| Meta Living Limited | Construction | 2021 |
| Metahack Ltd | Professional & scientific | 2026 |
| Metal & Modular Fabrication Services Ltd | Manufacturing | 2014 |
| Metal Supermarkets Franchising UK Limited | Professional & scientific | 2011 |
| Metal Supermarkets UK Limited | Wholesale & retail | 1996 |
| Metalfacture Limited | Manufacturing | 1997 |
| Metalite Limited | Manufacturing | 1990 |
| Metallic Yellow Ltd | Wholesale & retail | 2023 |
| Metaltek Engineering Solutions Limited | Construction | 2011 |
| Metaverse Designs Limited | Extraterritorial | 2012 |
| Metcalf Advisory Solutions Ltd | Professional & scientific | 2020 |
| Metcalf Engineering Ltd | Professional & scientific | 2020 |
| Metcalf Multisports Limited | Arts & recreation | 2014 |
| Metcalf Properties Ltd | Real estate | 2024 |
| Meteor 360 Limited | Professional & scientific | 2023 |
| Meterbolic Health Ltd | Health & social care | 2025 |
| Methersgate Speciality Ltd | Transport & logistics | 2014 |
| Methley Opportunities Ltd | Construction | 2014 |
| Method Investment Limited | Real estate | 2023 |
| Meticulous Limited | Other services | 2003 |
| Metric Design & Build Limited | Construction | 2021 |
| Metric International Ltd | Wholesale & retail | 2020 |
| Metric Pixel Limited | Wholesale & retail | 2025 |
| Metricize Technologies Ltd | Information & communication | 2017 |
| Metrix XP Limited | Arts & recreation | 2025 |
| Metro Development Group Limited | Real estate | 2025 |
| Metro Digital Limited | Professional & scientific | 2008 |
| Metro Environment Ltd | Professional & scientific | 2008 |
| Metro Inspection Services Limited | Administrative & support | 1997 |
| Metro Leicester Ltd | Real estate | 2026 |
| Metro Lodge Hotels Ltd | Hospitality | 2012 |
| Metro Safety Group Limited | Financial services | 2014 |
| Metro Safety Limited | Professional & scientific | 2004 |
| Metro SRM LLP | | 2011 |
| Metro-Boulot-Dodo Limited | Arts & recreation | 2003 |
| Metrocapital Securities Limited | Construction | 2012 |
| Metron Capital Ltd | Real estate | 2023 |
| Metropol Granite Marble Limited | Wholesale & retail | 2020 |
| Metropole Ventures LP | | 2017 |
| Metropolis Residential Limited | Real estate | 2018 |
| Metsort Limited | Real estate | 1990 |
| Mettex Fasteners Limited | Wholesale & retail | 1989 |
| Mettler-Toledo Limited | Manufacturing | 1969 |
| Mettleshop Limited | Manufacturing | 1996 |
| Meviora Measurment Technologies Ltd | Manufacturing | 2025 |
| Mewar Fuels Ltd | Wholesale & retail | 2025 |
| Mewar Group Ltd | Financial services | 2023 |
| Mewar Healthcare Ltd | Health & social care | 2025 |
| Mewline Ltd | Wholesale & retail | 2021 |
| Mewly Shop Limited | Wholesale & retail | 2025 |
| Mews Management Company (Oadby) Limited | Households | 1995 |
| Mexl Express Limited | Transport & logistics | 2007 |
| Mexpi Limited | Wholesale & retail | 2012 |
| Meyer Lansky Investments Limited | Real estate | 2015 |
| Meyrick Psychology Services Ltd | Education | 2022 |
| Meza Optical Services Ltd | Health & social care | 2025 |
| Mezyan Ltd | Wholesale & retail | 2024 |
| MEZZ9.COM Limited | Construction | 2010 |
| Mezzanine Ltd | Professional & scientific | 2015 |
| MF Associates (Education) Ltd | Education | 2014 |
| MF Brand Holdings Ltd | Extraterritorial | 2011 |
| MF Consulting Services Limited | Professional & scientific | 2024 |
| MF Living Ltd | Real estate | 2025 |
| MF Optics Ltd | Health & social care | 2019 |
| MF Wholesalers Ltd | Wholesale & retail | 2025 |
| MF& M Enterprises Limited | Real estate | 2025 |
| MFA Property Holdings Ltd | Real estate | 2025 |
| Mfam (Leicester) Limited | Real estate | 2019 |
| MFB Investments Ltd | Financial services | 2022 |
| MFH Supply Ltd | Wholesale & retail | 2026 |
| MFI Consultancy Limited | Professional & scientific | 2020 |
| Mfip Ltd | Wholesale & retail | 2024 |
| Mfjretrog Limited | Wholesale & retail | 2022 |
| MFK Food Trading Ltd | Wholesale & retail | 2023 |
| MFL Legal Limited | Professional & scientific | 2016 |
| Mflight Ltd | Transport & logistics | 2022 |
| MFN Healthcare Ltd | Health & social care | 2016 |
| MFP Leicester Ltd | Real estate | 2024 |
| Mfp-Enterprises Ltd | Wholesale & retail | 2016 |
| MFS Funeral Services Ltd | Other services | 2021 |
| MFT Care Ltd | Health & social care | 2015 |
| MG Clothing Ltd | Wholesale & retail | 2026 |
| MG Convenience Ltd | Wholesale & retail | 2026 |
| MG Driver Hire Ltd | Administrative & support | 2019 |
| MG Logistics Ltd | Financial services | 2015 |
| MG Magna Wholesale and Retail Limited | Wholesale & retail | 2024 |
| MG Tech Consulting Ltd | Information & communication | 2020 |
| MG Trade London Limited | Professional & scientific | 2024 |
| MG XO Limited | Real estate | 2020 |
| MG13 Investments Ltd | Real estate | 2025 |
| Mgar (Roofing) Limited | Construction | 2013 |
| MGB Medical Ltd | Health & social care | 2023 |
| MGB Restaurants Ltd | Hospitality | 2002 |
| MGM Retail Limited | Wholesale & retail | 2019 |
| MGN Catering Ltd | Hospitality | 2026 |
| MGR Fire Safety Consultants Limited | Professional & scientific | 2018 |
| MGR Property Ltd | Real estate | 2025 |
| MGS Haulage Ltd | Transport & logistics | 2026 |
| MGW Commercial Property Maintenance Limited | Construction | 2017 |
| Mgworld Ltd | Wholesale & retail | 2025 |