| Mccabe Family Holdings Ltd | Financial services | 2026 |
| Mccavery Roofing Ltd | Construction | 2012 |
| Mcconnell Healthcare Ltd | Health & social care | 2021 |
| Mccullough Electrics Ltd | Construction | 2019 |
| Mcdermott Coaching Ltd | Health & social care | 2026 |
| MCG Welding Services Limited | Construction | 2013 |
| Mcgall Property Ltd | Real estate | 2022 |
| Mcgrath Bakery Services Ltd | Wholesale & retail | 2007 |
| Mckeefry Rainey Ltd | Arts & recreation | 2025 |
| Mckinley Construction Management Limited | Professional & scientific | 2018 |
| Mcmenamin Poultry Ltd | Other services | 2013 |
| Megarry Bros Limited | Administrative & support | 2018 |
| Megarry Bros Products Ltd | Wholesale & retail | 2021 |
| Merrie Gardens Partnership Limited | Public administration | 2022 |
| MI Masala Limited | Hospitality | 2025 |
| Michael B Mcnulty Ltd | Professional & scientific | 2015 |
| Michael Hutchinson Golf Ltd | Wholesale & retail | 2026 |
| Micon Developments Ltd | Construction | 2021 |
| Migs Healthcare Ltd | Health & social care | 2015 |
| Mills Contracts Civils Ltd | Construction | 2022 |
| Mills Contracts Ltd | Construction | 2000 |
| Millstone Drive Management Company Ltd | Households | 2017 |
| Miniss Ltd | Wholesale & retail | 2024 |
| MJ RAF Consultancy Ltd | Professional & scientific | 2024 |
| MJH Mechanical & Electrical Maintenance Ltd | Manufacturing | 2025 |
| Momentum Humancapital Limited | Professional & scientific | 2013 |
| MON Construction Ltd | Construction | 2018 |
| Montnoir Ltd | Real estate | 2026 |
| Monty Plumbing and Heating Services Ltd | Construction | 2025 |
| Moodfit Ltd | Arts & recreation | 2026 |
| Moonlighting AV (NI) Limited | Arts & recreation | 2024 |
| Morton Properties (Dromore) Ltd | Real estate | 2020 |
| Mossvale (FIC) Ltd | Professional & scientific | 2024 |
| Mossvale Fiduciary Ltd | Financial services | 2025 |
| Mtch Investments Ltd | Financial services | 2026 |
| Mulgrew Haulage Limited | Transport & logistics | 2000 |
| Mulligan Coachworks Ltd | Extraterritorial | 2005 |
| Murray Tipper Hire Ltd | Transport & logistics | 2019 |
| Music Video Marketplace Ltd | Information & communication | 2019 |
| MW Homes Limited | Construction | 2014 |
| MW Power Grid NI Ltd | Professional & scientific | 2026 |
| NAT Fashion Limited | Wholesale & retail | 2025 |
| Naxos Solutions Limited | Hospitality | 2019 |
| Ndigit.Ai Ltd | Information & communication | 2025 |
| Nelson ACC SVS Ltd | Professional & scientific | 2026 |
| New Hope Guinea-Bissau | Other services | 2025 |
| New House Records Ltd | Information & communication | 2022 |
| Newell Offshore Services Ltd | Construction | 2024 |
| Newpark Developments (NW) Ltd | Agriculture & fishing | 2014 |
| Newpark Farms Limited | Agriculture & fishing | 2014 |
| Next Level Thinking Ltd | Professional & scientific | 2025 |
| NI Autosales Ltd | Wholesale & retail | 2023 |
| Nickal Developments Ltd | Construction | 2007 |
| Nickal Holdings Ltd | Financial services | 2021 |
| Nidhi Gupta Ltd | Health & social care | 2014 |
| Nilpig Limited | Financial services | 2021 |
| NJA Contracts Limited | Extraterritorial | 2017 |
| Noel Somerville Building Services Limited | Construction | 2010 |
| Numilo Ltd | Professional & scientific | 2018 |
| OCS Engineering Ltd | Professional & scientific | 2024 |
| OIL Direct Limited | Wholesale & retail | 2011 |
| Optik Project Services Limited | Real estate | 2024 |
| Overhead Door Company Ltd | Construction | 2025 |
| P S Building Contracts Limited | Construction | 2024 |
| Parkgate Property Developments Ltd | Construction | 2021 |
| Parks Family Property Limited | Real estate | 2025 |
| Pathway Business Consulting Limited | Professional & scientific | 2018 |
| Paul Herron Golf Ltd | Information & communication | 2025 |
| Pd(Ni) Holdings Limited | Professional & scientific | 2018 |
| PEH (Plant & Equipment Hire) Limited | Administrative & support | 2018 |
| Pepper (Dromore) Limited | Transport & logistics | 1998 |
| Pepper Architects Ltd | Professional & scientific | 2025 |
| PFS Management Consultants Ltd | Professional & scientific | 2016 |
| Phun's Welcome Ltd | Hospitality | 2026 |
| PJ Plant and Machinery Limited | Administrative & support | 2025 |
| Plant - Tool Hire Ltd | Administrative & support | 2022 |
| Podium Project Management Ltd | Professional & scientific | 2023 |
| Polaris Horizon Ltd | Information & communication | 2021 |
| Porters Accident Repair Centre Ltd | Wholesale & retail | 2023 |
| Portum Capitis Ltd | Professional & scientific | 2020 |
| PR Shutter Specialists Limited | Other services | 2023 |
| Premiair Hvac Ltd | Construction | 2026 |
| Programcmm Ltd | Information & communication | 2013 |
| Progress Energy (NI) Ltd | Water & waste | 2013 |
| Protech Design Consultancy Limited | Administrative & support | 2014 |
| PSM Advisory Ltd | Professional & scientific | 2026 |
| Pulse Hair Ltd | Other services | 2013 |
| Q R Automotive NI Limited | Wholesale & retail | 2025 |
| Q R Autos Ltd | Wholesale & retail | 2022 |
| Quilly Estates Ltd | Real estate | 2023 |
| Quilly Taxis Ltd | Transport & logistics | 2024 |
| Quoile Plant & Civil Contracts Limited | Water & waste | 2021 |
| R. F. Clarke Ltd | Manufacturing | 1956 |
| R.O. Contracts Limited | Construction | 2020 |
| RAH Construction Limited | Construction | 2014 |
| Rahul Gupta Ltd | Health & social care | 2011 |
| Rallou Ltd | Financial services | 2020 |
| Rampart Technologies Limited | Information & communication | 2017 |
| Rasaaz Trading Ltd | Wholesale & retail | 2026 |
| Rath Ltd | Real estate | 2023 |