| Digital Photo Work Ltd | Information & communication | 2006 |
| Digital Space X Ltd | Professional & scientific | 2023 |
| Digitalent Limited | Professional & scientific | 2021 |
| Digitalwoohoo Limited | Information & communication | 2017 |
| Digitecture Limited | Information & communication | 2016 |
| Digitize Media Ltd | Other services | 2016 |
| Dignity and Marketing Global Ltd | Wholesale & retail | 2026 |
| Dignity Care Associates Ltd | Health & social care | 2021 |
| DIL & Sons Properties Ltd | Real estate | 2024 |
| Diligentis Ltd | Professional & scientific | 2018 |
| Dilityhome Ltd | Wholesale & retail | 2023 |
| Dilmer Limited | Wholesale & retail | 2013 |
| DIM Websites Ltd | Information & communication | 2025 |
| Dimmocks Lodge Limited | Real estate | 2010 |
| Dine at Thetford Ltd | Hospitality | 2024 |
| Dinero Solutions Ltd | Professional & scientific | 2025 |
| Dinners for Sinners Limited | Hospitality | 2002 |
| Dino Cuts Ltd | Other services | 2026 |
| Dino Scaffolding Ltd | Construction | 2019 |
| Dinoro Ltd | Construction | 2025 |
| Direct Assist Legal Limited | Information & communication | 2025 |
| Direct Insight Consulting Ltd | Information & communication | 2023 |
| Direct Online Deals Ltd | Wholesale & retail | 2019 |
| Direct Property Options Ltd | Real estate | 2017 |
| Direct Save Holdings Ltd | Real estate | 2019 |
| Direct Save Property Ltd | Real estate | 2024 |
| Direct Serviced Apartments Ltd | Hospitality | 2024 |
| Disability Watford | Health & social care | 2010 |
| Disco Fancy Hair Cuts Limited | Other services | 2019 |
| Discover Investments Ltd | Real estate | 2020 |
| Disha Solutions Limited | Information & communication | 2010 |
| Disol Limited | Professional & scientific | 2010 |
| Distinction Coaching Ltd | Education | 2021 |
| Distinctive Destinations Limited | Arts & recreation | 2008 |
| District J Limited | Administrative & support | 2013 |
| District One Training Ltd | Education | 2015 |
| Ditrinity Technologies Limited | Information & communication | 2022 |
| Diva Evental Limited | Hospitality | 2021 |
| Diverse Caribe Solutions Limited | Information & communication | 2010 |
| Diversified Services Ltd | Administrative & support | 2022 |
| Divine Clinic Ltd | Other services | 2024 |
| Divine Design Consultants Ltd | Professional & scientific | 2016 |
| Divine Love Ltd | Health & social care | 2018 |
| Divine Retail Limited | Wholesale & retail | 2024 |
| Divine Services (UK) Limited | Administrative & support | 2008 |
| Divitara Homes Ltd | Real estate | 2025 |
| Divyog Investment Ltd | Real estate | 2021 |
| Diyan Enterprise Ltd | Wholesale & retail | 2018 |
| DJ Property Group Limited | Real estate | 2025 |
| DJ Soul Revival Ltd | Arts & recreation | 2015 |
| Djas Ltd | Hospitality | 2026 |
| Djas Support Services Ltd | Construction | 2022 |
| DJC Lighting Ltd | Professional & scientific | 2016 |
| DJH Films Limited | Information & communication | 2022 |
| DJK Capital Limited | Professional & scientific | 2018 |
| DJM Building Contractors Limited | Construction | 2026 |
| Djml Heating Limited | Construction | 2016 |
| DJP Logistics Ltd | Transport & logistics | 2019 |
| DJW Consulting Services Ltd | Health & social care | 2023 |
| DJY International Ltd | Professional & scientific | 2015 |
| DKO Medical Ltd | Health & social care | 2024 |
| DL Corporate Limited | Hospitality | 2023 |
| DL Online Ltd | Wholesale & retail | 2019 |
| DLC Property Maintenance Limited | Construction | 2020 |
| Dld-Computer-Solutions.Com Ltd | Information & communication | 2015 |
| DLM Creative Ltd | Professional & scientific | 2013 |
| DLN Construction Ltd | Construction | 2019 |
| DLR Brothers Construction Ltd | Construction | 2025 |
| DM Building Services Watford Ltd | Construction | 2019 |
| DM Clinical and Professional Services Ltd | Education | 2019 |
| DM Couture Ltd | Administrative & support | 2016 |
| DM Heating & Plumbing Limited | Construction | 2016 |
| DM Intellect Ltd | Administrative & support | 2016 |
| DM IT Consultancy Services Ltd | Information & communication | 2015 |
| DM Motion Ltd | Other services | 2012 |
| DM Property Lettings Limited | Real estate | 2024 |
| DMA Logistics UK Limited | Transport & logistics | 2013 |
| Dmateriales Limited | Health & social care | 2026 |
| DMC Renewables UK Limited | Construction | 2024 |
| DMF Software Ltd | Information & communication | 2017 |
| DMG Financial Ltd | Professional & scientific | 2018 |
| DMK P S Ltd | Construction | 2026 |
| DML Consultants Limited | Professional & scientific | 2019 |
| Dmlk Video Limited | Information & communication | 2016 |
| DMP Flooring Ltd | Construction | 2023 |
| Dmpsales Limited | Wholesale & retail | 2024 |
| DMR Movies Ltd | Information & communication | 2022 |
| DMS Foods Limited | Hospitality | 2019 |
| DMT Fast Limited | Transport & logistics | 2020 |
| DMT Towbars Limited | Information & communication | 2014 |
| DN Advisors Ltd | Professional & scientific | 2024 |
| DN Blewitt Ltd | Construction | 2007 |
| DN Consulting Group Ltd | Information & communication | 2024 |
| DN Pharma Ltd | Financial services | 2023 |
| DNA Refurbishments Limited | Construction | 2017 |
| DNB Brickwork Limited | Construction | 2024 |
| Dnbconsult LP | | 2019 |
| DNC Construction Limited | Construction | 2018 |
| Dnets Limited | Information & communication | 2018 |
| Dnishk Ltd | Real estate | 2026 |