| Mufulira Limited | Health & social care | 1981 |
| Mughal Doyan UK Limited | Wholesale & retail | 2025 |
| Mughal's Mart Ltd | Wholesale & retail | 2025 |
| Mugsupply Ltd | Manufacturing | 2019 |
| Muhammad Adil Ltd | Wholesale & retail | 2025 |
| Muhammad Afzal Ltd | Wholesale & retail | 2026 |
| Muhammad Genghis Mugal Limited | Manufacturing | 2019 |
| Muhammad Qasim Ltd | Wholesale & retail | 2025 |
| Muhammad Ramzan Ltd | Wholesale & retail | 2025 |
| Muhammad Razaq Khan Ltd | Wholesale & retail | 2025 |
| Muhammad Shehzad Ltd | Wholesale & retail | 2026 |
| Muhammed Umer Ltd | Wholesale & retail | 2025 |
| Muhasib Ltd | Professional & scientific | 2020 |
| Muhtaseb Medical Ltd | Information & communication | 2018 |
| Muhua Import & Export Co., Limited | Wholesale & retail | 2021 |
| Mukerji Holdings Limited | Real estate | 2021 |
| Mukerji Properties Limited | Real estate | 2026 |
| Mukyen Investments UK Ltd | Financial services | 2025 |
| Mukzzland Global Limited | Wholesale & retail | 2019 |
| Mulaqati Ltd | Wholesale & retail | 2025 |
| Mular Limited | Wholesale & retail | 2020 |
| Mulberry Capital Management Ltd | Professional & scientific | 2015 |
| Mulberry Clinic Limited | Health & social care | 2024 |
| Mulberry Living Ltd | Real estate | 2025 |
| Mulberry Wealth Client Services Limited | Financial services | 2001 |
| Mulberry Wealth Management Limited | Financial services | 2009 |
| Mulberry Wealth Management NO2 Limited | Financial services | 2013 |
| Muler Windows Ltd | Wholesale & retail | 2016 |
| Muli-Trans Ltd | Transport & logistics | 2018 |
| Mullaghcarton Ltd | Administrative & support | 2015 |
| Mullans Supplies Limited | Wholesale & retail | 2020 |
| Multani Services Ltd | Real estate | 2025 |
| Multi Car Directs Ltd | Professional & scientific | 2019 |
| Multi Fit Renovations Ltd | Construction | 2021 |
| Multi Healthcare Solutions Limited | Health & social care | 2019 |
| Multi League Co., Ltd | Extraterritorial | 2019 |
| Multi Print Services Limited | Extraterritorial | 2008 |
| Multiaim Limited | Real estate | 1997 |
| Multichoice 2 UK Ltd | Health & social care | 2019 |
| Multiform Property Development Co. Limited | Real estate | 1989 |
| Multifuel Warehouse Ltd | Wholesale & retail | 2015 |
| Multiitex Ltd | Construction | 2023 |
| Multimash Ltd | Administrative & support | 2025 |
| Multimedia Marketing Services Ltd | Professional & scientific | 2018 |
| Multiple Benefits Resources Ltd | Wholesale & retail | 2023 |
| Multiple Retail Limited | Real estate | 2025 |
| Multiplii Limited | Information & communication | 2018 |
| Multiservice Building Solution Ltd | Construction | 2018 |
| Multisite Recruitment Services Limited | Professional & scientific | 2011 |
| Multiverse Computing Ltd | Information & communication | 2023 |
| Multiwin Group Co., Ltd | Financial services | 2021 |
| Mulumba and Partners Ltd | Administrative & support | 2024 |
| Mum's Carer Limited | Health & social care | 2019 |
| Mumbai Yorkshire Ltd | Hospitality | 2017 |
| Mumbli Ltd | Health & social care | 2018 |
| Mumet Ltd | Wholesale & retail | 2025 |
| Mummy ME Shop Limited | Wholesale & retail | 2025 |
| Mums (Sussex) Ltd | Wholesale & retail | 2013 |
| Mums Daily PVT Ltd | Hospitality | 2024 |
| Mums Kitchen Cookbook Limited | Information & communication | 2025 |
| Mumshape Europe Limited | Information & communication | 2018 |
| Munawor Group Ltd | Wholesale & retail | 2026 |
| Munchdrop Ltd | Hospitality | 2019 |
| Munday Developments Limited | Real estate | 2022 |
| Mundee Ltd | Wholesale & retail | 2024 |
| Mundo Freelance Limited | Manufacturing | 2014 |
| Mundon Trading Ltd | Professional & scientific | 2017 |
| Mundus Limited | Administrative & support | 2025 |
| Munio Developments Limited | Real estate | 2020 |
| Munir Brothers Limited | Real estate | 2014 |
| Munnelly Plant Hire Limited | Administrative & support | 2013 |
| Munso Limited | Information & communication | 2025 |
| Munster Ground Work Construction Ltd | Construction | 2016 |
| Munsterberg Group GmbH & Co., Ltd | Extraterritorial | 2023 |
| Muntontime Limited | | 1961 |
| Munz Ltd | Construction | 2018 |
| Mura Properties Limited | Real estate | 2026 |
| Murder Mystery Events Limited | Arts & recreation | 2003 |
| Murdoch Distribution Limited | Wholesale & retail | 2022 |
| Murendo Ltd | Wholesale & retail | 2025 |
| Muretex Limited | Professional & scientific | 2003 |
| Murfet Station Road Ltd | Construction | 2019 |
| Murielle Healing Ltd | Health & social care | 2025 |
| Murley Assets Ltd | Real estate | 2019 |
| Murley Media Ltd | Information & communication | 2019 |
| Murlink Solutions Ltd | Information & communication | 2017 |
| Murodiljon Ltd | Other services | 2025 |
| Murray Medical Limited | Wholesale & retail | 2010 |
| Murray Partners PC | | 2017 |
| Murtafaat Deem Al-Shamikhah for Commercial Business Ltd | Wholesale & retail | 2024 |
| Musakhail DRY Fruits Ltd | Wholesale & retail | 2025 |
| Musamad Trading (U.K) Limited | Construction | 2011 |
| Musaratjabeen Trading Limited | Wholesale & retail | 2025 |
| Muscle Craft Ltd | Wholesale & retail | 2026 |
| Muscle MAD Ltd | Wholesale & retail | 2021 |
| Muse BMS Limited | Administrative & support | 2020 |
| Muse Solutions Ltd | Professional & scientific | 2021 |
| Musecolo Ltd | Wholesale & retail | 2021 |
| Museum Quarter Ltd | Construction | 2019 |
| Museum View Residents Ltd | Households | 2024 |