| Metatron Investments Ltd | Construction | 2015 |
| Metcorp Ltd | Wholesale & retail | 2019 |
| Meter Express Limited | Construction | 2019 |
| Metering & Measurement Services Limited | Information & communication | 2012 |
| Meterna Maternity Ltd | Health & social care | 2026 |
| Metlab Technologies Limited | Manufacturing | 2012 |
| Metlabmachine & Supplies Ltd | Manufacturing | 2025 |
| Metricsilo Limited | Professional & scientific | 2021 |
| Metro 7 Kitchen Ltd | Hospitality | 2026 |
| Metro Bazaar Limited | Wholesale & retail | 2025 |
| Metro Builders Limited | Construction | 2015 |
| Metro Glide Limited | Transport & logistics | 2026 |
| Metro Income LP | | 2016 |
| Metro Mini Mart Limited | Wholesale & retail | 2023 |
| Metro Pharmacy Limited | Wholesale & retail | 1994 |
| Metro Tax Solutions Ltd | Professional & scientific | 2016 |
| Metrodog Limited | Information & communication | 2000 |
| Metroguard Group Ltd | Financial services | 2020 |
| Metroguard Limited | Administrative & support | 2017 |
| Metroguard Oxford Limited | Administrative & support | 2004 |
| Metroguard Training Academy Limited | Education | 2026 |
| Metrolord Limited | Transport & logistics | 2004 |
| Metronet IT & Cloud Solutions Ltd | Wholesale & retail | 2026 |
| Metropolitan Accountants Limited | Professional & scientific | 2009 |
| Metta Accountants Limited | Professional & scientific | 2019 |
| Metta Consultancy Ltd | Professional & scientific | 2023 |
| Metwest Limited | Wholesale & retail | 1978 |
| Metwiser Limited | Manufacturing | 2025 |
| Mevlana Spice Ltd | Wholesale & retail | 2020 |
| Mewrs Limited | Health & social care | 2024 |
| Mews Moves Limited | Transport & logistics | 2004 |
| Mexcroft Management Limited | Real estate | 2017 |
| Mexican Flavour Ltd | Hospitality | 2024 |
| Mezza Terra Media Limited | Administrative & support | 2014 |
| Mezzaro Ltd | Wholesale & retail | 2018 |
| MF Contracting Limited | Construction | 2016 |
| MF Interior Projects Ltd | Construction | 2021 |
| MF Laminator Ltd | Other services | 2021 |
| MF6 Co. Ltd | Wholesale & retail | 2022 |
| MFC Jewellery Ltd | Wholesale & retail | 2024 |
| MFM Pharma Limited | Wholesale & retail | 2023 |
| Mfpa Publishing Limited | Manufacturing | 1956 |
| MFS Invest UK Ltd | Real estate | 2022 |
| MG & Co Consulting Ltd | Information & communication | 2022 |
| MG (Mayfair) Ltd | Real estate | 2021 |
| MG Accountants & Tax Advisers Limited | Professional & scientific | 2017 |
| MG ALL Construct Ltd | Construction | 2024 |
| MG Audit Services Ltd | Professional & scientific | 2007 |
| MG Construction Builder Services Ltd | Construction | 2026 |
| MG Contractor Services Ltd | Professional & scientific | 2007 |
| MG Drylining Ltd | Construction | 2023 |
| MG Family Ltd | Construction | 2025 |
| MG Financial Services Ltd | Professional & scientific | 2007 |
| MG Group (Holdings) Ltd. | Financial services | 2006 |
| MG Group (Professional Services) Ltd | Professional & scientific | 2007 |
| MG Group Employment Services Limited | Professional & scientific | 1981 |
| MG Health Limited | Health & social care | 2018 |
| MG Rendering Limited | Construction | 2020 |
| MG Trans Spedition Ltd | Transport & logistics | 2022 |
| MGB Direct Services Limited | Health & social care | 2001 |
| MGH Capital Ltd | Financial services | 2022 |
| Mgld Construct Ltd | Construction | 2017 |
| MGM Catalao Gardens Ltd | Other services | 2024 |
| Mgmt Pro Consulting Limited | Professional & scientific | 2016 |
| MGN Electronics Limited | Manufacturing | 2009 |
| MGP Petrescu Solution Ltd | Construction | 2018 |
| Mgplus Ltd | Manufacturing | 2024 |
| MGR Construction and Subcontractors Ltd | Construction | 2012 |
| MGS Roofing Ltd | Construction | 2022 |
| Mgss Express Ltd | Other services | 2017 |
| MGV Trade Ltd | Wholesale & retail | 2025 |
| MGW Advertising Limited | Information & communication | 2025 |
| MH & GH Properties Limited | Real estate | 2020 |
| MH Custom Properties Ltd | Construction | 2023 |
| MH Healthcare & Cosmetic Ltd | Wholesale & retail | 2025 |
| MH MIR Ltd | Wholesale & retail | 2024 |
| MH Property and Land Group Ltd | Construction | 2021 |
| MHA Rental Ltd | Real estate | 2024 |
| Mhairi-Jane-Pauline Ltd | Real estate | 2018 |
| MHC & MLC OSA (UK) Ltd | Education | 2019 |
| MHC Medical Services Limited | Health & social care | 2012 |
| Mhdinternational Ltd | Professional & scientific | 2018 |
| MHK1 Ltd | Wholesale & retail | 2019 |
| Mhnsp Limited | Construction | 2021 |
| MHS Operations Ltd | Hospitality | 2025 |
| Mhsons Ltd | Wholesale & retail | 2023 |
| Mhysa Ltd | Information & communication | 2022 |
| MI by ME Limited | Wholesale & retail | 2016 |
| MIA Money Ltd | Financial services | 2012 |
| MIA Property Ltd | Real estate | 2018 |
| MIA Yachting Ltd | Transport & logistics | 2023 |
| Miachean Limited | Real estate | 2021 |
| Miada Consulting Ltd | Real estate | 2009 |
| Miada Property Group Ltd | Real estate | 2021 |
| Miami Cars @ UK Ltd | Wholesale & retail | 2025 |
| Miami Weiss Aviation Limited | Professional & scientific | 2020 |
| Mian Shah & Sons Ltd | Professional & scientific | 2025 |
| Miana Ventures Ltd | Real estate | 2021 |
| Mianja Capital Limited | Administrative & support | 2024 |
| Miasharizman Limited | Arts & recreation | 2022 |