| Cruise Cleaning Services Ltd | Administrative & support | 2003 |
| Cryntos Ltd | Information & communication | 2025 |
| Cryptofun Ltd | Education | 2024 |
| Crystal Beauty Services Ltd | Wholesale & retail | 2014 |
| Crystal Clear Traditional Window Cleaning Services Ltd | Administrative & support | 2025 |
| Crystal Jones Consulting Ltd | Professional & scientific | 2026 |
| Crystalclean Carpet Care Ltd | Administrative & support | 2025 |
| Cske Limited | Construction | 2011 |
| CTC Automobile Service Ltd | Wholesale & retail | 2023 |
| CTC E-Commerce Trading Limited | Wholesale & retail | 2025 |
| Ctrl Events Ltd | Administrative & support | 2025 |
| Cube Energies Ltd | Manufacturing | 2025 |
| CUE Sports Crawley Ltd | Hospitality | 2024 |
| CUK Ltd | Information & communication | 2007 |
| Curelo Care Limited | Wholesale & retail | 2025 |
| Curry Fast Food Ltd | Hospitality | 2020 |
| Curry Town Pizza Ltd | Hospitality | 2024 |
| Curve Accountancy Limited | Extraterritorial | 2002 |
| Customised Graphics Ltd | Manufacturing | 2021 |
| Customize Bodyshop Ltd | Administrative & support | 2016 |
| Cv-Player Ltd | Information & communication | 2017 |
| CWE Solutions Ltd | Wholesale & retail | 1999 |
| CYC Chartering Limited | Transport & logistics | 2019 |
| CYC Management Limited | Transport & logistics | 2019 |
| Cygnet Digital Limited | Information & communication | 2018 |
| Cyrus Private Ltd | Wholesale & retail | 2020 |
| CYW Holdings Limited | Financial services | 2024 |
| D & R Prestige Construction Limited | Construction | 2023 |
| D & S Mugridge Limited | Construction | 2019 |
| D & T Property Building Contractors Limited | Construction | 2013 |
| D Back Yard Limited | Hospitality | 2026 |
| D Cooke Limited | Construction | 2017 |
| D Hunt Roofing Limited | Construction | 2002 |
| D M Goddard Consulting Ltd | Professional & scientific | 2025 |
| D Mulroy Limited | Information & communication | 2018 |
| D P Ductwork Ltd | Construction | 2008 |
| D&C Contractors Ltd | Construction | 2025 |
| D&C Haulage Ltd | Transport & logistics | 2019 |
| D&D Coffee and More Limited | Manufacturing | 2019 |
| D&D Cricket Academy Ltd | Education | 2021 |
| D&D Devops Consulting Limited | Information & communication | 2021 |
| D&D Honey UK Ltd | Agriculture & fishing | 2023 |
| D&D Removals & Logistics Ltd | Water & waste | 2025 |
| D&G Vehicle Repairs Ltd | Wholesale & retail | 2025 |
| D&H, Food Ltd | Manufacturing | 2023 |
| D&K Custom Build Limited | Construction | 2023 |
| D&M Services Southern Ltd | Construction | 2013 |
| D&N22 Ltd | Construction | 2022 |
| D-Unique Properties Limited | Real estate | 2022 |
| D.F. Warehouses Limited | Transport & logistics | 1972 |
| D.I.A. (INT.) Limited | Other services | 1983 |
| D.P.R.A. Limited | Households | 1990 |
| D.W. Hart Group Ltd | Financial services | 2026 |
| D124 Ltd | Information & communication | 2023 |
| Daconair Air Conditioning & Building Services Limited | Wholesale & retail | 1990 |
| Daily Dharti Ltd | Information & communication | 2024 |
| Daily Fresh Naan Crawley Ltd | Hospitality | 2025 |
| Dailycartdeals Ltd | Wholesale & retail | 2019 |
| Dale Road Oral Care Ltd | Health & social care | 2010 |
| Daledene (Freehold) Limited | Households | 2021 |
| Dama Studios Ltd | Education | 2021 |
| Damage Doctor Ltd | Construction | 2025 |
| Damalo Limited | Real estate | 1961 |
| Damar Windows LLP | | 2001 |
| Damien Alfred Arthur Morris Ltd | Wholesale & retail | 2025 |
| Damselfly Properties Limited | Real estate | 2024 |
| Dan's Sports DEN Limited | Other services | 2014 |
| Dancehub CIC | Arts & recreation | 2019 |
| Dandelion Training and Development Ltd | Education | 2026 |
| Danelcan Limited | Information & communication | 2018 |
| Dani Aashiana Limited | Real estate | 2024 |
| Daniel Service Mini CAB Ltd | Transport & logistics | 2023 |
| Daniels Flooring Limited | Construction | 2026 |
| Daniels House Ltd | Real estate | 2021 |
| Daniels Real Estate Limited | Real estate | 2001 |
| Daniels Upholstery Limited | Manufacturing | 2012 |
| Danish Group of Companies Limited | Administrative & support | 2023 |
| Danley Group Ltd | Wholesale & retail | 2020 |
| Dansoft Aviation Services Ltd | Manufacturing | 2010 |
| Daolrevo Limited | Information & communication | 2013 |
| Darenotdoubt Ltd | Wholesale & retail | 2025 |
| Dark Arcana Ltd | Wholesale & retail | 2024 |
| Darou Miname & Co Ltd | Administrative & support | 2022 |
| Darryl's Lilypad Ltd | Arts & recreation | 2015 |
| Darshak Ltd | Professional & scientific | 2025 |
| Darshi Beauty Ltd | Other services | 2024 |
| Darshnish Property Ltd | Wholesale & retail | 2018 |
| Dartmoor Unlocked Ltd | Hospitality | 2021 |
| DAS Erste Ltd | Construction | 2020 |
| Dassle Food Limited | Wholesale & retail | 2025 |
| Data & Electrical Services Limited | Construction | 2017 |
| Data Freedom Ltd | Information & communication | 2015 |
| Data Mail Solutions Limited | Manufacturing | 2011 |
| Dataply Limited | Information & communication | 2016 |
| Datesafe Ltd | Manufacturing | 2025 |
| Dats-It Ltd | Administrative & support | 2019 |
| Davdan Care Limited | Health & social care | 2023 |
| Davescardslocal Limited | Wholesale & retail | 2025 |
| David & Vance Properties Ltd | Real estate | 2022 |
| David Delivery Ltd | Transport & logistics | 2021 |