| Derw Coch Developments Limited | Construction | 2017 |
| Derw Joinery Company Ltd | Manufacturing | 2016 |
| Derwen Homes Limited | Real estate | 2002 |
| Design Construct Build Holdings Limited | Real estate | 2018 |
| Design Construct Build Solutions Limited | Construction | 2015 |
| Designscape Interiors Limited | Construction | 2023 |
| Destination Space Ltd | Professional & scientific | 2012 |
| Detailing Atelier Limited | Wholesale & retail | 2025 |
| Detailuxe Ltd | Wholesale & retail | 2025 |
| Deterrent Security Systems Ltd | Extraterritorial | 2014 |
| Detroit Grill Ltd | Hospitality | 2024 |
| Deva Technologies Limited | Professional & scientific | 2013 |
| Devastay Ltd | Real estate | 2023 |
| Development Bank of Wales Public Limited Company | Financial services | 2000 |
| Devine Joinery Limited | Construction | 2005 |
| Devine Property Services Limited | Construction | 2002 |
| Devonix Ltd | Professional & scientific | 2026 |
| Dewbs Ltd | Wholesale & retail | 2020 |
| Dexter Davies Group Ltd | Administrative & support | 2022 |
| DGB Electrical Services Ltd | Construction | 2017 |
| Dggd Ltd | Professional & scientific | 2022 |
| DGP Inspections Ltd | Professional & scientific | 2015 |
| DGT Plastering Services Ltd | Construction | 2015 |
| DH Pro-Com Solutions Ltd | Professional & scientific | 2025 |
| DHE (UK) Limited | Construction | 2013 |
| DHM Marketing Ltd | Other services | 2013 |
| Diamond Aerospace Limited | Manufacturing | 2017 |
| Diamond Companies Limited | Professional & scientific | 2013 |
| Diamond Metal Finishing Group Limited | Financial services | 2024 |
| Diamond Metal Finishing Holdings Limited | Financial services | 2016 |
| Dickin Property Limited | Real estate | 2025 |
| DIG IT Distribution Ltd | Wholesale & retail | 2025 |
| Digital Dreamz Limited | Other services | 2018 |
| Digital Marketing (China) Limited | Wholesale & retail | 2017 |
| Digital Pixies Ltd | Professional & scientific | 2018 |
| Digital Snap Ltd | Professional & scientific | 2025 |
| Digital Webworx Limited | Information & communication | 2022 |
| Dilly Blue Ltd | Manufacturing | 2019 |
| Dimmicks Accountancy and Business Advisers Ltd | Professional & scientific | 2003 |
| Direct IT Consulting Ltd | Information & communication | 2024 |
| Direct Kayaks Limited | Health & social care | 2014 |
| Direct Towing Limited | Wholesale & retail | 2021 |
| Dirty Protest Theatre Ltd | Arts & recreation | 2017 |
| Disc-Lock Europe Limited | Manufacturing | 1988 |
| Dispense Solutions (Wales) Limited | Extraterritorial | 2013 |
| Disputesolve Ltd | Professional & scientific | 2021 |
| Diverse Access Ltd | Construction | 2023 |
| Diverse Developments Ltd | Real estate | 2026 |
| Diverse Group Holdings Ltd | Financial services | 2026 |
| Divine by Design Limited | Extraterritorial | 2015 |
| DJ Davis Ltd | Health & social care | 2025 |
| DJ Plumbing & Heating NW Ltd | Construction | 2025 |
| DJ Wall Ventures Ltd | Financial services | 2026 |
| Dj&Son Transport Ltd | Transport & logistics | 2021 |
| DJC & SON Property Services Ltd | Construction | 2023 |
| DJC Validation Limited | Professional & scientific | 2016 |
| Djcontracts Limited | Construction | 2015 |
| DJH Invest Ltd | Real estate | 2026 |
| DJH R&D Limited | Professional & scientific | 2023 |
| DJTRANSPORT247 Ltd | Transport & logistics | 2018 |
| Dktrad Limited | Wholesale & retail | 2022 |
| DLE Care Consultancy Ltd | Other services | 2022 |
| Dlh.Joinery Limited | Construction | 2023 |
| DLI Engineering Solutions Limited | Professional & scientific | 2022 |
| DLK Restaurants Ltd | Hospitality | 2011 |
| Dllr NW Ltd | Financial services | 2025 |
| DLM Fitting and Engineering Ltd | Manufacturing | 2015 |
| DLM Mech Ltd | Wholesale & retail | 2025 |
| DLR Electrical Services Wrexham Ltd | Construction | 2022 |
| DLV Ventures Ltd | Financial services | 2025 |
| DM Building Solutions Ltd | Construction | 2014 |
| DM Business Services Limited | Professional & scientific | 2003 |
| DM17 Ltd | Transport & logistics | 2019 |
| DMC Sports Travel Ltd | Arts & recreation | 2013 |
| DMD Dental Ltd | Manufacturing | 2019 |
| DMG Services (Northern) Limited | Professional & scientific | 2024 |
| DMJ Roadside Retail Ltd | Wholesale & retail | 2019 |
| DMQ Limited | Education | 2003 |
| DMR Plumbing & Heating Limited | Construction | 2017 |
| DMR Property Maintenance Ltd | Real estate | 2018 |
| DMS Building Services (WXM) Limited | Construction | 2006 |
| Dmsm Ltd | Real estate | 2026 |
| DMV Consulting Limited | Professional & scientific | 2025 |
| DN & KD Holdings Limited | Manufacturing | 2023 |
| DND Homes Ltd | Real estate | 2019 |
| Dolwen Plumbing & Heating Ltd | Construction | 2025 |
| Domi Wood Ltd | Wholesale & retail | 2026 |
| Dominoe Investment Limited | Real estate | 2026 |
| Domus Planning Ltd | Information & communication | 2025 |
| Dondanny Ltd | Transport & logistics | 2019 |
| Done & Hampson Limited | Agriculture & fishing | 2025 |
| Done Together CIC | Education | 2025 |
| Donghai Wrexham Limited | Hospitality | 2025 |
| Doorex Ltd | Construction | 2025 |
| Douglas & Lord Properties Limited | Hospitality | 2015 |
| Douglas Cottage Holiday LET Limited | Hospitality | 2015 |
| Downtime Podcast Ltd | Information & communication | 2025 |
| DP Evans Electrical Ltd | Construction | 2014 |
| DR B B TAN Limited | Health & social care | 2016 |
| DR DP Property Ltd | Real estate | 2019 |