| Local Offers Limited | Wholesale & retail | 2025 |
| Location Club Landes Ltd | Administrative & support | 2023 |
| Lochside Motor Group Limited | Professional & scientific | 2017 |
| Loghouse (NI) Limited | Wholesale & retail | 2025 |
| Lorco Limited | Real estate | 2014 |
| Lotus Garden Chinese Limited | Hospitality | 2026 |
| Lough Erne Building and Civil Engineering Limited | Construction | 2017 |
| Lough Erne Contracts (NI) Ltd | Construction | 2016 |
| Lough Erne Fairways Limited | Hospitality | 2021 |
| Lough Erne Green Limited | Hospitality | 2021 |
| Lough Erne RIB Safaris Ltd | Administrative & support | 2024 |
| Lough Erne Yacht Club | Arts & recreation | 2010 |
| Lough Navar Farm Ltd | Hospitality | 2025 |
| Lough Shore Development Limited | Construction | 1999 |
| Lough Shore Road Limited | Hospitality | 2014 |
| Loughdooley Holdings Ltd | Financial services | 2026 |
| Lougherne Fishwedding Ltd | Hospitality | 2017 |
| Loughmallard Properties Limited | Real estate | 2008 |
| Loughshore Properties Limited | Real estate | 2014 |
| Loughside Enterprises Ltd | Real estate | 2021 |
| Loughview Property Ltd | Real estate | 2023 |
| Louis Boyd (Earthmoving) Ltd | Construction | 2003 |
| Lous JOO Limited | Wholesale & retail | 2024 |
| LR Tyres Ltd | Wholesale & retail | 2026 |
| Lspa Nails & Spa Ltd | Other services | 2024 |
| Lucky House Lisnaskea Ltd | Hospitality | 2024 |
| Lucky House Newtownbutler Ltd | Hospitality | 2022 |
| Luckypuntcompetitions Ltd | Arts & recreation | 2025 |
| Lumiera Limited | Professional & scientific | 2014 |
| Lunn Developments Limited | Financial services | 2005 |
| Lurgabrack Ltd | Real estate | 2021 |
| LUX Chemicals Ltd | Manufacturing | 2021 |
| Luxdine Limited | Hospitality | 2020 |
| Luxrobes Ltd | Wholesale & retail | 2021 |
| Lydia Enniskillen Ltd | Wholesale & retail | 2024 |
| Lynk Properties Limited | Real estate | 2005 |
| M & E Carters Ltd | Construction | 2019 |
| M & I Contracts Limited | Construction | 2011 |
| M Bunmichael Limited | Financial services | 2024 |
| M H Plant Ltd | Administrative & support | 2011 |
| M Monaghan Construction Ltd | Construction | 2026 |
| M R Wealth Management Ltd | Financial services | 2011 |
| M&D Monaghan Ltd | Education | 2024 |
| M&K Lettings Limited | Real estate | 2024 |
| M&L Motor Sales Ltd | Wholesale & retail | 2024 |
| M&S Tyres Enniskillen Ltd | Wholesale & retail | 2012 |
| M.O.D.Con Building & Civil Engineering Ltd | Construction | 2019 |
| M.P.S.D. Ltd | Real estate | 1999 |
| M.W. CAD Solutions Ltd. | Professional & scientific | 2012 |
| M2F Agri Limited | Agriculture & fishing | 2024 |
| M7 Engineering Limited | Wholesale & retail | 2016 |
| Maccur Limited | Professional & scientific | 2012 |
| Macknagh Media Ltd | Professional & scientific | 2024 |
| Macnean Community Partnership | Other services | 1991 |
| Macneary Rasdale & Co. Ltd | Professional & scientific | 2006 |
| Macplant (N.I.) Ltd | Wholesale & retail | 2002 |
| Madra Properties Ltd | Construction | 2023 |
| MAE Distribution (NI) Limited | Wholesale & retail | 2025 |
| Magcon Engineering Limited | Construction | 2016 |
| Magcost Ltd | Construction | 2024 |
| Magee Brothers Transport Limited | Transport & logistics | 2018 |
| Magtek Limited | Information & communication | 2024 |
| Maguire Foods Ltd | Hospitality | 2015 |
| Maguire Fuels Limited | Wholesale & retail | 2016 |
| Maguire Property Rentals Ltd | Real estate | 2020 |
| Maguire's Bar & Restaurant Ltd | Hospitality | 2026 |
| Mahon World Ltd | Wholesale & retail | 2025 |
| Maichay Limited | Wholesale & retail | 2024 |
| MAK Plant Hire Limited | Administrative & support | 2014 |
| Maker Baking Limited | Wholesale & retail | 2023 |
| Mallard Community Charitable Hub Limited | Hospitality | 2022 |
| Mallard Properties (Number 2) Limited | Real estate | 2014 |
| Mallard Properties Limited | Real estate | 2006 |
| Mana Performance by Jason Hogg Ltd | Arts & recreation | 2025 |
| Manclar Limited | Wholesale & retail | 2020 |
| Mandy Mahon Limited | Real estate | 2003 |
| Mannok Build Holdings Limited | Professional & scientific | 2011 |
| Mannok Pack (NI) Limited | Manufacturing | 2019 |
| Manor Auto Services Limited | Wholesale & retail | 2015 |
| Manor Green Investments Limited | Agriculture & fishing | 2014 |
| Mantlin Trading Ltd | Wholesale & retail | 2019 |
| Marble Arch Enterprises Ltd | Financial services | 2015 |
| Marble Arch Equine Ltd | Arts & recreation | 2015 |
| Marble Arch Health Ltd | Health & social care | 2015 |
| Marble Arch Holdings Ltd | Real estate | 2026 |
| Marcro Services Ltd | Wholesale & retail | 2025 |
| Mardan Poultry Limited | Agriculture & fishing | 2015 |
| Marishop Trading Ltd | Other services | 2022 |
| Mark Brian Gallagher Ltd | Wholesale & retail | 2025 |
| Markhor(Uk) Ltd | Wholesale & retail | 2021 |
| Marmaris UK Barbers Ltd | Other services | 2026 |
| Maroon Clean Ltd | Other services | 2014 |
| Martris Limited | Real estate | 2022 |
| Massabielle Support Ltd | Education | 2025 |
| Master Key Movement | Information & communication | 2021 |
| Matamy Trading Ltd | Other services | 2024 |
| Matdata Ltd | Information & communication | 2026 |
| Matryan Properties Ltd | Real estate | 2005 |
| Mattress.Ie 2025 Ltd | Wholesale & retail | 2025 |
| Mattress.Ie Ltd | Wholesale & retail | 2019 |