| Digital Worldwide Trading Ltd | Wholesale & retail | 2021 |
| DIGITAL54 Ltd | Information & communication | 2018 |
| Digitalarc Limited | Extraterritorial | 2024 |
| Digitall IT Solutions Ltd | Wholesale & retail | 2019 |
| Digitaltwentyfour Limited | Information & communication | 2015 |
| Dillon Bass Limited | Wholesale & retail | 1978 |
| Dilly and Dolly’S 2021 Ltd | Hospitality | 2021 |
| DIM SUM Library Limited | Hospitality | 2016 |
| Dime Asset Management Company Limited | Households | 1985 |
| Dimei Petpal Limited | Wholesale & retail | 2025 |
| Dimension Consulting Ltd | Information & communication | 2024 |
| Dimensions Design & Management Limited | Construction | 2003 |
| Dimensions Property Development Limited | Real estate | 2006 |
| Dimi Sound Design Services Limited | Information & communication | 2020 |
| Dina 38 Ltd | Other services | 2023 |
| Ding Victory Limited | Wholesale & retail | 2024 |
| Dinlan Limited | Wholesale & retail | 2024 |
| Dinosaur Developments Ltd | Real estate | 2016 |
| Diocese of Down and Connor Trustee | Administrative & support | 2006 |
| Dionix Ltd | Wholesale & retail | 2025 |
| DIP WU Limited | Real estate | 2024 |
| Dipsomania Ltd | Hospitality | 2024 |
| Direct Change Ltd | Information & communication | 2025 |
| Direct Cremations N.I. Ltd | Other services | 2026 |
| Direct Floor Fitting Limited | Construction | 2013 |
| Direct Mechanical Services (2026) Ltd | Construction | 2026 |
| Direct Medics Ltd | Administrative & support | 2000 |
| Direct Payment Solutions CIC | Information & communication | 2023 |
| Direct Service Renovations Ltd | Manufacturing | 2026 |
| Direct Vape NI Limited | Wholesale & retail | 2024 |
| Direct Wholesale Partners Ltd | Wholesale & retail | 2025 |
| Directclean Supplies Ltd | Administrative & support | 2025 |
| Director Management Ltd | Extraterritorial | 1997 |
| Directorship and Secretary Service Ltd | Information & communication | 2020 |
| Dirnan Properties Ltd | Real estate | 2013 |
| Dirtbird Limited | Hospitality | 2018 |
| Dirty Harrys Launderette Ltd | Other services | 2025 |
| Disability Action (NI) | Professional & scientific | 1986 |
| Disability Action (NI) Employment & Training | Administrative & support | 1987 |
| Disability Sport NI Ltd | Arts & recreation | 1997 |
| Disabled Police Officers Association of Northern Ireland | Other services | 2002 |
| Disaforta Limited | Construction | 2023 |
| Disconation Limited | Wholesale & retail | 2025 |
| Discount Blinds Limited | Manufacturing | 2005 |
| Discount Furnishings Limited | Wholesale & retail | 2018 |
| Discourse Miniatures Limited | Information & communication | 2022 |
| Discoworks Limited | Arts & recreation | 2024 |
| Displaynote Technologies Limited | Information & communication | 2011 |
| Disruption Limited | Education | 2024 |
| Distbo Coning Limited | Wholesale & retail | 2025 |
| Distil Recruitment Limited | Administrative & support | 2016 |
| Distinguished Homes Ltd | Construction | 2022 |
| Distinguished Homes Management Limited | Construction | 2023 |
| Distribute Good Ltd | Administrative & support | 2024 |
| District Coffee (Belfast) Limited | Hospitality | 2018 |
| District Coffee (N.I.) Limited | Hospitality | 2016 |
| Dita Primerent Ltd | Real estate | 2025 |
| Ditbot Ltd | Information & communication | 2025 |
| Divergent Training & Coaching Ltd | Health & social care | 2025 |
| Diverse Stars Limited | Wholesale & retail | 2024 |
| Diverse Talent Careers Ltd | Administrative & support | 2020 |
| Diverse Youth NI Ltd | Education | 2022 |
| Diversion Ventures Limited | Wholesale & retail | 2025 |
| Diversity (NI) Limited | Professional & scientific | 2010 |
| Diversity and Integration Initiative Limited | Education | 2013 |
| Divine Mandate Ltd | Health & social care | 2023 |
| Divine Pets Limited | Wholesale & retail | 2020 |
| Divis Developments Limited | Financial services | 1984 |
| Dixell Investments Limited | Construction | 2014 |
| Dixon & Company (Coleraine) Limited | Real estate | 1963 |
| Dixon Tutoring Limited | Education | 2025 |
| DIY Splashbacks Ltd | Other services | 2015 |
| DIY4U (NI) Ltd | Wholesale & retail | 2013 |
| DJ Collins Ltd | Financial services | 2025 |
| DJ Warehouse Ltd | Wholesale & retail | 2015 |
| DJB (N.I.) Ltd | Hospitality | 2024 |
| DJB Directors Limited | Professional & scientific | 2016 |
| Djcj Properties Limited | Real estate | 2024 |
| DJD Ltd | Construction | 2018 |
| Djinn Digital Ltd | Information & communication | 2020 |
| DJJ Coaching Limited | Arts & recreation | 2025 |
| DJK International Ltd | Wholesale & retail | 2020 |
| Djlb Properties Limited | Real estate | 2016 |
| Djlb Property Management Co Ltd | Households | 2026 |
| Djlewis Recycling Ltd | Water & waste | 2024 |
| Djmck Property Rentals Ltd | Real estate | 2022 |
| Djmv Limited | Wholesale & retail | 2022 |
| Djmygod Ltd | Wholesale & retail | 2024 |
| DJS Enterprises Ltd | Hospitality | 2019 |
| DJS Legal Ltd | Professional & scientific | 2019 |
| DJS Venture Ltd | Financial services | 2025 |
| Djsal Ltd | Hospitality | 2017 |
| DJV Compliance Ltd | Water & waste | 2014 |
| DK Promotions Ltd | Arts & recreation | 2016 |
| DK Simulations Ltd | Information & communication | 2012 |
| Dkelly Limited | Arts & recreation | 2023 |
| DKH Legal Tech Consulting Limited | Information & communication | 2023 |
| DKN Belfast Ltd | Hospitality | 2025 |
| Dktohsl Ltd | Real estate | 2022 |
| DL Aerospace Ltd | Manufacturing | 2018 |