| DW Build Ltd | Construction | 2021 |
| DW Electrical Services (NW) Ltd. | Administrative & support | 2017 |
| DWA Koty Crewe Ltd | Wholesale & retail | 2018 |
| Dwayne Spence Football School C.I.C. | Education | 2021 |
| DWB Cleaning Services Ltd | Households | 2013 |
| Dwell & Flow Consultancy Ltd | Professional & scientific | 2026 |
| Dwell Living Limited | Construction | 2014 |
| Dwelling Estates Ltd | Hospitality | 2011 |
| Dwellithproperties Ltd | Real estate | 2024 |
| Dwli Ltd | Wholesale & retail | 2018 |
| DWP Stores Ltd | Wholesale & retail | 2015 |
| DWR Advisory Ltd | Financial services | 2018 |
| DWR Cymru (Financing) UK PLC | Administrative & support | 2019 |
| DWR Cymru (Holdings) Limited | Professional & scientific | 2000 |
| DWR Cymru Cyfyngedig | Water & waste | 1989 |
| DWR Loans Ltd | Professional & scientific | 2025 |
| Dwyer Test Limited | Information & communication | 2018 |
| Dwyryd Ventures Ltd | Wholesale & retail | 2026 |
| DX CRF Ltd | Wholesale & retail | 2025 |
| DXB Developments Ltd | Construction | 2019 |
| Dyce Writing Services Ltd | Information & communication | 2025 |
| Dydja International Trading Company Limited | Wholesale & retail | 2025 |
| DYE Consulting Ltd | Information & communication | 2023 |
| Dyffryn CYF. | Information & communication | 2018 |
| Dyffryn Management Limited | Households | 2014 |
| Dyffryn Pharma Limited | Wholesale & retail | 2025 |
| Dyffryn Properties Limited | Real estate | 2025 |
| Dyffryn Springs Catering Limited | Hospitality | 2018 |
| Dyfiant Ltd | Information & communication | 2020 |
| DYL Enterprises Ltd | Real estate | 2023 |
| Dylanmolly (UK) Co., Ltd | Manufacturing | 2018 |
| Dyldn Ltd | Information & communication | 2018 |
| Dylilah Ltd | Professional & scientific | 2017 |
| Dylilah Pet Services Limited | Professional & scientific | 2024 |
| DYM 2019 Ltd | Construction | 2019 |
| Dynalix Limited | Information & communication | 2025 |
| Dynamic 365 Solutions Ltd | Information & communication | 2017 |
| Dynamic Business Consulting Ltd | Professional & scientific | 2010 |
| Dynamic Couriers Ltd | Transport & logistics | 2025 |
| Dynamic Development Group Limited | Construction | 2021 |
| Dynamic Digitizing Ltd | Wholesale & retail | 2024 |
| Dynamic Floorcare Ltd | Other services | 2022 |
| Dynamic Games Hub Ltd | Information & communication | 2025 |
| Dynamic Information Systems Limited | Information & communication | 2012 |
| Dynamic International Service Ltd | Wholesale & retail | 2024 |
| Dynamic Maintenance Group Limited | Energy | 2020 |
| Dynamic Rigging Limited | Administrative & support | 2016 |
| Dynamic SDS Ltd | Transport & logistics | 2025 |
| Dynamic Sense Consulting Ltd | Professional & scientific | 2012 |
| Dynamic Solutions 3D Ltd | Professional & scientific | 2025 |
| Dynamic Ventures Consultancy Ltd | Wholesale & retail | 2026 |
| Dynamic X Plus Ltd | Information & communication | 2022 |
| Dynamicable Ltd | Professional & scientific | 2018 |
| Dynamicas Solutions Ltd | Professional & scientific | 2018 |
| Dynamics Hands Services Ltd | Administrative & support | 2018 |
| Dynamics Special Limited | Administrative & support | 2024 |
| Dynamo Cover Limited | Financial services | 2013 |
| Dynamo Properties Ltd | Real estate | 2020 |
| Dynamo SVS Limited | Construction | 2014 |
| Dynasty Agency Ltd | Wholesale & retail | 2026 |
| Dynasty Build UK Limited | Construction | 2018 |
| Dyneros Ltd | Information & communication | 2025 |
| Dynes Engineering Limited | Professional & scientific | 1991 |
| Dynic (UK) Ltd | Manufacturing | 1989 |
| Dyns Ltd | Wholesale & retail | 2019 |
| Dyollith Limited | Hospitality | 2013 |
| Dyota Enterprise Ltd | Transport & logistics | 2026 |
| Dysgu Ltd | Professional & scientific | 2020 |
| Dyslexia Cardiff Ltd | Health & social care | 2015 |
| Dyslexia Show Ltd | Administrative & support | 2019 |
| Dyssis Mucuna Ltd | Information & communication | 2025 |
| DZ FOX Ltd | Wholesale & retail | 2025 |
| DZ Leisure Limited | Hospitality | 2019 |
| Dzine Digital Ltd | Information & communication | 2024 |
| E & a Heating and Plumbing Limited | Construction | 2015 |
| E & E Hotels Ltd | Hospitality | 2013 |
| E & G Jones Developments Ltd | Construction | 2023 |
| E & M Motor Company Limited | Wholesale & retail | 2019 |
| E & N Universe Foundation | Administrative & support | 2022 |
| E & P Global Survey & Recovery Services Company Limited | Professional & scientific | 2008 |
| E a T Consultancy Ltd | Professional & scientific | 2015 |
| E a Valeting Centre Ltd | Other services | 2015 |
| E Adams Enterprises Ltd | Transport & logistics | 2019 |
| E C R Concepts Software Ltd | Professional & scientific | 2004 |
| E Citybike.Com Ltd | Wholesale & retail | 2018 |
| E COM & International Trade Development Limited | Wholesale & retail | 2021 |
| E Commerce Global Limited | Wholesale & retail | 2019 |
| E Commerce House Ltd | Wholesale & retail | 2025 |
| E Commerce WORLD2 Limited | Wholesale & retail | 2025 |
| E Commodities UK Limited | Professional & scientific | 2017 |
| E Cross Borders Limited | Wholesale & retail | 2025 |
| E D M Electrical Limited | Construction | 2014 |
| E D R Management Ltd | Financial services | 2015 |
| E Frost Ltd | Other services | 2019 |
| E J Morgan Transport Ltd | Transport & logistics | 2007 |
| E K Electronics Design Ltd | Professional & scientific | 2016 |
| E K Textile Store Ltd | Wholesale & retail | 2021 |
| E Kandrotas Limited | Professional & scientific | 2016 |
| E L PR & Media Consultancy (UK) Ltd | Professional & scientific | 2018 |
| E Mwambene Limited | Transport & logistics | 2019 |