| G&K Contracts Ltd. | Construction | 2013 |
| G&P Coleman LLP | | 2024 |
| Gaelú Ltd | Wholesale & retail | 2025 |
| Garden Room Sales Limited | Construction | 2021 |
| Garnock Investments Limited | Other services | 1993 |
| Garvagh Dental Ltd | Health & social care | 2015 |
| Gate Lodge Fuels & Country Store Ltd | Wholesale & retail | 2018 |
| GEM Residential Ltd | Construction | 2002 |
| George L. Glover & SON, Limited | Agriculture & fishing | 1951 |
| Geotick Ltd | Construction | 2021 |
| Gerard Scullion Architects Limited | Professional & scientific | 2016 |
| GF Joinery Contracts Ltd | Manufacturing | 2023 |
| GID Accounting Limited | Professional & scientific | 2022 |
| Gilchrist Meadows Property Management Limited | Households | 2025 |
| Gilmour Commissioning Management Ltd | Professional & scientific | 2024 |
| GJG Creative Consultants Limited | Construction | 2019 |
| GL Promotions Ltd | Professional & scientific | 2026 |
| Glassagh Property Ltd | Construction | 2020 |
| Glenbrook Stud Limited | Agriculture & fishing | 2012 |
| Glencar Veterinary Care Limited | Professional & scientific | 2023 |
| Glengom Roofing Services Ltd | Construction | 2025 |
| Glenmaquill Limited | Professional & scientific | 2026 |
| Glenviggan Construction Ltd | Construction | 2017 |
| Glenvilla Ultimate Dryers Limited | Manufacturing | 2015 |
| Global Goods Sourcing Ltd | Wholesale & retail | 2025 |
| Glór Mhachaire Fíolta | Education | 2024 |
| GMB Services (NI) Limited | Construction | 2013 |
| Gmsol Service Limited | Professional & scientific | 2015 |
| Golden City BT45 Limited | Hospitality | 2024 |
| Golden Gate 2026 Ltd | Hospitality | 2026 |
| Golden Gate Magherafelt Ltd | Hospitality | 2022 |
| Goodsaroo Ltd | Wholesale & retail | 2025 |
| Gordon Bell & SON Ltd | Wholesale & retail | 2021 |
| Gordon Stuart Trust Limited | Professional & scientific | 2016 |
| Gortanewry Farm Ltd | Wholesale & retail | 2025 |
| Gorttobair Ltd | Other services | 2026 |
| Gracefield Agricultural Supplies Ltd | Wholesale & retail | 2024 |
| Gracelands Glamping Limited | Hospitality | 2021 |
| Grant Plant and Construction Limited | Construction | 2008 |
| Green Airé IRL Ltd | Professional & scientific | 2022 |
| Green Wind Energy Ltd | Energy | 2011 |
| Greengage Close Management Company Limited | Households | 2022 |
| Greer's Tyre Services Ltd | Wholesale & retail | 2011 |
| Grenane Properties Limited | Construction | 2005 |
| Greyhill Holdings Ltd | Agriculture & fishing | 2024 |
| Ground Kontrol Ltd | Manufacturing | 2024 |
| Groundforce 1 Civil Engineers & Plant Hire Ltd | Construction | 2022 |
| Grove Builders Ltd | Construction | 2004 |
| Growin CIC | Professional & scientific | 2026 |
| GS Plumbing & Heating (N.I.) Limited | Construction | 2016 |
| GSM Financial Services Ltd | Financial services | 2022 |
| GT Inns Ltd | Hospitality | 2004 |
| Gym PAL Ltd | Education | 2019 |
| H & Y Millar Haulage Ltd | Transport & logistics | 2014 |
| H Armstrong & Associates Ltd | Professional & scientific | 2015 |
| H Armstrong Limited | Professional & scientific | 2015 |
| H Group Ventures Ltd | Hospitality | 2025 |
| H&A Group Limited | Financial services | 2015 |
| H&A Screen Ltd | Extraterritorial | 2013 |
| H.J. Downey Ltd | Hospitality | 1997 |
| Hair Loss Rehab Magherafelt Ltd | Other services | 2025 |
| HAJ Group (N.I.) Limited | Wholesale & retail | 2017 |
| Hampsey Consultants Ltd | Construction | 2020 |
| Hancock Properties (NI) Ltd | Extraterritorial | 2011 |
| Happy Days (Magherafelt) Ltd | Other services | 2004 |
| Harkin Homes Ltd | Real estate | 2026 |
| Harriet Kitson Wills & Estates Limited | Professional & scientific | 2022 |
| Hatch Brothers Limited | Manufacturing | 2016 |
| Hatton Consultancy (N.I.) Ltd | Professional & scientific | 2017 |
| Hazel Drive Company Limited | Financial services | 2019 |
| Hazeldene Enterprises Limited | Arts & recreation | 2010 |
| HE Yang Limited | Wholesale & retail | 2024 |
| Healing the Land Limited | Other services | 2017 |
| Healthy Building LAB Ltd | Information & communication | 2026 |
| Heaney Brewing Company Limited | Manufacturing | 2016 |
| Helicon Equipment Ltd | Manufacturing | 2025 |
| Henry and Teresa Mcglone (Dorman's Bar) Ltd | Hospitality | 2014 |
| Henry and Teresa Mcglone (Mary's Bar) Ltd | Hospitality | 2014 |
| Henry Brothers Construction Limited | Construction | 2015 |
| Henry Brothers Limited | Construction | 2015 |
| Henry Brothers Property Limited | Real estate | 2019 |
| Heron Countesswell (NO. 3) Limited | Construction | 2013 |
| Heron Energy Limited | Energy | 2023 |
| Heron Fiduciary Services Limited | Financial services | 2026 |
| Heron Fire Solutions Limited | Construction | 2024 |
| Heron Oughtboy Limited | Energy | 2024 |
| Heron Power Limited | Energy | 2018 |
| Heron Property NO 1 Limited | Construction | 2020 |
| Heron Storage Development Limited | Energy | 2026 |
| Heron Storage NO. 2 Limited | Energy | 2024 |
| Heron Storage NO. 3 Limited | Energy | 2025 |
| Heron Storage NO. 4 Limited | Energy | 2025 |
| Heron Storage NO. 5 Limited | Energy | 2026 |
| Heron Storage NO. 6 Limited | Energy | 2026 |
| Heron Storage NO. 7 Limited | Energy | 2026 |
| Heron Wind Limited | Energy | 2024 |
| HEX Software Ltd | Information & communication | 2024 |
| Higgins Haulage & Pallet Sales Ltd | Transport & logistics | 2025 |
| High & DRY Products Limited | Wholesale & retail | 2026 |
| Hillhead Plant & Haulage Ltd | Construction | 2017 |