| Dcba Ltd | Real estate | 2017 |
| Dcch Experts LLP | | 2019 |
| DD Car Sales Ltd | Wholesale & retail | 2026 |
| DDL Ductwork Ltd | Construction | 2016 |
| DDL Investments Ltd | Real estate | 2024 |
| DDN Group Ltd | Professional & scientific | 2023 |
| Ddws Limited | Extraterritorial | 2001 |
| DE Bream Ltd | Real estate | 2000 |
| DE Cornerstone Limited | Administrative & support | 2018 |
| DE Ferranti Limited | Construction | 2004 |
| DE Havilland Aircraft Museum Trust Limited | Arts & recreation | 1982 |
| DE Havilland Philharmonic Productions Ltd | Arts & recreation | 2017 |
| Deadline Flooring Commercial Limited | Construction | 2014 |
| Deal Sauce Ltd | Households | 2025 |
| Deamer Developments Limited | Real estate | 2007 |
| Deamer Limited | Construction | 2013 |
| Dean Clack Haulage Limited | Transport & logistics | 2008 |
| Dean Turner Limited | Professional & scientific | 2015 |
| DEB Report Writing Limited | Health & social care | 2023 |
| Deben River Consulting Limited | Information & communication | 2022 |
| Deborah Marchant Costumes Limited | Manufacturing | 2003 |
| Decami Ltd | Professional & scientific | 2016 |
| Decentre Studio Limited | Information & communication | 2025 |
| Deciderlab Limited | Professional & scientific | 2018 |
| Decision Studio Limited | Information & communication | 2016 |
| Decom Marine Limited | Construction | 2010 |
| Decor and Pour Limited | Wholesale & retail | 2025 |
| Decorous Limited | Information & communication | 2011 |
| DEE a Investments Ltd | Real estate | 2025 |
| Deep Blue Thinking Ltd | Professional & scientific | 2018 |
| Deep Branch Biotechnology Ltd | Professional & scientific | 2018 |
| Deep in Nature Ltd | Education | 2019 |
| Deep Lake Ltd | Professional & scientific | 2022 |
| Define Real Estate Limited | Extraterritorial | 2015 |
| Defined Technical Ltd | Professional & scientific | 2016 |
| Defontes Limited | Professional & scientific | 2014 |
| Dejb Coaching Limited | Education | 2024 |
| Delava Care Limited | Health & social care | 2014 |
| Delian Alliance Industries UK Ltd | Public administration | 2024 |
| Delicias Ibericas Ltd | Wholesale & retail | 2023 |
| Delivering London Ltd | Transport & logistics | 2020 |
| Delivery Direct Limited | Hospitality | 2003 |
| Delivery Insider Limited | Professional & scientific | 2020 |
| Delta Accountancy Advice Ltd | Professional & scientific | 2015 |
| Delta Builders Ltd | Construction | 2025 |
| Delta T Engineering Ltd | Professional & scientific | 2019 |
| Delwita Fine Teas UK Ltd | Wholesale & retail | 2025 |
| Demoncode Ltd | Information & communication | 2009 |
| Demystified Limited | Professional & scientific | 2015 |
| Denby Brown Consulting Limited | Hospitality | 2015 |
| Denis Crowe Consulting Limited | Professional & scientific | 2012 |
| Dens Energy UK Ltd | Energy | 2026 |
| Dente DE Leão Ltd | Manufacturing | 2023 |
| Dentistry by DR Selma Ltd | Health & social care | 2022 |
| Department of Help Limited | Professional & scientific | 2020 |
| Dermakind Aesthetics Ltd | Other services | 2023 |
| Dernol Investments Limited | Real estate | 1955 |
| DES RES Hertfordshire Ltd | Real estate | 2016 |
| Design & Direction Ltd | Professional & scientific | 2017 |
| Design Link (UK) Limited | Administrative & support | 2000 |
| Designer Accessories for Less Ltd | Wholesale & retail | 2024 |
| Deskspace Corporation Limited | Information & communication | 2020 |
| Deskspace Limited | Professional & scientific | 1999 |
| Deskspace Systems Limited | Information & communication | 2010 |
| Desmond & Sons Limited | Other services | 2012 |
| Destiny Rising.Co.Uk Limited | Administrative & support | 2009 |
| Detail Internet Limited | Information & communication | 2020 |
| Deus Auri Ltd | Real estate | 2024 |
| DEUTERON818 Consulting Limited | Information & communication | 2018 |
| Devarj Investment Limited | Information & communication | 2026 |
| Devenia Limited | Professional & scientific | 2007 |
| Devever Ltd | Information & communication | 2024 |
| Devon Court Residents (ST. Albans) Limited | Households | 1971 |
| Devon Door Distribution Limited | Manufacturing | 2023 |
| Dewars Fork Trucks Limited | Administrative & support | 2004 |
| DFA Design Group Limited | Professional & scientific | 2017 |
| DG Magenta Ltd | Health & social care | 2025 |
| Dgdw Ltd | Administrative & support | 2024 |
| Dgfo LLP | | 2011 |
| DGW Creative Ltd | Professional & scientific | 2024 |
| DH Chem Consultancy Ltd | Professional & scientific | 2023 |
| Dharma Sun Ltd | Education | 2025 |
| Dharuchini Spice Ltd | Hospitality | 2026 |
| DHB Surveying Ltd | Professional & scientific | 2023 |
| Dhruv Enterprises Limited | Extraterritorial | 2022 |
| Dhyan Ventures LP | | 2022 |
| Dial a Drink Limited | Wholesale & retail | 2002 |
| Dialcourt Properties Limited | Real estate | 1994 |
| Diamond Clinic Ltd | Health & social care | 2025 |
| Diamond Pathways C.I.C. | Education | 2026 |
| Diamond Realisations Limited | Wholesale & retail | 1961 |
| Diamonds CUT Garage Ltd | Manufacturing | 2018 |
| Diana Designs Limited | Wholesale & retail | 2023 |
| Diaphora Ltd | Administrative & support | 2022 |
| Dickens&Sons Ltd | Hospitality | 2016 |
| Diesel Parts Trading Ltd | Wholesale & retail | 2021 |
| Digby Installation Services Limited | Construction | 2000 |
| Diggy Diggy Limited | Real estate | 2021 |
| Digicon Media Limited | Financial services | 2024 |
| Digita Limited | Information & communication | 1989 |