| DSZ Transport Ltd | Transport & logistics | 2019 |
| DT Autocentre Limited | Wholesale & retail | 2017 |
| DT Productions Ltd | Arts & recreation | 2016 |
| DT VIE Limited | Information & communication | 2023 |
| DTD Group Limited | Hospitality | 2021 |
| DTG Consultants Ltd | Professional & scientific | 2018 |
| DTGK2023 Limited | Health & social care | 2023 |
| Dthes-Tekh CIC | Information & communication | 2023 |
| DTJ Property Maintenance Limited | Extraterritorial | 2026 |
| Dtjdistributions Ltd | Wholesale & retail | 2026 |
| DTM Diesel & Petrol Injection Specialists Limited | Wholesale & retail | 2002 |
| DTP Associates Limited | Administrative & support | 1996 |
| DTS Workshop Ltd | Information & communication | 2014 |
| Dts&S Ltd | Information & communication | 2017 |
| DUA Baker's Ltd | Manufacturing | 2024 |
| Dualeh Dynasty Ltd | Wholesale & retail | 2025 |
| Duality Quantum Photonics Ltd | Professional & scientific | 2020 |
| Duarti Ltd | Extraterritorial | 2022 |
| Duaxis Global Ltd | Administrative & support | 2025 |
| DUB Station Ltd | Manufacturing | 2018 |
| Dubplate Delivery Ltd | Information & communication | 2021 |
| Dubplate Style Limited | Information & communication | 2020 |
| Ducatechs Ltd | Professional & scientific | 2020 |
| Ducentis Biotherapeutics Ltd. | Professional & scientific | 2014 |
| Duchess HR Ltd | Administrative & support | 2021 |
| Ducie Road Management Company Limited | Households | 2015 |
| Duck & Goose Design Ltd | Information & communication | 2020 |
| Duck Trio Limited | Information & communication | 2024 |
| Duckett Allerton Limited | Real estate | 2025 |
| Duckmoor Ltd | Financial services | 2021 |
| Duda Property Ltd. | Real estate | 2024 |
| Dudbridge Engineering Limited | Manufacturing | 2001 |
| Dudbridge Property Management Ltd | Real estate | 2022 |
| Dudecake Bristol Ltd | Manufacturing | 2026 |
| Dudek - Trans Ltd | Transport & logistics | 2012 |
| Dudes & Dogs C.I.C. | Health & social care | 2019 |
| Dudes N Dolls Beauty Limited | Other services | 2015 |
| Duel Impact Ltd | Real estate | 1999 |
| Duet AI Ltd | Information & communication | 2026 |
| Duhok Food Ltd | Hospitality | 2025 |
| Duhok Grill Ltd | Hospitality | 2025 |
| Duit Together Ltd | Information & communication | 2025 |
| Duke Grooves Ltd | Education | 2021 |
| Duke's Head Highgate Limited | Hospitality | 2013 |
| Dukes Independent Financial Advisers Ltd | Professional & scientific | 2012 |
| Dukesbridge Limited | Households | 1987 |
| Dulai Sons Properties Ltd | Real estate | 2022 |
| Dulcie Real Estate Ltd | Real estate | 2021 |
| Duli's Cafe Limited | Hospitality | 2022 |
| Dumar Park Investments Limited | Real estate | 2002 |
| Dume Consulting Ltd | Information & communication | 2018 |
| Dumi Walls Ltd | Construction | 2019 |
| Dumnonia Financial Services Limited | Financial services | 1998 |
| Dump the Scales CIC | Health & social care | 2025 |
| Dumtoni Links Limited | Transport & logistics | 2026 |
| DUN Law 1 Repowering Limited | Energy | 2026 |
| Dunamis Property Limited | Real estate | 2020 |
| Dunbar Workshops Limited | Real estate | 1931 |
| Dunbridge Mill Limited | Hospitality | 2017 |
| Duncan & Sons Electrical Ltd | Extraterritorial | 2025 |
| Duncan Clifton Limited | Education | 2016 |
| Duncan House Management Company Limited | Households | 1994 |
| Duncan Stewart Ltd | Professional & scientific | 2012 |
| Duncan’S Tradesmen & Decorators Ltd | Extraterritorial | 2026 |
| Dunchi Cleaning Solutions Limited | Administrative & support | 2025 |
| Duncorr Limited | Professional & scientific | 2015 |
| Dundry Lane Vineyard Ltd | Agriculture & fishing | 2020 |
| Dune Island Limited | Professional & scientific | 2012 |
| Dunell Media Limited | Information & communication | 2018 |
| Dunesale Limited | Real estate | 1997 |
| Dunford Engineering Services Limited | Professional & scientific | 2009 |
| Dunk Limited | Professional & scientific | 2004 |
| Dunkeld News and Media Ltd | Information & communication | 2013 |
| Dunkerton Regeneration Limited | Real estate | 2022 |
| Dunkleys F H Limited | Real estate | 1999 |
| Dunleavy House Management Co. Limited | Real estate | 1980 |
| Dunleavy Vineyards Limited | Agriculture & fishing | 2008 |
| Dunluce Investments Limited | Financial services | 2019 |
| Dunmow Solar Limited | Energy | 2022 |
| Dunn & Mcdonagh Property Development Ltd | Construction | 2026 |
| Dunn's Ground Maintenance Ltd | Administrative & support | 2022 |
| Dunnill Dermatology Consulting Ltd | Health & social care | 2018 |
| Dunstan Mews Management Company Limited | Real estate | 2011 |
| Dunya Supermarket Ltd | Wholesale & retail | 2018 |
| DUO Hairdressing Limited | Other services | 2013 |
| DUO Properties South West Ltd | Real estate | 2024 |
| DUO Tech Holdings Limited | Administrative & support | 2009 |
| Duolec Ltd | Construction | 2015 |
| Duomax Hygiene Limited | Other services | 2013 |
| Duplex Property L a Limited | Real estate | 2006 |
| Duplify Ltd | Extraterritorial | 2024 |
| Duport Accountants Ltd | Professional & scientific | 2010 |
| Duport Associates Limited | Administrative & support | 1997 |
| Duport Director Limited | Professional & scientific | 1998 |
| Duport Domains Ltd | Extraterritorial | 2010 |
| Duport Ltd | Extraterritorial | 2005 |
| Duport Online Limited | Extraterritorial | 2005 |
| Duport Secretary Limited | Professional & scientific | 1998 |
| Dura Holdings Limited | Professional & scientific | 1951 |
| Dura UK Limited | Extraterritorial | 1998 |