| Mount Pleasant Hill Limited | Professional & scientific | 2025 |
| Mouswald Park Limited | Hospitality | 2007 |
| MPC Consultancy Ltd | Health & social care | 2024 |
| MR Fade Barber Dumfries Ltd | Other services | 2025 |
| MR News Convenience Store Limited | Wholesale & retail | 2018 |
| MR Pharm 741 Limited | Wholesale & retail | 2023 |
| MRG Agri Construction Ltd | Agriculture & fishing | 2019 |
| MS Plastering Roughcasting & Rendering Ltd | Extraterritorial | 2026 |
| Munro Welding & Fabrication Ltd | Manufacturing | 2025 |
| Murray Ettle & Associates | Health & social care | 2010 |
| Murraythwaite Limited | Real estate | 2022 |
| MW Solutions (Dumfries) Ltd | Hospitality | 2026 |
| MWB Farms Limited | Agriculture & fishing | 2019 |
| MWL Contracts Limited | Construction | 2016 |
| My Garage Door Limited | Construction | 2023 |
| My Little Calm Space CIC | Health & social care | 2025 |
| MZ & Stone Ltd | Hospitality | 2026 |
| MZ Mart Ltd | Wholesale & retail | 2025 |
| N Henderson Engineering Limited | Manufacturing | 2016 |
| Neart Trading Group Limited | Wholesale & retail | 2023 |
| Nelson Brown Limited | Wholesale & retail | 2010 |
| Nelson the Removal & Storage Company Limited | Transport & logistics | 2002 |
| Neon Cyber Solutions Ltd | Information & communication | 2022 |
| New AGE Endeavour Ltd | Information & communication | 2023 |
| New Cample Bond Ltd | Wholesale & retail | 2023 |
| New Fortune House Ltd | Hospitality | 2026 |
| New Gurkha Kitchen Ltd | Hospitality | 2026 |
| New Scots Limited | Information & communication | 2026 |
| New Sunman Ltd | Hospitality | 2023 |
| Newhouse Farming Limited | Agriculture & fishing | 2018 |
| Newlands Farms and Forestry Limited | Real estate | 2010 |
| Nexgendt Ltd | Education | 2023 |
| Nextgen Vision (Scot) Ltd | Other services | 2024 |
| NG Bubbles Ltd | Administrative & support | 2024 |
| Nich Limited | Professional & scientific | 2004 |
| Nictom Letting Limited | Real estate | 2025 |
| Niki Whannel Properties Limited | Real estate | 2018 |
| Ninetwofive Engineering Ltd | Professional & scientific | 2017 |
| Ninety-Six Testing Limited | Information & communication | 2012 |
| Nith Catchment Fishery Trust | Agriculture & fishing | 2009 |
| Nith River Brazilian JIU Jitsu Ltd | Education | 2024 |
| Nith Valley Cleaning Services Limited | Other services | 2016 |
| Nith Valley Construction Limited | Construction | 2002 |
| Nithbank Ltd | Health & social care | 2023 |
| Nithcree Training Services Limited | Education | 2004 |
| Nithsdale Amateur Rowing Club Limited | Arts & recreation | 2010 |
| Nithsdale Firewood Ltd | Agriculture & fishing | 2022 |
| Nithsdale Foods Limited | Wholesale & retail | 2018 |
| Nithsdale Plumbing & Heating Limited | Construction | 2013 |
| Nithsdale Property Services Ltd | Construction | 2024 |
| Nithsdale Safety Ltd | Professional & scientific | 2023 |
| Nithsdale Trading Limited | Real estate | 2014 |
| Noble House Designs Limited | Real estate | 2002 |
| Norman Furnishings Limited | Wholesale & retail | 2007 |
| Norquoy Autos Limited | Wholesale & retail | 2024 |
| North East Fallen Stock Ltd | Extraterritorial | 2012 |
| Northtech Construction Limited | Wholesale & retail | 2005 |
| Northview Customs & Autoglazing Ltd | Wholesale & retail | 2018 |
| NOW Scotland Limited | Other services | 2021 |
| NSM Farms Limited | Real estate | 2017 |
| NTD Photography Ltd | Professional & scientific | 2013 |
| Ntst Trading Ltd | Wholesale & retail | 2025 |
| Nunholm Farming Company | | 1978 |
| Nurture Tots Ltd | Education | 2023 |
| Nythva Ltd | Financial services | 1975 |
| Oakbank Contract Services Limited | Construction | 2018 |
| Oakbank Plant Hire Limited | Administrative & support | 2017 |
| Oakbank Waste Management Limited | Manufacturing | 2013 |
| Oasis WET & DRY Limited | Hospitality | 2014 |
| Oceanallover | Arts & recreation | 1997 |
| Ohmega Technical Solutions Limited | Professional & scientific | 2007 |
| Okhrewood Developments Limited | Construction | 2025 |
| OM SAI Kripa Ltd | Health & social care | 2017 |
| ON Board Training Driving Academy Ltd | Education | 2025 |
| ON Board Training Limited | Education | 2018 |
| One Scotland Many Cultures Limited | Education | 2012 |
| Orimson Ltd | Professional & scientific | 2025 |
| Orsi Consulting Ltd | Professional & scientific | 2025 |
| Oupa Ltd | Real estate | 2026 |
| Ouroboros Festival Services Limited | Water & waste | 2026 |
| Outertown Energies Limited | Energy | 2015 |
| Outertown Limited | Agriculture & fishing | 2023 |
| OWL Redeemer Ltd | Hospitality | 2014 |
| P Kenyon Celebrants Limited | Other services | 2024 |
| P.S.Ridgway Limited | Transport & logistics | 1976 |
| Pacora Ltd | Manufacturing | 2025 |
| Padri's Ltd | Hospitality | 2025 |
| Paine Free Crafts Ltd | Wholesale & retail | 2020 |
| PAL Dog Walking Pet Minding Limited | Agriculture & fishing | 2025 |
| PAN and Plate Ltd | Hospitality | 2024 |
| Papa Rabs Limited | Hospitality | 2017 |
| Parc Construction Ltd | Construction | 2022 |
| Parkdale Garage Limited | Wholesale & retail | 2001 |
| Parkdale Holdings Ltd | Financial services | 2021 |
| Parkdale Motorstore Ltd | Extraterritorial | 2023 |
| Parkgate Holdings Limited | Agriculture & fishing | 2004 |
| Partworks UK Ltd | Manufacturing | 2025 |
| Pasta Pronta Limited | Hospitality | 2001 |
| Path to Success Consultants Dumfries Ltd | Information & communication | 2025 |
| Path to Success Consultants Ltd | Wholesale & retail | 2021 |