| Madeline Direct LP | | 2014 |
| Mademoiselle Macaron Limited | Manufacturing | 2014 |
| Madera Traders SLP | | 2005 |
| Madero Group LP | | 2016 |
| Madethis Ltd | Information & communication | 2023 |
| Madetocare Ltd | Health & social care | 2013 |
| MADHATTER8 Ltd | Hospitality | 2019 |
| Madhav Convenience Store Ltd | Wholesale & retail | 2024 |
| Madin Consulting LP | | 2016 |
| Madina Steel LP | | 2017 |
| Madire SP | | 2004 |
| Madison & Co. L.P. | | 2012 |
| Madison Commerce LP | | 2014 |
| Madison Pristine LP | | 2016 |
| Madison Union LP | | 2014 |
| Madlab Limited | Education | 1994 |
| Madogs Limited | Real estate | 1982 |
| Madras Dosa House Ltd | Hospitality | 2010 |
| Madre DE Dios LP | | 2000 |
| Madrigalia LP | | 2000 |
| Madro Group LP | | 2015 |
| MAE Chesser Ltd | Hospitality | 2025 |
| MAE Macpherson Art Studio Limited | Wholesale & retail | 2025 |
| Maeli Mini Market (Edinburgh) Ltd | Wholesale & retail | 2026 |
| Maestro Corporation LP | | 2016 |
| Mafalda LP | | 2012 |
| Mafalda Wolf Grant Limited | Other services | 2024 |
| Mafelco Limited | Transport & logistics | 2013 |
| Mafli Ltd | Wholesale & retail | 2025 |
| Mag.Earth Ltd | Information & communication | 2026 |
| MAG2025 Ltd | Wholesale & retail | 2025 |
| Magaz LP | | 2014 |
| Magda KAY LP | | 2021 |
| Magdalena Muller Nail Academy UK Ltd | Education | 2020 |
| Magdalena Szczepaniak Ltd | Transport & logistics | 2026 |
| Magdalene Technologies Ltd | Professional & scientific | 2013 |
| Magella LP | | 2015 |
| Magenta HR Consulting Limited | Professional & scientific | 2010 |
| Magenta Trading LP | | 2018 |
| Magentum Logistics Europe Limited | Wholesale & retail | 2023 |
| Magestile Consulting Limited | Information & communication | 2010 |
| Maggielux Ltd | Wholesale & retail | 2018 |
| Maggy HR Solutions LP | | 2024 |
| Magic & Beyond LP | | 2025 |
| Magic Alliance LP | | 2016 |
| Magic Astrielle LP | | 2025 |
| Magic Aurora LP | | 2015 |
| Magic Business Development LP | | 2016 |
| Magic Corporation L.P. | | 2012 |
| Magic Crystal LP | | 2016 |
| Magic Loom Ltd | Information & communication | 2025 |
| Magic of Unicorn Limited | Manufacturing | 2024 |
| Magic Potion PVT Ltd | Wholesale & retail | 2026 |
| Magic Rental LP | | 2016 |
| Magical Day LP | | 2016 |
| Magical Edinburgh Ltd | Administrative & support | 2026 |
| Magik Cavern Ltd | Wholesale & retail | 2023 |
| Maglex Partners LP | | 2016 |
| Magma Geological Limited | Mining & quarrying | 2018 |
| Magna Trading Project LP | | 2016 |
| Magna World Travel Limited | Administrative & support | 2026 |
| Magnam Trade LP | | 2015 |
| Magnapark Properties Limited | Real estate | 1989 |
| Magnat Company LP | | 2016 |
| Magnat Investments L.P. | | 2009 |
| Magnat Services LP | | 2016 |
| Magnesium Capital I Carry LP | | 2021 |
| Magnesium Capital I GP (Scotland) LLP | | 2021 |
| Magnesium Capital I Pumpkin Co-Invest LP | | 2023 |
| Magnet Project LP | | 2016 |
| Magnetic and Manifest LP | | 2022 |
| Magnetic Glazing LP | | 2015 |
| Magnetic Horse LP | | 2016 |
| Magnetic Nails GB Ltd | Wholesale & retail | 2021 |
| Magnetic North Theatre Productions Limited | Arts & recreation | 1999 |
| Magnetosphere Ltd | Professional & scientific | 2020 |
| Magni (Analitical &) Consulting L.P. | | 2014 |
| Magnifico Trading L.P. | | 2021 |
| Magno SP | | 2001 |
| Magnohard Investments Holdings LP | | 2019 |
| Magnolia Alliance LP | | 2015 |
| Magnolia Solutions Ltd | Professional & scientific | 2010 |
| Magnolia Towers SP | | 2004 |
| Magnolia Trade LP | | 2016 |
| Magnora Offshore Wind Holding Limited | Energy | 2021 |
| Magnora UK PV Holding Limited | Financial services | 2022 |
| Magnum Capital, L.P. | | 2006 |
| Magnum Impex LP | | 2012 |
| Magnus Klein Limited | Information & communication | 2020 |
| Magnus Trade LP | | 2018 |
| Magoda Nordic LLP | | 2012 |
| Magoo (Scot) Ltd. | Construction | 2017 |
| Magpie Books CIC | Wholesale & retail | 2025 |
| Magrit Trading LP | | 2014 |
| Maguire and Partners Limited | Professional & scientific | 2013 |
| Mah-Sah-Tech Ltd. | Wholesale & retail | 2022 |
| Mahadev Foods Ltd | Wholesale & retail | 2026 |
| Maheshwari Properties Ltd | Real estate | 2018 |
| Mahi Group Limited | Hospitality | 2021 |
| Mahi Limited | Professional & scientific | 2025 |