| Croydex Group Limited | Professional & scientific | 2006 |
| Croydex Limited | Manufacturing | 1995 |
| Cruyfflab UK Ltd. | Wholesale & retail | 2020 |
| Crystal House Platinum Limited | Health & social care | 2013 |
| Csmm Holdings Limited | Real estate | 2017 |
| CTB Trading Platform Limited | Financial services | 2024 |
| Ctfd Holdings Ltd | Financial services | 2026 |
| CTL Homecare Limited | Health & social care | 2026 |
| Ctmr Medical Limited | Health & social care | 2026 |
| Cube Solar Installations Limited | Construction | 2024 |
| Cumber Lane Partnerships Ltd | Construction | 2015 |
| Curated Beverages UK Ltd | Wholesale & retail | 2020 |
| Curbishley Developments Limited | Extraterritorial | 1998 |
| Currie Surgery Limited | Health & social care | 2024 |
| Curvecone Limited | Real estate | 1996 |
| Custometry Ltd | Manufacturing | 2021 |
| Customs Compliance Limited | Professional & scientific | 2013 |
| Cusworth Master Locksmiths Limited | Construction | 2007 |
| CVR Automotive Limited | Wholesale & retail | 2017 |
| CW Leisure Limited | Administrative & support | 2017 |
| Cwad Developments Limited | Construction | 2021 |
| Cwea Consulting Limited | Health & social care | 2019 |
| CWF (2013) Limited | Extraterritorial | 2013 |
| CY NG Limited | Health & social care | 2013 |
| Cyber Kings Limited | Wholesale & retail | 2025 |
| Cyberdoc Medical Ltd | Health & social care | 2011 |
| Cybvantic Limited | Information & communication | 2019 |
| Cydron Surveying Ltd | Professional & scientific | 2026 |
| Cypher Principles Limited | Real estate | 2017 |
| D & S Pharma Ltd | Health & social care | 2009 |
| D & Z Tasty Ltd | Hospitality | 2022 |
| D Cottrell Limited | Health & social care | 2017 |
| D Frazer Holdings Ltd | Health & social care | 2025 |
| D I Clark Limited | Health & social care | 2009 |
| D Ilsley Limited | Health & social care | 2015 |
| D J M Macdonald Limited | Health & social care | 2015 |
| D Johnson Plastic Surgeon Ltd | Health & social care | 2010 |
| D Magee Medical Ltd | Health & social care | 2023 |
| D T N I Limited | Professional & scientific | 2014 |
| D'Mello Food Tech Solutions Ltd | Hospitality | 2024 |
| D. & D. Harvey Limited | Extraterritorial | 1983 |
| D. a. Solent Lifting Services Limited | Manufacturing | 2023 |
| D. Sandher Ltd | Health & social care | 2010 |
| D.I.Y. Solutions Limited | Wholesale & retail | 2005 |
| D.J. Profile & Grinding Co. Limited | Professional & scientific | 1995 |
| Daat Properties Limited | Households | 2025 |
| Dadlink Technologies Limited | Information & communication | 2025 |
| Daelz Ltd | Health & social care | 2019 |
| Daintree Asset Management Limited | Extraterritorial | 2017 |
| Daintree Wealth Tomorrow Ltd | Education | 2017 |
| Dakex Ltd | Wholesale & retail | 2020 |
| Dalal Consultancy Limited | Health & social care | 2014 |
| Dalal Surgery Limited | Health & social care | 2014 |
| Dallard Ltd | Information & communication | 2026 |
| Dalton Consulting Limited | Professional & scientific | 2019 |
| Daly QMS Solutions Limited | Professional & scientific | 2026 |
| DAN Dakin Limited | Real estate | 2014 |
| DAN Jones Sports Business Advisory Limited | Professional & scientific | 2023 |
| DAN Patel Dentistry Ltd | Health & social care | 2022 |
| Dancy Medical Services Limited | Health & social care | 2017 |
| Dancy RM Ltd | Health & social care | 2025 |
| Dando Property Rentals LLP | | 2022 |
| Daniel Williamson Designs in Wood Ltd | Other services | 2023 |
| Danielle Ormandy Limited | Health & social care | 2022 |
| Dannii Marie Ltd | Financial services | 2019 |
| DAP Engineering Services Ltd | Administrative & support | 2020 |
| DARE2DREAM 15 Ltd | Financial services | 2015 |
| Daren P Forward Ltd | Health & social care | 2015 |
| Dark Carbon Limited | Construction | 2005 |
| Darleywood Holdings Ltd | Real estate | 2025 |
| Darnhall Estates Limited | Real estate | 2015 |
| Darren Alawi Ltd | Information & communication | 2014 |
| Darwen Day Care for Dogs Ltd | Other services | 2017 |
| Dasidloff Ltd | Health & social care | 2025 |
| Dasset 413 Limited | Financial services | 2022 |
| Data Centre Environments Limited | Information & communication | 2009 |
| Data Centre Solutions Europe Limited | Information & communication | 2009 |
| DATA4LEADERS Ltd | Financial services | 2021 |
| Dataedge AI Foundry Ltd | Information & communication | 2026 |
| Daveylands Management Limited | Households | 2016 |
| David Beech Financial Services Ltd | Financial services | 2024 |
| David Eddowes Limited | Wholesale & retail | 1999 |
| David Leinhardt Limited | Health & social care | 2011 |
| David Loton Kitchens and Joinery Ltd | Construction | 2025 |
| David Mark Brown Limited | Administrative & support | 2013 |
| Davies Court Romiley RTM Company Limited | Real estate | 2018 |
| Daxesoft Limited | Information & communication | 1994 |
| Dazelway Limited | Professional & scientific | 2023 |
| Dazz Ltd | Real estate | 2019 |
| DB Tutoring Ltd | Education | 2022 |
| Dbconsultproject Ltd | Construction | 2025 |
| DBL Capital Ltd | Professional & scientific | 2026 |
| DCB Property Consultancy Limited | Construction | 2010 |
| DCG Trading 10 Limited | Health & social care | 2024 |
| DCG Trading 5 Limited | Health & social care | 2022 |
| DCG Trading 6 Limited | Administrative & support | 2022 |
| DCG Trading 7 Limited | Extraterritorial | 2022 |
| DCG Trading 8 Limited | Extraterritorial | 2022 |
| DCG Trading 9 Limited | Health & social care | 2024 |
| DCH Plumbing & Heating Ltd | Construction | 2022 |