| Lisdalgan Properties Limited | Construction | 2011 |
| Lisowen Quantity Surveying Limited | Professional & scientific | 2025 |
| Live Life Social Enterprises Limited | Health & social care | 2021 |
| LKB Construction Limited | Construction | 2003 |
| LNM Healthcare Services Ltd | Health & social care | 2023 |
| Lofi Live Ltd | Information & communication | 2026 |
| Luxuryhouse Rice Ltd | Hospitality | 2025 |
| LWH Supplies Ltd | Wholesale & retail | 2024 |
| M & M Engineering Ltd | Professional & scientific | 2024 |
| M Care Limited | Health & social care | 1999 |
| M Construction N.I Limited | Construction | 2000 |
| M E Rebuild Ltd | Real estate | 2007 |
| M Recovery Ltd | Wholesale & retail | 2019 |
| Machinery Breakers NI Ltd | Water & waste | 2025 |
| Madly Merch Ltd | Manufacturing | 2021 |
| Magheralone Energy Limited | Energy | 2016 |
| Maguire Associates Limited | Professional & scientific | 2016 |
| Maguire Contracts Limited | Construction | 2018 |
| Maje Holdings Ltd | Real estate | 2025 |
| Masseys of Saintfield Limited | Wholesale & retail | 2010 |
| Masterplan Technology Limited | Information & communication | 2024 |
| Maurice Walsh & Company Limited | Manufacturing | 1978 |
| Mayid Properties Ltd | Real estate | 2023 |
| MCB Electrical-Ni Ltd | Construction | 2013 |
| Mcgillan Jones Associates Ltd | Mining & quarrying | 2019 |
| Mckelvey Agri Limited | Agriculture & fishing | 2026 |
| Mclernon Computers (N.I.) Limited | Information & communication | 1990 |
| Mclernons Limited | Professional & scientific | 1990 |
| Mcveigh Accident Repair Centre Limited | Wholesale & retail | 2019 |
| Meraki 2000 Limited | Hospitality | 2024 |
| Millbank Farm Shop Ltd | Wholesale & retail | 2021 |
| Millred Limited | Administrative & support | 2006 |
| Mills Cross Ltd | Professional & scientific | 2024 |
| ML Sales Ltd | Wholesale & retail | 2019 |
| MLS Design Limited | Construction | 1997 |
| MML Rentals Ltd | Real estate | 2025 |
| Mobile Menders Ltd | Wholesale & retail | 2024 |
| Montalto Consulting Ltd | Professional & scientific | 2015 |
| Montalto Properties Limited | Wholesale & retail | 1999 |
| Monteith Interiors Ltd | Wholesale & retail | 2016 |
| Morgan & Brown Property Ltd | Real estate | 2024 |
| Morgan Joinery (Northern Ireland) Ltd. | Construction | 2023 |
| Morton Grab Hire Ltd | Water & waste | 2018 |
| Mossvale Showjumps Limited | Arts & recreation | 2007 |
| Motor & Sport (Ballynahinch) Limited | Wholesale & retail | 1975 |
| Motor Trade Tools Ltd | Wholesale & retail | 2015 |
| Mourne Agencies Ltd | Wholesale & retail | 2006 |
| MTM N.I. Ltd | Manufacturing | 2015 |
| Mullyneill Properties Limited | Real estate | 2023 |
| My Physio N.I Ltd | Other services | 2021 |
| Nailshigh Ltd | Other services | 2025 |
| NDD Nails Ltd | Other services | 2025 |
| Needaco Holdings Limited | Financial services | 2024 |
| Needaco Limited | Health & social care | 1994 |
| Neela NIL Private Company NI Ltd | Hospitality | 2023 |
| Nefarious Arcade Ltd | Wholesale & retail | 2021 |
| New Plate Developments Ltd | Real estate | 2024 |
| Newtown Property Limited | Hospitality | 2017 |
| Nextgen Sims Ltd | Arts & recreation | 2025 |
| NGG Newcastle Ltd | Arts & recreation | 2026 |
| NI Couriers Direct Ltd | Transport & logistics | 2018 |
| NI Engineering Ltd | Manufacturing | 2019 |
| NJB Mechanical Services Ltd | Wholesale & retail | 2026 |
| Norman Elliott and Company Limited | Real estate | 1987 |
| Norman Elliott Digital Accounting Limited | Information & communication | 2019 |
| Northern Ireland Prison Service Sports and Leisure Ltd | Arts & recreation | 2009 |
| NSR Property Living Limited | Real estate | 2025 |
| Oak MAN Ltd | Administrative & support | 2017 |
| Oakdale Environmental Ltd | Professional & scientific | 2024 |
| Ocean Treasure Limited | Financial services | 2011 |
| Oclconsulting Ltd | Information & communication | 2022 |
| Omas Media Ltd | Information & communication | 2009 |
| One T One S Ltd | Real estate | 2022 |
| Online Driver Training Limited | Education | 2024 |
| Open Mind Coaching and Consulting Ltd | Professional & scientific | 2023 |
| Orienture Health Limited | Health & social care | 2026 |
| Orlock Developments Ltd | Construction | 2022 |
| Orlock Homes Ltd | Extraterritorial | 1999 |
| Orlock Limited | Agriculture & fishing | 1987 |
| Orlock Rentals Ltd | Real estate | 2022 |
| Outsource Asset Management Limited | Construction | 2013 |
| P M Girvan Limited | Professional & scientific | 2026 |
| Paddington's Little Treasures Limited | Health & social care | 2023 |
| Pale Mountain Limited | Financial services | 2025 |
| Paragon Fitness (Temple) Ltd | Arts & recreation | 2022 |
| Paragon Team Training Ltd | Arts & recreation | 2022 |
| Patterson Accident Repair Centre Ltd | Wholesale & retail | 2022 |
| Paul Littler Television Cameraman Ltd | Information & communication | 2015 |
| Paul Mcmullan Ltd | Professional & scientific | 2015 |
| PEG SW Solar Bidco Limited | Financial services | 2026 |
| Peking Garden Ballynahinch Ltd | Hospitality | 2024 |
| Pet Education Training Solutions Ltd | Agriculture & fishing | 2015 |
| Peter MAY Consulting Ltd | Professional & scientific | 2024 |
| Peter Mcbride Consultancy Ltd | Professional & scientific | 2019 |
| PFM Events Ltd | Education | 2023 |
| Pharmulate Ltd | Manufacturing | 2024 |
| Pistis Holdings Limited | Wholesale & retail | 2022 |
| Pizzarellys Restaurant Limited | Hospitality | 1988 |
| Portadown Soft Play Limited | Hospitality | 2025 |
| Poseidon Composites Limited | Manufacturing | 2019 |