| D'Vinci Ltd | Professional & scientific | 2023 |
| D-Day Rifleman Tours Limited | Administrative & support | 2025 |
| D-Rehoboth Group Ltd | Real estate | 2025 |
| D-Sun Consultancy Ltd | Administrative & support | 2020 |
| D.Med Healthcare UK Ltd. | Wholesale & retail | 2016 |
| D.O. Flourish Mission Ltd | Wholesale & retail | 2023 |
| D.Q.M. Ltd. | Manufacturing | 1993 |
| D.R Kershaw Limited | Construction | 1960 |
| D.R. & J.F. Gamblin Limited | Agriculture & fishing | 1987 |
| D.S. Legal Services Limited | Professional & scientific | 2025 |
| D.S.R. Mechanical Services Limited | Construction | 2003 |
| D.V.P.5 Ltd | Construction | 2025 |
| D.W. Yachting Limited | Manufacturing | 2018 |
| D1THEAGENCY Ltd | Wholesale & retail | 2023 |
| D2 Limited | Professional & scientific | 1996 |
| D4 Health Ltd | Health & social care | 2022 |
| DA Corrosion Services Limited | Professional & scientific | 2009 |
| Daedalus Aviation & Heritage Group Ltd | Other services | 2007 |
| Daedalus Management Consultants Ltd | Professional & scientific | 2019 |
| Daily Driven Resto Limited | Wholesale & retail | 2026 |
| Daisy Chain Educational Services Limited | Education | 2014 |
| Daivani Consulting Services Limited | Information & communication | 2025 |
| Daker Ltd | Construction | 2013 |
| Dalgety Bay Specsavers Limited | Wholesale & retail | 2019 |
| Dalkeith Specsavers Limited | Wholesale & retail | 2007 |
| Dalkeith Visionplus Limited | Wholesale & retail | 2007 |
| Dalston Cross Specsavers Hearcare Limited | Wholesale & retail | 2013 |
| Dalston Cross Specsavers Limited | Wholesale & retail | 1996 |
| Daly Gardens Ltd | Administrative & support | 2022 |
| Daly Global Limited | Transport & logistics | 2019 |
| Daly Organs Ltd | Manufacturing | 2025 |
| Daly Systems Limited | Wholesale & retail | 1996 |
| Damteq Ltd. | Information & communication | 2017 |
| Damteq Solutions Ltd. | Information & communication | 2013 |
| DAN and Matt Property Services Limited | Real estate | 2025 |
| DAN Landscapes Ltd | Administrative & support | 2021 |
| Danamere Employee Benefits Limited | Financial services | 1999 |
| Danamere Investment Services Limited | Professional & scientific | 2018 |
| Dancing BEE Limited | Information & communication | 1995 |
| Danco Electrical Contractors Limited | Construction | 2016 |
| Dandelion Education and Culture Limited | Education | 2023 |
| Danger Danger Ltd | Professional & scientific | 2019 |
| Daniel's Special Care Ltd | Health & social care | 2016 |
| Danielle Williams Consultancy Ltd | Other services | 2019 |
| Danilux Studios Ltd | Professional & scientific | 2026 |
| Dansair Ltd | Professional & scientific | 2026 |
| DAP Property Services Ltd | Real estate | 2021 |
| Daring Futures Limited | Professional & scientific | 2017 |
| Darlington Specsavers Hearcare Limited | Wholesale & retail | 2013 |
| Darlington Specsavers Limited | Wholesale & retail | 1999 |
| Darlington Victoria Road Specsavers Limited | Wholesale & retail | 2022 |
| Darlington Visionplus Limited | Wholesale & retail | 1999 |
| Darnley Specsavers Limited | Wholesale & retail | 2023 |
| Darrell Nash Building Contractor Ltd | Construction | 2011 |
| Darren Edwards GAS Services Limited | Construction | 2016 |
| Dartmouth General Contractors Limited | Construction | 1976 |
| Daryl Boswell Ltd | Construction | 2022 |
| DAS PAD Limited | Real estate | 2024 |
| Dashwood Coffee Consultancy Limited | Information & communication | 2015 |
| Dasic US Holdings Number 1 Limited | Financial services | 2024 |
| Dasic US Holdings Number 2 Limited | Financial services | 2024 |
| Data Menu Limited | Information & communication | 2022 |
| Data Storage Solutions Ltd | Information & communication | 2021 |
| Dataquake Limited | Information & communication | 2019 |
| Datasym (U.K.) Limited | Administrative & support | 1988 |
| Dauntless Consulting Limited | Professional & scientific | 2025 |
| Dauntless Robotics Ltd | Professional & scientific | 2024 |
| Dave G. Family Butchers Limited | Wholesale & retail | 2002 |
| Dave SOS Ltd | Professional & scientific | 2015 |
| Daventry Specsavers Limited | Wholesale & retail | 2002 |
| David Day Limited | Information & communication | 2011 |
| David Huang Acupuncture Chinese Healthcare Limited | Health & social care | 2015 |
| David W. King (Builders) Limited | Construction | 1978 |
| David Wright Design Limited | Professional & scientific | 2008 |
| David Yusuf Ltd | Construction | 2004 |
| Davies Associates Limited | Information & communication | 2006 |
| Davincihomes Limited | Hospitality | 2023 |
| Davis Property Services GU Limited | Construction | 2018 |
| Davismith Ltd | Information & communication | 2023 |
| Daxter Electricals Ltd | Construction | 2024 |
| Day & Dwell Ltd | Real estate | 2025 |
| Daylight Window and Industrial Cleaning Services Limited | Administrative & support | 2007 |
| Dbax Media Ltd | Professional & scientific | 2023 |
| DBB Properties Limited | Real estate | 2016 |
| DBL Estates Limited | Administrative & support | 2017 |
| DBS Fixings Ltd | Wholesale & retail | 2023 |
| DBS Maintenance Limited | Construction | 2003 |
| DC Automotive and Tuning Ltd | Wholesale & retail | 2018 |
| DC Construction & Utilities Ltd | Construction | 2024 |
| DC Digitas Ltd | Professional & scientific | 2022 |
| DC Electrical Solutions Ltd | Construction | 2018 |
| DC Event Medical Ltd. | Health & social care | 2018 |
| DCG GAS Solutions Ltd | Construction | 2010 |
| DCL Old Co 2024 LCD Limited | Transport & logistics | 2022 |
| DCM Carpentry Ltd | Construction | 2017 |
| DCS Cleaning UK Ltd. | Other services | 2013 |
| DDM Fabrications Limited | Construction | 2018 |
| DE Construction UK Limited | Construction | 2007 |
| Deafheart CIC | Education | 2026 |
| Deakin Family Investment Company Limited | Real estate | 2023 |