| CSB (UK) Limited | Professional & scientific | 2004 |
| Cslt Group Limited | Administrative & support | 2025 |
| CSP Management Limited | Construction | 2014 |
| CSS Finance Consulting Limited | Professional & scientific | 2024 |
| Cssl Holdings Limited | Financial services | 2017 |
| CT (Pettswood) Ltd | Other services | 2003 |
| Cube 12 Brand and Marketing Limited | Professional & scientific | 2026 |
| Cube Box Limited | Manufacturing | 2024 |
| Cuegle International Holdings Limited | Financial services | 2024 |
| Cuegle Limited | Administrative & support | 2024 |
| Cuell Motion Systems Ltd | Wholesale & retail | 2025 |
| Cuisine Foodservice Ltd | Wholesale & retail | 2026 |
| Culinaaris Limited | Hospitality | 2020 |
| Culverhouse Financial Planning Ltd | Financial services | 2013 |
| Cupid Creative Limited | Other services | 2011 |
| Curated Conversion Ltd | Professional & scientific | 2026 |
| Cure&Cure Ltd | Wholesale & retail | 2023 |
| Curedry Damp Proofing Ltd | Construction | 2025 |
| Curtis Court Freehold Limited | Other services | 2010 |
| Custom Carpets & Floors Limited | Construction | 2018 |
| Custom Influence Ltd | Professional & scientific | 2022 |
| Cutman Construction Ltd | Construction | 2023 |
| CW Coaching and Nutrition Ltd | Other services | 2023 |
| CW Physiotherapy Ltd. | Health & social care | 2022 |
| Cwhp 2 Limited | Extraterritorial | 2024 |
| Cwhp 3 Limited | Extraterritorial | 2024 |
| Cwhp Limited | Wholesale & retail | 2024 |
| CWM Okonji Limited | Health & social care | 2023 |
| Cxellence Ltd | Professional & scientific | 2018 |
| Cybconnect Ltd | Information & communication | 2020 |
| Cyber Theatre Ltd | Information & communication | 2010 |
| Cycle 42 Ltd | Wholesale & retail | 2019 |
| Cygnus Construction Partners Limited | Construction | 2022 |
| Cygnus Developments and Investments Ltd | Administrative & support | 2017 |
| CYK Hair & Beauty Limited | Other services | 2019 |
| Cynsai Limited | Health & social care | 2012 |
| Cywan Ltd | Transport & logistics | 2012 |
| Czorlu Ltd | Hospitality | 2011 |
| D a Gibbons Builders Ltd | Construction | 2014 |
| D Bignell Pipeservices Limited | Construction | 2010 |
| D G Building Restoration Ltd | Construction | 2011 |
| D P O'Brien Limited | Construction | 2009 |
| D R Home Maintenance Limited | Administrative & support | 2015 |
| D RA Group Ltd | Wholesale & retail | 2024 |
| D RA Products Ltd | Manufacturing | 2025 |
| D W Berryman Limited | Construction | 2002 |
| D Woods Plumbing Ltd | Construction | 2017 |
| D&D General Maintenance Ltd | Construction | 2022 |
| D&M Building and Renovations Ltd | Construction | 2024 |
| D&P Property Investments Ltd | Real estate | 2020 |
| D-Structure Civils Limited | Financial services | 2022 |
| D-Structure Limited | Professional & scientific | 2015 |
| D-Way System and Tech Limited | Information & communication | 2017 |
| D.Harshan Limited | Health & social care | 2025 |
| D.J.I.Ricochet Ltd | Manufacturing | 2025 |
| D3 Technology Ltd | Information & communication | 2023 |
| D3DICATED Ltd | Wholesale & retail | 2020 |
| DA and DA Associates Ltd | Construction | 2026 |
| DA Ming Limited | Hospitality | 2025 |
| DA6 Catering Co Ltd | Hospitality | 2023 |
| DAB IT Contracts Limited | Information & communication | 2014 |
| Dadas Healthcare Services Ltd | Administrative & support | 2017 |
| Daijj Ltd | Wholesale & retail | 2019 |
| Dailyshutters Ltd | Manufacturing | 2022 |
| Dainton Lift Services Limited | Construction | 1998 |
| Dajon Data Management Ltd | Administrative & support | 1998 |
| Dajosh Ltd | Professional & scientific | 2015 |
| Dakana Foods Limited | Wholesale & retail | 2014 |
| Dakota London Limited | Construction | 2022 |
| Dakra Projects Ltd | Construction | 2023 |
| Dakshin Ltd | Hospitality | 2018 |
| DAL Solution Ltd | Construction | 2025 |
| Dale Wood Property Group Ltd | Real estate | 2024 |
| Dale Wood Road Management Company Limited | Other services | 1995 |
| Dali Trading Limited | Wholesale & retail | 2015 |
| Dalven Company Limited | Information & communication | 2025 |
| Damaral Ltd | Professional & scientific | 2019 |
| Dame Events Limited | Administrative & support | 2023 |
| Dammy ANN Ltd | Administrative & support | 2024 |
| Dam’Sweet Ltd | Construction | 2021 |
| Dancing to GOD for Healing Ltd | Other services | 2021 |
| Dancy Consulting Ltd | Professional & scientific | 2013 |
| Dandanakka CIC | Education | 2026 |
| Danepark Limited | Households | 1974 |
| Danielle Walker Interior Design Ltd | Professional & scientific | 2022 |
| Danielnabi Ltd | Construction | 2012 |
| Danik Solutions Ltd | Administrative & support | 2024 |
| Dansar Property Investment Ltd | Real estate | 2024 |
| Dapa Building Services Installation Ltd | Construction | 2023 |
| Dapd Property LLP | | 2019 |
| Daphnee Limited | Health & social care | 2022 |
| Dara Jewelry Ltd | Wholesale & retail | 2025 |
| Darent Valley Trout Fishers Limited | Arts & recreation | 2013 |
| Darrick Wood House Management Limited | Households | 1982 |
| Darrick Wood School | Education | 2010 |
| Darwin House Management Company Limited | Households | 2004 |
| Darwin Performance Science Limited | Financial services | 2021 |
| Dash Courier Services Ltd | Transport & logistics | 2017 |
| Dashmesh Infotech PVT Ltd | Information & communication | 2022 |
| Dashmesh PVT Ltd | Real estate | 2021 |