limited | Wholesale & retail | 2026 |
| CS Kent Construction Limited | Construction | 2018 |
| CS Tax Consultancy Ltd | Professional & scientific | 2025 |
| CSG Northern Ltd | Water & waste | 2017 |
| Cskd Ltd | Financial services | 2025 |
| CSL Fire and Security Ltd | Administrative & support | 2019 |
| CSQ Business Solutions Ltd | Professional & scientific | 2016 |
| CT Partners Group Ltd | Information & communication | 2021 |
| CTA Academy Limited | Education | 2025 |
| CTA Projects Ltd | Education | 2023 |
| CTG Fitness Limited | Arts & recreation | 2023 |
| CTI Dominion Capital Ltd | Financial services | 2026 |
| CTL Construction Limited | Construction | 2025 |
| CTL Europe Ltd | Administrative & support | 2017 |
| CTR Property Services Limited | Real estate | 2008 |
| CTR Recycling Ltd | Transport & logistics | 2017 |
| CTS Services Ltd | Wholesale & retail | 1995 |
| CTW Distributions Co., Limited | Wholesale & retail | 2017 |
| Cuddeford Car Services Ltd | Transport & logistics | 2022 |
| Cuddlecity Aesthetics Ltd | Health & social care | 2026 |
| Cuddles Ltd. | Education | 2011 |
| Cudeckmed Services Ltd | Health & social care | 2024 |
| Culinary Delight Limited | Wholesale & retail | 2026 |
| Cumulus IT Ltd | Information & communication | 2024 |
| Cunningham Services(Essex) Ltd | Construction | 2017 |
| Cupid Installations Limited | Other services | 2019 |
| Curamus Maxime Ltd | Information & communication | 2014 |
| Curb Records Limited | Manufacturing | 1999 |
| Curiouser and Curiouser Limited | Professional & scientific | 2025 |
| Currencies 4 YOU Limited | Administrative & support | 2009 |
| Currency Counters Ltd | Education | 2012 |
| Curtis Holt Limited | Professional & scientific | 2003 |
| Curtle UK Limited | Professional & scientific | 2025 |
| Curve Electrical Ltd | Construction | 2025 |
| Custodiandc Limited | Information & communication | 2011 |
| Custom Made Suits Ltd | Wholesale & retail | 2025 |
| Custom Signs and Print Limited | Manufacturing | 2022 |
| Cutbill,King & Company Limited | Financial services | 1956 |
| CVP Dennis Ltd | Construction | 2022 |
| Cwcarpentry Ltd | Construction | 2020 |
| CWD Transport Ltd | Education | 2020 |
| D & D Roofing & Building Ltd | Construction | 2025 |
| D & D Surfacing Ltd | Construction | 2016 |
| D & E West Limited | Real estate | 2018 |
| D & L Traders Ltd | Wholesale & retail | 2024 |
| D & M Building & Fabric Ltd | Construction | 2025 |
| D & M Corporate Ltd | Other services | 2025 |
| D & M Electrical (2025) Ltd | Construction | 2025 |
| D & M Joinery Ltd | Construction | 2025 |
| D & M Mechanical Ltd | Construction | 2023 |
| D & M Plumbing and Heating Solutions Ltd | Construction | 2019 |
| D & M Properties (2025) Ltd | Real estate | 2025 |
| D & M Services (South ) Ltd | Construction | 2026 |
| D & O Electrical Services Ltd | Construction | 2023 |
| D & R Business Services Limited | Real estate | 2025 |
| D & R Jointing Services Ltd | Construction | 2001 |
| D & S West Limited | Real estate | 2018 |
| D a C Vehicle Repairs Limited | Wholesale & retail | 2002 |
| D a Compliance Ltd | Other services | 2018 |
| D and M Lewis Limited | Real estate | 2015 |
| D C Services and Welding Ltd | Wholesale & retail | 2018 |
| D Hammond (Holdings) Limited | Financial services | 2015 |
| D Hammond Construction Limited | Construction | 2021 |
| D Hammond Group EOT Limited | Administrative & support | 2023 |
| D Hammond Group Limited | Financial services | 2015 |
| D Hammond Limited | Construction | 2001 |
| D Hammond Services Limited | Financial services | 2023 |
| D J Boxall Building & Decorating Services Limited | Construction | 2000 |
| D L V Consulting Limited | Administrative & support | 2014 |
| D Lambert Property Services Ltd | Construction | 2022 |
| D M Flooring Contractors Limited | Construction | 2008 |
| D N Haulage Ltd | Transport & logistics | 2001 |
| D S G Invest Limited | Extraterritorial | 2020 |
| D Solutions Group Limited | Information & communication | 2019 |
| D Twin Properties Limited | Real estate | 2023 |
| D&B Groundwork Ltd | Construction | 2025 |
| D&D DRY Lining Ltd | Construction | 2023 |
| D&E Events Limited | Information & communication | 2017 |
| D&P Electrical Installations Limited | Manufacturing | 2010 |
| D&R Jointing Services EOT Limited | Professional & scientific | 2022 |
| D. a. Kelmar Projects Limited | Construction | 1987 |
| D.B.T. (Holdings) Limited | Real estate | 1972 |
| D.K Lift Services Limited | Manufacturing | 2017 |
| D2 Drive Ltd | Education | 2012 |