| Doodle Chat CIC | Arts & recreation | 2025 |
| Doodoo Ltd | Professional & scientific | 2020 |
| Doodshisha Limited | Hospitality | 2024 |
| Doohickey Films Limited | Information & communication | 2015 |
| Dooncastle Consulting UK Limited | Information & communication | 2025 |
| Doonmag Property Ltd | Real estate | 2024 |
| Door Repairs (UK) Ltd | Construction | 2011 |
| Door SEC Training Services (DTS) Limited | Administrative & support | 2022 |
| Door Step Booze Limited | Hospitality | 2021 |
| Door Systems Design Ltd | Manufacturing | 1996 |
| Doors Nationwide Ltd | Wholesale & retail | 2025 |
| Doorstep Treats Ltd | Hospitality | 2025 |
| Doortech Limited | Extraterritorial | 2011 |
| Doorway Holdings Limited | Administrative & support | 2014 |
| Doorway Technology Services Limited | Professional & scientific | 2018 |
| Doorzadirect Ltd | Administrative & support | 2026 |
| Dope Sauce Ltd | Manufacturing | 2025 |
| Dope-Drape Ltd | Wholesale & retail | 2023 |
| Doran Digital Ltd | Professional & scientific | 2023 |
| Dorby Inns Limited | Real estate | 2002 |
| Dorea Genuine Care Ltd | Other services | 2021 |
| Doric Game Limited | Wholesale & retail | 1994 |
| Doris's Healthcare Ltd | Health & social care | 2020 |
| Dorlice PVT LMT Limited | Health & social care | 2015 |
| Dormy Hub Investments LLP | | 2007 |
| Dormy Memberco Limited | Administrative & support | 2015 |
| Dorota Gorska Ltd | Administrative & support | 2025 |
| Dorset Lighting (Finance) Limited | Administrative & support | 2006 |
| Dortech Architectural Systems Limited | Construction | 1990 |
| Dortech Direct Limited | Wholesale & retail | 2008 |
| Dortech Doors Limited | Professional & scientific | 2019 |
| Dortech Limited | Professional & scientific | 2007 |
| Dortech Maintenance Limited | Construction | 2011 |
| DOS Logistics Ltd | Transport & logistics | 2018 |
| Dosh Shop Ltd | Wholesale & retail | 2019 |
| Doshecomercial Ltd | Wholesale & retail | 2025 |
| Dosing Solutions (UK) Limited | Manufacturing | 2006 |
| Doski Stays Ltd | Real estate | 2026 |
| Doski Trading Ltd | Wholesale & retail | 2024 |
| DOT AD Limited | Information & communication | 2025 |
| DOT Cloud Tech Ltd | Information & communication | 2025 |
| DOT IT Media Ltd | Information & communication | 2025 |
| DOT Logistics Ltd | Transport & logistics | 2026 |
| DOT the Lions Ltd | Hospitality | 2015 |
| DOT to DOT Transport Hire Ltd | Transport & logistics | 2015 |
| Dota (UK) Ltd | Health & social care | 2011 |
| Dotnet Contracting Limited | Professional & scientific | 2022 |
| Dotnet Solutions UK Limited | Information & communication | 2018 |
| Dotoks Link Ltd | Administrative & support | 2026 |
| Dotvector Limited | Professional & scientific | 2021 |
| Double a Business Services Limited | Information & communication | 2008 |
| Double Glazing Machinery Limited | Administrative & support | 2008 |
| Double L Roofing Ltd | Administrative & support | 2019 |
| Double SIX Bricks Ltd | Real estate | 2022 |
| Double SIX Drinks Ltd | Manufacturing | 2019 |
| Double Spiral Consulting Ltd | Professional & scientific | 2019 |
| Double Trouble Darts Supplies Ltd | Wholesale & retail | 2025 |
| Double U Plant UK Ltd | Administrative & support | 2012 |
| Double V Lettings Limited | Real estate | 2021 |
| Doubleday Consulting Ltd | Information & communication | 2018 |
| Dougbell Limited | Professional & scientific | 2019 |
| Dough BRO Pizza MH Limited | Hospitality | 2021 |
| Dough Club Leeds Ltd | Hospitality | 2026 |
| Dough Realisations Limited | Manufacturing | 1972 |
| Doughlicious Pizzeria Ltd | Hospitality | 2025 |
| Doughty Hill Energy Limited | Real estate | 2024 |
| Dougie's Pets Limited | Extraterritorial | 2018 |
| Douglas Kitchen Ltd | Hospitality | 2024 |
| Douglas Roberts Ltd | Financial services | 2023 |
| Douglas Stuart Holdings Ltd | Financial services | 2021 |
| Douzer Properties Ltd | Real estate | 2025 |
| Dova Resource Ltd | Transport & logistics | 2026 |
| Dovandale Optics Ltd | Health & social care | 2019 |
| Dove Haigh Phillips LLP | | 2007 |
| Dove Help Ltd | Administrative & support | 2023 |
| Dovengill Business Services Limited | Professional & scientific | 2012 |
| Dover Castle Apartments Ltd | Real estate | 2025 |
| Dovetailors Limited | Manufacturing | 2011 |
| Dovgan Fit-Out Ltd | Construction | 2019 |
| Dovitee Limited | Wholesale & retail | 2019 |
| Dowde Ltd | Financial services | 2024 |
| Dowding & Mills (Nominees) Limited | Extraterritorial | 1946 |
| Dowding & Mills (Overseas) Limited | Financial services | 1978 |
| Dowding & Mills Luxembourg Limited | Extraterritorial | 2003 |
| Dowding & Mills(Uk) Limited | Extraterritorial | 1967 |
| Dowding and Mills Limited | Financial services | 1919 |
| Dowes Wealth Management Limited | Financial services | 2017 |
| Down From TEN Limited | Health & social care | 2019 |
| Down the Cove Group Ltd | Manufacturing | 2025 |
| Downcliffe House Hotel Limited | Construction | 2007 |
| Downsco Limited | Professional & scientific | 2021 |
| Downshaw Lodge Limited | Real estate | 2015 |
| Downshaw Property Limited | Health & social care | 2021 |
| Downtown Disco Promotions Limited | Arts & recreation | 2021 |
| Downtown Electrical Contractors Limited | Construction | 2005 |
| Downtown Traders Ltd | Wholesale & retail | 2024 |
| Dows Consulting Limited | Information & communication | 2017 |
| Dowsing and Reynolds Home Ltd | Manufacturing | 2024 |
| Dowson and Mason Incinerators Limited | Professional & scientific | 1987 |
| Dowson Brothers LLP | | 2010 |