| Digitall Consulting Limited | Information & communication | 2012 |
| Dijksman Planning (UK) LLP | | 2008 |
| Dijksman Planning Limited | Construction | 2010 |
| Diligent Business Holdings Limited | Financial services | 2022 |
| Diligent Commercial Services Limited | Administrative & support | 2018 |
| Diligent Homes and Construction Ltd | Administrative & support | 2026 |
| Dimpleda Limited | Wholesale & retail | 2022 |
| Dingley Family and Specialist Early Years Centres | Education | 2010 |
| Dipex | Health & social care | 2001 |
| Dipex Health Limited | Professional & scientific | 2004 |
| Discernai Ltd. | Information & communication | 2025 |
| Disciple Global Holdings Limited | Professional & scientific | 2024 |
| Discrimination Law Association (D.L.A.) | Other services | 1999 |
| Dishes Ltd | Hospitality | 2020 |
| Distributed Radio Limited | Information & communication | 2016 |
| Diverse Beauty Limited | Wholesale & retail | 2013 |
| Divine Pictures Ltd | Information & communication | 2020 |
| Divino Comercio Ltd | Administrative & support | 2024 |
| Division Zero Ltd | Information & communication | 2023 |
| DJB Business Finance Partnering Ltd | Professional & scientific | 2025 |
| Djpj Teeth Ltd | Health & social care | 2025 |
| DL Uprichard and SON Limited | Construction | 2011 |
| DLG Events Ltd | Administrative & support | 2016 |
| DLM Berkshire Limited | Other services | 2014 |
| DM Moto Mechanics Ltd | Wholesale & retail | 2021 |
| Dmctz Limited | Professional & scientific | 2012 |
| Dmgsclothing Ltd | Wholesale & retail | 2024 |
| DNL UK Ltd | Professional & scientific | 2006 |
| DNW Properties Ltd | Real estate | 2023 |
| Do-Good Consulting Ltd. | Other services | 2003 |
| Doberman Power Limited | Wholesale & retail | 2025 |
| DOC 4 Cars Ltd | Wholesale & retail | 2024 |
| Doctor Momo Ltd | Hospitality | 2025 |
| Document House HGS Limited | Professional & scientific | 2018 |
| Document House Trading Limited | Hospitality | 2018 |
| Doir Limited | Professional & scientific | 2014 |
| Dollhouse Pictures Ltd | Information & communication | 2010 |
| Dolmans (Newbury) Management Company Limited | Households | 2019 |
| Dolmans Flats Management Company Limited | Households | 2019 |
| Dolphin Motor Club (Newbury) Limited | Arts & recreation | 1985 |
| Domino Pictures Ltd | Information & communication | 2021 |
| Domsons Transport Ltd | Transport & logistics | 2018 |
| Donald Paine Consultancy Limited | | 1989 |
| Donberg Strategies Limited | Professional & scientific | 2005 |
| Done Homes Ltd | Construction | 2023 |
| Donnington (CF) Ltd | Construction | 2021 |
| Donnington (Kiln Farm) Ltd | Construction | 2018 |
| Donnington Construction Limited | Construction | 2019 |
| Donnington Elms Ltd | Households | 2004 |
| Donnington Highclere Ltd | Construction | 2020 |
| Donnington New Homes 2 Limited | Construction | 2021 |
| Donnington New Homes 3 Limited | Construction | 2022 |
| Donnington New Homes 4 Limited | Construction | 2024 |
| Donnington New Homes 5 Limited | Construction | 2024 |
| Donnington New Homes 6 Limited | Construction | 2025 |
| Donnington New Homes 7 Limited | Construction | 2025 |
| Donnington New Homes Ltd | Construction | 2020 |
| Donnington Valley Group Limited | Hospitality | 1990 |
| Donny’S Ltd | Wholesale & retail | 2025 |
| Doobeedoo Ltd | Professional & scientific | 2015 |
| Dormer Property Limited | Real estate | 2021 |
| DOW Legal Partners Limited | Information & communication | 2026 |
| Downland Services Limited | Wholesale & retail | 1995 |
| Downsview Road Wantage Limited | Extraterritorial | 2016 |
| Downview Residential Home Limited | Health & social care | 2022 |
| DR D’Sa Consulting Limited | Professional & scientific | 2023 |
| DR J Loader Ltd | Professional & scientific | 2024 |
| DR Thomas Millard Ltd | Health & social care | 2018 |
| Dragon Asphalt Ltd | Manufacturing | 2018 |
| Dragonfly 360 Ltd | Professional & scientific | 2012 |
| DRB B2B Ltd | Administrative & support | 2023 |
| DRC Corporate Trustee Limited | Financial services | 2020 |
| DRC Group Holdings Limited | Financial services | 2020 |
| Dream JAA Ltd | Real estate | 2024 |
| Drewitt Building and Civil Engineering Contractors Ltd | Construction | 2020 |
| Drewitt Plant Hire Ltd | Administrative & support | 2020 |
| Drhtg Ltd | Information & communication | 2024 |
| Drip Drip Plumbing Ltd | Construction | 2022 |
| Driveform New Roads & Streetworks Limited | Construction | 2005 |
| Drogo Estates Limited | Administrative & support | 2003 |
| Droneeye Ltd | Information & communication | 2020 |
| Drum With Alex Ltd | Education | 2023 |
| DSC Automotive Limited | Wholesale & retail | 2010 |
| DSG Consultancy Services Limited | Information & communication | 2007 |
| DSS Info Limited | Information & communication | 2019 |
| DT Houghton IT Solutions Ltd | Information & communication | 2013 |
| Dunasfern Auriga Limited | Extraterritorial | 2016 |
| Dunasfern Limited | Extraterritorial | 1983 |
| Dunmoore (West London) Limited | Real estate | 2016 |
| Dunmoore Group Limited | Real estate | 2006 |
| Dunmoore Limited | Real estate | 2006 |
| Dunmoore Properties Limited | Real estate | 2006 |
| Dunmoore Ventures Limited | Professional & scientific | 2003 |
| Dunston Park NO. 2 Limited | Real estate | 1996 |
| Dure Technologies Ltd | Information & communication | 2018 |
| Dust Mite Limited | Wholesale & retail | 2023 |
| Dwjl Holdings Ltd | Manufacturing | 2025 |
| DYK Consulting Limited | Other services | 2010 |
| Dynamic Pictures Ltd | Information & communication | 2020 |
| Dynamic Technical Services Limited | Construction | 2014 |