| D.J. Cullen Limited | Construction | 2006 |
| D2 Networks Ltd | Information & communication | 2021 |
| D360 International Ltd | Information & communication | 2017 |
| Dabm LDN Ltd | Health & social care | 2021 |
| Dacamo Limited | Real estate | 2025 |
| DAF Trucks Limited | Wholesale & retail | 1993 |
| Daglish Plumbing Limited | Construction | 2018 |
| DAI David Ltd | Professional & scientific | 2009 |
| Dailsp Ltd | Information & communication | 2021 |
| Daily Information Limited | Information & communication | 2005 |
| Dailyexpress Retail Ltd | Wholesale & retail | 2025 |
| Daimon Stroud Limited | Construction | 2018 |
| Dakphloid Ltd | Health & social care | 2023 |
| Dale Harris Consulting Limited | Professional & scientific | 2006 |
| Dale Place Management Company Limited | Real estate | 1986 |
| Dalia's Trade Ltd | Wholesale & retail | 2024 |
| Dall Chini Limited | Hospitality | 2025 |
| Dalmatian Ltd | Real estate | 2026 |
| Damprot Renovations Limited | Construction | 1975 |
| Danehurst RTM Company Limited | Real estate | 2023 |
| Dani ALU UK Limited | Manufacturing | 2012 |
| Daniel Kitchen Limited | Financial services | 2003 |
| Daniel Quarter 63 Limited | Real estate | 2007 |
| Daniel Quarter 66 Limited | Real estate | 2007 |
| Daniel Quarter 67 Limited | Real estate | 2007 |
| Danny BOI Ltd | Hospitality | 2022 |
| Danny BOY Trading Company Limited | Wholesale & retail | 2007 |
| Dantone Electrical Limited | Wholesale & retail | 2007 |
| Dapc Consulting Ltd | Professional & scientific | 2025 |
| Dapper Dogs of Oxford Ltd | Other services | 2022 |
| Darakeh Ltd | Construction | 2026 |
| Dare to Taste Ltd | Hospitality | 2023 |
| Dargala Barber Ltd | Other services | 2020 |
| Darhomes Ltd | Real estate | 2025 |
| Darivy Transport Services Limited | Transport & logistics | 2023 |
| Dark Blue Therapeutics Ltd | Professional & scientific | 2020 |
| Dark Enterprise Ltd | Information & communication | 2012 |
| Darnell Construction Limited | Construction | 1997 |
| Darnell Project Services Ltd | Professional & scientific | 2016 |
| Darnells Holdings Limited | Financial services | 2017 |
| Darnells Trustee Limited | Professional & scientific | 2017 |
| Darowski Ltd | Hospitality | 2014 |
| Dars Consulting (UK) Limited | Administrative & support | 1999 |
| Dars Films Limited | Administrative & support | 2020 |
| Dars Trading Limited | Information & communication | 2025 |
| Darwin Connect Limited | Information & communication | 2015 |
| Darwin MGA Ltd | Financial services | 2026 |
| Darwin Real Estate Ltd | Real estate | 2025 |
| Darwinian Ltd | Professional & scientific | 2019 |
| DAS Auto Limited | Wholesale & retail | 2008 |
| DAS Computer Ltd | Information & communication | 2009 |
| Das-Lowndes Limited | Health & social care | 2015 |
| Dasein Group Holdings Ltd | Other services | 2017 |
| Dasein Leadership Development | Education | 2010 |
| Dasein Ltd | Other services | 2021 |
| Dasein Solutions & Associates | Other services | 2011 |
| Dashanli Ltd | Wholesale & retail | 2026 |
| Dashi Construction Oxford Limited | Construction | 2022 |
| Dashwood Network Services Limited | Information & communication | 2008 |
| Dass&Soms Air Freight Ltd | Transport & logistics | 2025 |
| Data Adventures Ltd | Information & communication | 2026 |
| Data Crowd Limited | Information & communication | 2023 |
| Data Kraken Consultancy Limited | Professional & scientific | 2014 |
| Data Plastics Limited | Manufacturing | 1990 |
| Data Scientist Hub Ltd | Information & communication | 2017 |
| Dataplicity Limited | Extraterritorial | 2013 |
| Datapress Ltd. | Information & communication | 2013 |
| Datarx UK Ltd | Information & communication | 2021 |
| Datasalon Ltd | Information & communication | 2006 |
| Datasalon Trustee Ltd | Professional & scientific | 2026 |
| Datavacy Ltd | Information & communication | 2026 |
| Datavor Limited | Information & communication | 2026 |
| Date and Drip Limited | Wholesale & retail | 2025 |
| Daudhar & Sons Limited | Real estate | 2021 |
| Daudhar News Ltd | Wholesale & retail | 2021 |
| Dave Wheater Consulting Limited | Professional & scientific | 2025 |
| Davenant Court Management Company Limited | Households | 1990 |
| Davenport Court Management Limited | Administrative & support | 2005 |
| Daves Convenience Store Ltd | Wholesale & retail | 2021 |
| Davey & Weber Independent Financial Advisers Ltd | Professional & scientific | 2017 |
| David a Hills Ltd | Professional & scientific | 2014 |
| David and Solomon Ltd | Wholesale & retail | 2025 |
| David Dodwell Limited | Administrative & support | 2010 |
| David Fickling Books Limited | Information & communication | 2012 |
| David Fickling Comics Limited | Wholesale & retail | 2011 |
| David Fickling Publishing Limited | Administrative & support | 2000 |
| David J Roberts Ltd | Information & communication | 2013 |
| David Keene Limited | Administrative & support | 2008 |
| David Nery Ltd | Health & social care | 2010 |
| David Norbury Limited | Professional & scientific | 2006 |
| David Shorten Building Limited | Construction | 2005 |
| David Thatcher Carpentry and Joinery Limited | Construction | 2017 |
| David Tolley Limited | Arts & recreation | 1994 |
| David Ward Services Limited | Health & social care | 2015 |
| Davidanjoye Enterprises Ltd | Manufacturing | 2021 |
| Davidayanltd Ltd | Construction | 2019 |
| Dawn Conn Sculpture Limited | Arts & recreation | 2023 |
| Dawntreader Media Ltd | Professional & scientific | 2024 |
| Dawood Amir Ltd | Transport & logistics | 2025 |
| Day and Nightcare Assistance Limited | Administrative & support | 2015 |