| DR Kerr Vascular Neurology Ltd | Health & social care | 2021 |
| DR. Thomas Gumbrielle | Health & social care | 2010 |
| Dredolt Limited | Real estate | 2026 |
| Drelect Ltd | Manufacturing | 2020 |
| Drift Property Ltd | Real estate | 2023 |
| Dristernan Holdings Limited | Financial services | 2026 |
| Drumallen Farm Ltd | Agriculture & fishing | 2023 |
| Drumbearn Limited | Financial services | 2005 |
| Drumcullen Farms Ltd | Agriculture & fishing | 2022 |
| Drumey Farm Limited | Agriculture & fishing | 2022 |
| Drumgold (NO.1) Limited | Agriculture & fishing | 2019 |
| Drumhirk Farm Ltd | Agriculture & fishing | 2015 |
| Drummond CPM Ltd | Professional & scientific | 2024 |
| Drumna Management Co Limited | Real estate | 2020 |
| Drumna Open Space Management Company Ltd | Real estate | 2020 |
| Drumquay Properties Limited | Extraterritorial | 2005 |
| Drygen Technologies Limited | Manufacturing | 2025 |
| DSE Trading Ltd | Transport & logistics | 2017 |
| DSK NI Properties Ltd | Real estate | 2023 |
| DSK Painting Ltd | Construction | 2016 |
| Dsta Ltd | Financial services | 2024 |
| DTS Civils and Drainage Supplies Ltd | Construction | 2022 |
| Duel Piercing Ltd | Other services | 2020 |
| Dun-Eden (IRL) Limited | Transport & logistics | 2019 |
| Dundeis Ltd | Financial services | 2021 |
| Dungannon (Oaks Park) Stadium Greyhound Racing Limited | Arts & recreation | 1995 |
| Dungannon Auto Body Centre Limited | Wholesale & retail | 2015 |
| Dungannon Bearing Co Ltd | Wholesale & retail | 2019 |
| Dungannon Cookstown Camera Club Limited | Arts & recreation | 2025 |
| Dungannon Enterprise Centre | Real estate | 1985 |
| Dungannon Golf Shop Limited | Wholesale & retail | 1996 |
| Dungannon Plant Sales (NI) Limited | Wholesale & retail | 2024 |
| Dungannon Spice Ltd | Hospitality | 2024 |
| Dungannon United Youth C.I.C. | Arts & recreation | 2010 |
| Dungannon Veterinary Centre Ltd | Professional & scientific | 2020 |
| Dungannon West Renewal Limited | Real estate | 1995 |
| Dungannon Window Company Limited | Manufacturing | 2003 |
| Dungannon Youth for Christ | Other services | 2010 |
| Dunloe Development Ltd | Construction | 2016 |
| Dunrich Green Ltd | Extraterritorial | 2022 |
| Dunrus Limited | Construction | 2007 |
| Dunvale Limited | Extraterritorial | 2011 |
| DWC Holdings (N.I.) Ltd | Financial services | 2021 |
| Dyal Solutions Ltd | Information & communication | 2026 |
| Dynamic Group Solutions Limited | Professional & scientific | 2020 |
| Dynamic Safety Solutions Ltd | Professional & scientific | 2014 |
| Dynamic Tank Solutions Ltd | Water & waste | 2019 |
| Dynes Trading Limited | Real estate | 2016 |
| E a Grimley & Co Limited | Professional & scientific | 2022 |
| E Conroy Services Limited | Wholesale & retail | 2025 |
| E Conroy Transport Limited | Transport & logistics | 2017 |
| E Daly Properties Ltd | Construction | 2020 |
| E Quinn Civils Ltd | Construction | 2003 |
| E Quinn Properties Limited | Real estate | 2023 |
| E Watt & Sons Ltd | Construction | 2022 |
| E. Quinn Contracts Limited | Construction | 2005 |
| EA Wind Ltd | Energy | 2022 |
| EAC Fitness Limited | Arts & recreation | 2025 |
| Eaeo Collective Ltd | Real estate | 2025 |
| Eagle Farms Ltd | Agriculture & fishing | 2025 |
| EAJ Contracts Ltd | Construction | 2016 |
| Earth Developments Limited | Construction | 2004 |
| East Antrim Newspapers Limited | Manufacturing | 2003 |
| Easy Energy Ltd | Wholesale & retail | 2002 |
| Easy Spray Foam Ltd | Construction | 2021 |
| Easydone Tree Surgeons Ltd | Administrative & support | 2025 |
| Ebbay Ltd | Health & social care | 2015 |
| EBK Holdings Ltd | Financial services | 2023 |
| EC Enterprises Ltd | Professional & scientific | 2018 |
| Eco Bedding Solutions Ltd | Administrative & support | 2020 |
| Eco Biomass (N.I.) Ltd | Water & waste | 2015 |
| Eco Management Solutions Limited | Extraterritorial | 2004 |
| Eco Solutions (N.I.) Limited | Water & waste | 2002 |
| Eco Structure NI Ltd | Construction | 2024 |
| Ecofac Group Ltd | Construction | 2026 |
| ECP Engineering Ltd | Manufacturing | 2020 |
| Edbf Ltd | Administrative & support | 2016 |
| Eden M & J Ltd | Other services | 2015 |
| Eden Wood Management Company Ltd | Households | 2018 |
| Edendork Electrical Wholesale Ltd | Wholesale & retail | 2023 |
| Edgar Transport Ltd | Transport & logistics | 2013 |
| Edge Innovate (NI) Limited | Manufacturing | 2011 |
| Edgewater Property Ltd | Real estate | 2022 |
| Edgewaterfoods Holdings Ltd | Financial services | 2022 |
| Edgewaterfoods Ltd | Manufacturing | 2015 |
| Edham Limited | Professional & scientific | 1993 |
| Edham Properties Limited | Extraterritorial | 2020 |
| Edmk Limited | Real estate | 2016 |
| EEC Joinery and Building Ltd | Construction | 2022 |
| Eglish Plant and Tool Hire Limited | Extraterritorial | 2020 |
| Eglish Property Ltd | Real estate | 2017 |
| Eirfuels UK Limited | Manufacturing | 2023 |
| Eirtrans Autologistics NI Limited | Transport & logistics | 2023 |
| EJR Contracts Ltd | Construction | 2024 |
| EK Engineering Ltd | Manufacturing | 2006 |
| EK Hold Co Limited | Financial services | 2026 |
| EK Networks (UK) Ltd | Construction | 2020 |
| Electrical Control Gear Ltd | Wholesale & retail | 2013 |
| Electro Mech Agri Limited | Manufacturing | 2000 |
| Electro Mech Holdings Ltd | Financial services | 2023 |