| DSX Fitness Limited | Arts & recreation | 2016 |
| DT Engineering Services Ltd. | Wholesale & retail | 2016 |
| DT Transport Limited | Transport & logistics | 2023 |
| DT04 GAS Ltd | Construction | 2018 |
| DTC Foods Limited | Wholesale & retail | 2022 |
| DTD Boutique Ltd | Wholesale & retail | 2024 |
| DTD Elite Couriers Ltd | Transport & logistics | 2018 |
| DTD2 Ltd | Construction | 2025 |
| DTK & Daughters Limited | Professional & scientific | 2022 |
| DTP Plastering Limited | Construction | 2022 |
| Dublish Capital Ltd | Financial services | 2026 |
| Dublish Investments Ltd | Financial services | 2026 |
| Dubock Space Consulting Limited | Professional & scientific | 2013 |
| Duck Hill Farm Ltd | Agriculture & fishing | 2025 |
| Ducklings Pre-School Limited | Education | 2010 |
| Dudu Rendering Ltd | Construction | 2023 |
| DUE South Systems Limited | Information & communication | 2018 |
| Duemate Ltd | Information & communication | 2026 |
| Duetto Limited | Professional & scientific | 1991 |
| Duffy Transport & Storage Ltd | Transport & logistics | 2023 |
| DUG POG Ltd | Manufacturing | 2026 |
| Dujure Aura Solutions Ltd | Professional & scientific | 2025 |
| DUK Premium Travel Ltd | Transport & logistics | 2025 |
| Duka Transport Ltd | Transport & logistics | 2025 |
| Duke Web Designs Limited | Wholesale & retail | 2021 |
| Dukes Building Services Ltd | Construction | 2010 |
| Dukes Marine Services Ltd | Manufacturing | 2026 |
| Dukes Recovery Ltd | Transport & logistics | 2023 |
| Duma Transport Ltd | Transport & logistics | 2018 |
| Dunbridge Land Limited | Construction | 2001 |
| Duncan Hood Properties Ltd | Real estate | 2018 |
| Duncan Spice Ltd | Hospitality | 2021 |
| Dundridge Inns Ltd | Hospitality | 2024 |
| Dune Architects Ltd | Professional & scientific | 2025 |
| Dungaroos Pre-School Limited | Education | 2021 |
| Dungaroos Winchester Ltd | Education | 2024 |
| Dungbeetle Consulting Limited | Professional & scientific | 2023 |
| Dunkley Associates (Southampton) Ltd | Professional & scientific | 2022 |
| Dunns Automotive Ltd | Wholesale & retail | 2019 |
| Dunsell's Stone Limited | Households | 2016 |
| Dunton Park Caravan Sites Limited | Hospitality | 1960 |
| DUO Systems Ltd | Construction | 2020 |
| Duomac Limited | Information & communication | 2009 |
| Duquesa Holdings Limited | Financial services | 2020 |
| Durabilis Electrical & Maintenance Ltd | Construction | 2019 |
| Durabilis Holdings Limited | Construction | 2020 |
| Durabilis Limited | Construction | 1996 |
| Durban Court (Management) Limited | Households | 1967 |
| Durefa 2 Private Limited | Wholesale & retail | 2025 |
| Durgapur Mariner Ltd | Administrative & support | 2025 |
| Durley Car Centre Ltd | Wholesale & retail | 2020 |
| Durley House Limited | Hospitality | 2025 |
| Durley House Nursery & Learning Ltd | Health & social care | 2025 |
| Durley Ladybirds Pre-School Limited | Health & social care | 2020 |
| Durley Mews Management Company Limited | Households | 2001 |
| Durley Mews Orchard Management Company Limited | Households | 2014 |
| Dushi Electrical Ltd | Construction | 2021 |
| Dushi Properties Ltd | Real estate | 2023 |
| Dusk Creations Limited | Professional & scientific | 2024 |
| Dusky Tool Ltd | Wholesale & retail | 2026 |
| Dust Design Ltd | Professional & scientific | 2010 |
| Dust Group Limited | Financial services | 2019 |
| Dust Project Management Ltd | Professional & scientific | 2018 |
| Dustproof Ltd | Information & communication | 2017 |
| DV Smith Limited | Construction | 2026 |
| DVE Interiors Ltd | Construction | 2025 |
| DVG Facilities Management Ltd. | Administrative & support | 2023 |
| DW Enterprises (Southern) Limited | Hospitality | 2018 |
| DW Finishes Ltd | Construction | 2023 |
| DW Photography Ltd | Professional & scientific | 2023 |
| DW Training and Development Ltd | Professional & scientific | 2026 |
| Dw&El Limited | Real estate | 2024 |
| DWA South Ltd | Hospitality | 2024 |
| DWC Architecture Limited | Professional & scientific | 2022 |
| DWD Storage Ltd | Transport & logistics | 2025 |
| Dwelling Architects Ltd | Professional & scientific | 2016 |
| DWG Plans Franchises Limited | Administrative & support | 2025 |
| DWG Plans Limited | Professional & scientific | 2018 |
| DWH Group Holdings Limited | Financial services | 2024 |
| DWS Auto Repairs Limited | Manufacturing | 2014 |
| Dyena Ltd | Professional & scientific | 2012 |
| Dyer Bros. (Marine) Limited | Manufacturing | 1977 |
| Dylson Construction Ltd | Construction | 2019 |
| Dymat Group Ltd | Information & communication | 2015 |
| Dynameni Limited | Education | 2024 |
| Dynamic Drains Limited | Water & waste | 2023 |
| Dynamic Electrical Solutions Ltd | Construction | 2009 |
| Dynamic GB Investments Limited | Financial services | 2025 |
| Dynamic Install Projects Ltd | Construction | 2024 |
| Dynamic Investments Limited | Real estate | 2006 |
| Dynamic Load Monitoring (UK) Limited | Manufacturing | 1994 |
| Dynamic Positions Ltd | Administrative & support | 2006 |
| Dynamic Scaffolding Solutions Ltd | Construction | 2018 |
| Dynamika UK Ltd | Professional & scientific | 2006 |
| Dynamo School of Gymnastics UK Ltd | Arts & recreation | 2006 |
| Dynamon Ltd | Information & communication | 2015 |
| Dynamot Ltd | Transport & logistics | 2019 |
| Dynasty Roofing Ltd | Construction | 2025 |
| Dynx Marine Ltd | Other services | 2024 |
| Dyson Holdings Limited | Real estate | 1947 |