| Marshal Security Services Ltd | Administrative & support | 2024 |
| Marshall Scott Legal Ltd | Professional & scientific | 2025 |
| Martin Access Resources Ltd | Professional & scientific | 2018 |
| Martin Daly Builders Ltd | Construction | 2019 |
| Maryluk Ltd | Transport & logistics | 2025 |
| Massage & Skin Therapy Limited | Other services | 2026 |
| Master of Cleaning Limited | Administrative & support | 2017 |
| Matchless Energy Group Limited | Construction | 2020 |
| Matthews Elite Construction Ltd | Construction | 2020 |
| Maxalula Properties Ltd | Real estate | 2008 |
| Maxassist Fleet Management Ltd | Wholesale & retail | 2024 |
| Maxum Investments Limited | Real estate | 2001 |
| Maxwelltransportsolutions Ltd | Transport & logistics | 2025 |
| Mayberry Properties Limited | Real estate | 2014 |
| MB Engineering Services Limited | Construction | 1966 |
| MB Glass Partitions Ltd | Construction | 2018 |
| Mbak Properties Ltd | Real estate | 2023 |
| MBD Installations Ltd | Construction | 2023 |
| MBS Bankwood Limited | Construction | 2008 |
| MC Costruction Ltd | Construction | 2024 |
| MC Facades Ltd | Construction | 2018 |
| MC Strong Dental Holdings Limited | Financial services | 2025 |
| Mcadams Transport Ltd | Transport & logistics | 2015 |
| Mcallister & Considine Ltd. | Other services | 2001 |
| Mccann Projects LLP | | 2022 |
| Mccormick Grips Ltd | Other services | 2018 |
| Mcculloch Plumbing & GAS Ltd | Construction | 2025 |
| Mcdade Properties Ltd | Real estate | 2024 |
| Mcdermid Controls Ltd | Manufacturing | 2007 |
| Mcdonald Drivers Ltd | Transport & logistics | 2025 |
| MCE EOT Ltd | Financial services | 2023 |
| MCE Group Holdings Ltd | Financial services | 2015 |
| MCE Maintenance Ltd | Construction | 2015 |
| Mcgavock Consultancy Ltd | Construction | 2020 |
| Mcgeough Building & Civil Engineering Ltd | Construction | 2012 |
| Mcglad Flooring Ltd | Construction | 2023 |
| Mcgraths Limestone UK Limited | Mining & quarrying | 2019 |
| Mcguire Electrical Services Limited | Construction | 2008 |
| Mchugh, Madden and Shaw Limited | Wholesale & retail | 2018 |
| Mcintyre Roofing (Scotland) Limited | Construction | 2024 |
| Mcish Ltd | Manufacturing | 2025 |
| MCK3 Limited | Manufacturing | 2016 |
| Mckee Family Property Limited | Real estate | 2024 |
| Mckeever (Motherwell) Limited | Administrative & support | 2017 |
| Mckenzie Kitchen Installations Limited | Construction | 2013 |
| Mckinley Meats Limited | Hospitality | 2017 |
| Mclachlan Investment Group Ltd | Professional & scientific | 2019 |
| Mclanachan Holdings Limited | Financial services | 2022 |
| Mclanachan Properties Limited | Real estate | 2023 |
| Mclanachan Transport Limited | Transport & logistics | 1984 |
| Mclauchlin Trading Ltd | Real estate | 2022 |
| Mclean Entertainment Ltd | Wholesale & retail | 2019 |
| Mcmanus and Scott Holytown Limited | Health & social care | 2014 |
| Mcmanus and Scott Newarthill Limited | Extraterritorial | 2014 |
| Mcme Capital Ltd | Extraterritorial | 2019 |
| Mcmeechan Holding Ltd | Construction | 2021 |
| Mcmillan Property Group Ltd | Construction | 2025 |
| MCN Airdrie Ltd | Other services | 2021 |
| MCN Hamilton Holdings Ltd | Real estate | 2015 |
| MCP Scotland Ltd | Construction | 2022 |
| Mcpake Truck & Trailer Services Ltd | Professional & scientific | 2020 |
| Mcphabbs Ltd | Hospitality | 2019 |
| Mcphee Bros (Blantyre) Limited | Manufacturing | 1983 |
| MCR (Scotland) Limited | Construction | 2015 |
| MCS Dental Limited | Health & social care | 2022 |
| MCS Entertainers Ltd | Arts & recreation | 2018 |
| MD Trucking Ltd | Transport & logistics | 2024 |
| MDA Energy Holdings Limited | Professional & scientific | 2023 |
| Meauto Ltd | Wholesale & retail | 2025 |
| Mechnrg Ltd | Construction | 2023 |
| Medennium Inc Limited | Wholesale & retail | 2025 |
| Medication Alignment Ltd | Education | 2013 |
| Medzilla Ltd | Professional & scientific | 2020 |
| Meekison Electrical Ltd | Construction | 2025 |
| Megans Nail Space Ltd | Other services | 2025 |
| MEL 3 Limited | Real estate | 2022 |
| MEL 4 Energy Storage Limited | Energy | 2023 |
| MEL 5 ES Limited | Energy | 2024 |
| MEL 5 WF Limited | Energy | 2024 |
| MEL 7 ES Limited | Energy | 2025 |
| MEL 7 WF Limited | Energy | 2025 |
| MEL Cosec Ltd | Professional & scientific | 2019 |
| MEL Nominee Ltd | Administrative & support | 2021 |
| MEL WWS Limited | Professional & scientific | 2017 |
| Melrose Electrical Services Ltd. | Construction | 2014 |
| Meraki Group Management Ltd | Administrative & support | 2023 |
| Meridian Offices Ltd | Administrative & support | 2024 |
| Merumhor Ltd | Wholesale & retail | 2014 |
| Mespil Management Ltd | Professional & scientific | 2025 |
| MF Kitchens & Joinery Ltd | Construction | 2020 |
| MF Renewables Heating and Plumbing Ltd | Construction | 2023 |
| MFS Traders Ltd | Wholesale & retail | 2026 |
| MG Double Glazing Limited | Manufacturing | 2023 |
| Mgcproperty Ltd | Real estate | 2021 |
| MGL Landscapes Limited | Construction | 2024 |
| Mgla Productions Ltd | Information & communication | 2015 |
| MGM Electrical Scotland Ltd | Construction | 2024 |
| MGQ Aesthetics and Beauty Clinic Limited | Other services | 2021 |
| MGS Catering Ltd | Hospitality | 2014 |
| MH Energy LLP | | 2011 |