| Delicate Jade Limited | Wholesale & retail | 2023 |
| Demand QA Ltd | Information & communication | 2024 |
| Demesne Hollow Management Company Limited | Real estate | 2011 |
| Demo Tralor Limited | Wholesale & retail | 2025 |
| Dennett Engineering Ltd | Manufacturing | 2022 |
| Deoglas UK Ltd | Information & communication | 2025 |
| Derry Cathal Carroll Ltd | Wholesale & retail | 2025 |
| DFR Ventures Limited | Financial services | 2025 |
| Dhuri TIA Limited | Wholesale & retail | 2024 |
| Diamond Nails & Spa 71 Ltd | Other services | 2025 |
| Dickon Hall Fine Art Limited | Arts & recreation | 2019 |
| Digicoders Ltd | Information & communication | 2023 |
| Digicraft Solutions Limited | Information & communication | 2024 |
| Dihanary Limited | Other services | 2012 |
| Dimantas Limited | Wholesale & retail | 2025 |
| Dinghong Limited | Wholesale & retail | 2024 |
| Dingja Limited | Manufacturing | 2024 |
| Dining at Spice Island Limited | Hospitality | 2023 |
| Direct Cremations Ireland Limited | Other services | 2019 |
| Dirt Promotions Ltd | Arts & recreation | 2014 |
| Discoveries Limited | Wholesale & retail | 2025 |
| Distinct Designs Direct Ltd | Wholesale & retail | 2023 |
| DJD Lighting Ltd | Professional & scientific | 2021 |
| DJH Boiler Services Ltd | Construction | 2018 |
| DJH Hamilton Ltd | Wholesale & retail | 2014 |
| DJW Scrabo Ltd | Hospitality | 2023 |
| DMC Secure Ltd | Construction | 2014 |
| DNA Informatics Ltd | Information & communication | 2008 |
| Doan Properties Ltd | Real estate | 2017 |
| Dodo Delivery Limited | Transport & logistics | 2024 |
| Doe’S Leap Ltd | Real estate | 2025 |
| Dolmen Properties Limited | Real estate | 2004 |
| Domski Property Ltd | Real estate | 2024 |
| Donaghadee Developments Ltd | Construction | 2020 |
| Donard Cycling Limited | Manufacturing | 2016 |
| Dong West Ltd | Wholesale & retail | 2025 |
| Dorrian Quality Developments Ltd | Construction | 2006 |
| Double Taste Sweets Limited | Wholesale & retail | 2024 |
| Down Pallets Limited | Manufacturing | 2022 |
| Down Property Investment Ltd | Real estate | 2022 |
| Downey Accountancy Ltd | Professional & scientific | 2021 |
| Downeys (Holdings) Limited | Professional & scientific | 2016 |
| Downeys Cars (N.I.) Ltd | Wholesale & retail | 1990 |
| Downeys Rental Limited | Administrative & support | 2016 |
| DP Brickworks Ltd | Construction | 2025 |
| DP BUS Company Limited | Transport & logistics | 2019 |
| DR Automotive (Ards) Ltd | Wholesale & retail | 2023 |
| DR J N Chambers Limited | Health & social care | 2026 |
| Drains to Flow Ltd | Water & waste | 2022 |
| Dreiz Bespoke Limited | Wholesale & retail | 2025 |
| Drumfad Bay Management Company Limited | Extraterritorial | 2006 |
| Drumlin Pharma Services Ltd | Professional & scientific | 2022 |
| Dryas Ecology Ltd | Professional & scientific | 2020 |
| DS Catering Belfast Ltd | Hospitality | 2023 |
| DS Property & Garden Services Ltd | Administrative & support | 2026 |
| DS Supervisory Services Ltd | Professional & scientific | 2010 |
| DSA Solar Limited | Construction | 2025 |
| DSM Motor Group Ltd | Wholesale & retail | 2026 |
| Dsunshine Limited | Wholesale & retail | 2025 |
| DTJ Renewables Limited | Extraterritorial | 2015 |
| Dubb Glass Limited | Wholesale & retail | 2024 |
| Duiniu Limited | Wholesale & retail | 2023 |
| Duncan Rugs & Carpets Ltd | Wholesale & retail | 2023 |
| Dunco Ltd | Construction | 2023 |
| Dundunnyan Ltd | Wholesale & retail | 2025 |
| Dunleath Estates Limited | Agriculture & fishing | 1965 |
| Dunlop Homes Limited | Construction | 1987 |
| Dunville & Co. Limited | Manufacturing | 1975 |
| Dunvullen Caherelly Ltd | Wholesale & retail | 2023 |
| DUR Stone Limited | Wholesale & retail | 2025 |
| Duster Dolls Limited | Administrative & support | 2022 |
| Dwell Solutions Ltd | Real estate | 2016 |
| DWW Consulting Ltd | Other services | 2014 |
| DY Destiny Limited | Health & social care | 2023 |
| Dynamic Synergy Solutions Ltd | Professional & scientific | 2024 |
| E & C Fitzgerald Limited | Construction | 2013 |
| E & H Services Ltd | Wholesale & retail | 2017 |
| E a Blythe & Company Ltd | Manufacturing | 2003 |
| E-Room Property Ltd | Real estate | 2026 |
| E-Studd Ltd | Wholesale & retail | 2025 |
| EA Craig Consulting Ltd | Professional & scientific | 2023 |
| East Coast Day Opportunities Ltd | Health & social care | 2024 |
| Eastend Tanning Ltd | Other services | 2021 |
| Eastleigh Construction (N.I) Ltd | Construction | 2018 |
| Easy Ecom Ltd | Wholesale & retail | 2024 |
| EAT N.I. Ltd | Agriculture & fishing | 2016 |
| Ebell Sobuy Limited | Wholesale & retail | 2025 |
| EBL Global Ltd | Wholesale & retail | 2009 |
| Echlinville Building & Civil Engineering Ltd | Construction | 2023 |
| Echlinville Distillery Limited | Manufacturing | 2004 |
| Echopurgee Ltd | Wholesale & retail | 2025 |
| Ecom Solutions Ltd | Information & communication | 2019 |
| Ecosand Minerals Ltd | Mining & quarrying | 2025 |
| Ecozolobowl Ltd | Wholesale & retail | 2025 |
| Edgar Kudzin Limited | Wholesale & retail | 2025 |
| EDV Team Deverson (N.I.) Limited | Administrative & support | 2022 |
| Edward Craig Ltd | Wholesale & retail | 2025 |
| Eenaway ISE Ltd | Wholesale & retail | 2024 |
| Effective Distribution Ltd | Wholesale & retail | 2023 |
| Effort Chef Products Limited | Wholesale & retail | 2024 |