| 25DG Ltd | Real estate | 2021 |
| 7EVN Limited | Wholesale & retail | 2025 |
| 811 Management Limited | Real estate | 2015 |
| A Murray Ltd | Wholesale & retail | 2018 |
| A&B Doors Limited | Other services | 2005 |
| AB Quinn Holdings Ltd | Construction | 2022 |
| Abbey 1144 Limited | Real estate | 2017 |
| AC Rice Contracts Ltd | Construction | 2014 |
| AGD Plumbing & Heating Ltd | Construction | 2017 |
| Always Forward Nutrition Ltd | Hospitality | 2025 |
| Amatanning Ltd | Other services | 2026 |
| AMG CA Ltd | Professional & scientific | 2024 |
| Anacor Ltd | Real estate | 2012 |
| ANT Node Limited | Professional & scientific | 2025 |
| AO Accountancy & Consultancy Services Ltd | Professional & scientific | 2015 |
| Archaeology and Heritage Consultancy Ltd | Professional & scientific | 2014 |
| Ardnabannon House Ltd | Arts & recreation | 2025 |
| Ashview Consultants Ltd | Other services | 2013 |
| Ashwood Transport Ltd | Transport & logistics | 2019 |
| Assured Wind Energy Ltd | Energy | 2020 |
| ATB Tiling Ltd | Construction | 2018 |
| Aughacullion Limited | Professional & scientific | 2019 |
| Aughlisnafin Community Association | Arts & recreation | 2013 |
| Aura Safety Management Ltd | Administrative & support | 2025 |
| B Mcveigh Mechanical Ltd | Construction | 2026 |
| B R Building & Joinery Limited | Construction | 2014 |
| Ballylough Construction Ltd | Construction | 2005 |
| Ballylough Consultancy Solutions Limited | Professional & scientific | 2018 |
| Ballylough Enterprises Limited | Real estate | 1981 |
| Ballylough Stud Limited | Agriculture & fishing | 2025 |
| Ballyward Hall Management Company Ltd | Arts & recreation | 2013 |
| Ballyward Plant Services Ltd | Wholesale & retail | 2014 |
| Ballyward Plant Supplies Ltd | Wholesale & retail | 2017 |
| Barrs Contracts Ltd | Construction | 2024 |
| Barry Mccrickard Joinery Limited | Construction | 2018 |
| Bbess Ltd | Energy | 2023 |
| BC Park Limited | Hospitality | 2018 |
| BDK Holdings Ltd | Real estate | 2024 |
| Beauty on the Square Academy Ltd | Other services | 2026 |
| Bell Motor Repairs Ltd | Wholesale & retail | 2026 |
| Bemac Joinery Ltd | Construction | 2019 |
| Bfrp Ltd | Construction | 2020 |
| BGR (NI) Limited | Professional & scientific | 2014 |
| Bikelab Retail Ltd | Wholesale & retail | 2026 |
| Bkkb Properties Limited | Real estate | 2024 |
| Blue FIN Software Solutions Limited | Information & communication | 2015 |
| Bluewire Management Limited | Real estate | 2012 |
| Bmac Services Ltd | Construction | 2017 |
| BMC Fabrication Ltd | Manufacturing | 2025 |
| Brettson Ltd | Arts & recreation | 2020 |
| Brown Brothers Ballylough Ltd | Agriculture & fishing | 2016 |
| Buffer Apartments Management Company Limited | Households | 2004 |
| Burrenbridge Community Group | Other services | 2012 |
| Burrenbridge Holdings Ltd | Information & communication | 2023 |
| C Kane Plumbing & Heating Ltd | Construction | 2017 |
| C Quinn Bricklaying Ltd | Construction | 2017 |
| C Rice Developments Ltd | Construction | 2025 |
| C.M Butchers Ltd | Wholesale & retail | 2022 |
| Callana Holdings Ltd | Financial services | 2022 |
| Carnpark Farms Limited | Agriculture & fishing | 2020 |
| Carpe Diem 13 Limited | Financial services | 2025 |
| Cast Build Limited | Construction | 2015 |
| Cast Property (IRE) Limited | Real estate | 2016 |
| Castle Glen Kitchens Ltd | Manufacturing | 2012 |
| Castle Green (N.I.) Ltd | Wholesale & retail | 2019 |
| Castle Green International Ltd | Wholesale & retail | 2025 |
| Castle Hill Services Company (NI) Ltd | Extraterritorial | 2006 |
| Castlewellan Community Partnership | Administrative & support | 2019 |
| Castlewellan Community Playgroup | Health & social care | 2007 |
| Castlewellan Regeneration Limited | Other services | 1993 |
| CB Carpentry Ltd | Construction | 2016 |
| CEA Joinery Ltd | Construction | 2026 |
| CFI Training Ltd | Arts & recreation | 2024 |
| Chatterbox (NI) Ltd | Administrative & support | 2005 |
| Chatterbox Holdings Limited | Financial services | 2018 |
| Children's Lane Childcare Ltd | Health & social care | 2019 |
| Cisco Plumbing & Heating Ltd | Construction | 2026 |
| Clan Construction Limited | Construction | 2006 |
| Claragh Bridge Vintage Club | Arts & recreation | 2007 |
| Clonkeel Joinery Ltd | Construction | 2025 |
| Cloverley Hall Limited | | 1994 |
| CMC Shuttering Ltd | Construction | 2017 |
| CMC Surfacing & Groundwork Ltd | Construction | 2025 |
| Coffeelicious Ltd | Hospitality | 2017 |
| Coniash Limited | Real estate | 2024 |
| Construction Sealants (Ireland) Ltd | Construction | 2016 |
| Container Concepts NI Ltd | Construction | 2024 |
| Cooley Spring Water Ltd | Extraterritorial | 2011 |
| Cooley Water Ltd | Extraterritorial | 2011 |
| Corc Property Ltd | Real estate | 2025 |
| Corn Ltd | Real estate | 2014 |
| Corriewood Developments Ltd | Real estate | 2019 |
| Corriewood Estates (N.I.) Limited | Real estate | 2016 |
| Corriewood Holdings Limited | Financial services | 2016 |
| Corriewood Lodge Ltd | Health & social care | 2010 |
| Corriewood Private Clinic Limited | Health & social care | 2009 |
| Creation T/A Simply Mourne Ltd | Arts & recreation | 2024 |
| Creative Energy Consulting Ltd | Information & communication | 2021 |
| Croob Engineering Ltd | Manufacturing | 2016 |
| Cunningham Bros Limited | Other services | 2023 |