| Megal Software Limited | Information & communication | 2026 |
| Megan Louise Beauty Limited | Other services | 2023 |
| Megbay Limited | Transport & logistics | 2021 |
| Megsoph Limited | Professional & scientific | 2025 |
| Mehmet AGA Properties Ltd | Real estate | 2025 |
| Meicy Shea Beauty Ltd | Wholesale & retail | 2025 |
| Meir 2020 Vision CIC | Health & social care | 2023 |
| Meir Consultancy Limited | Information & communication | 2017 |
| Meir Glass Centre Limited | Construction | 1983 |
| Meir Management Limited | Wholesale & retail | 2023 |
| Meir Matters CIC | Other services | 2023 |
| Meir Park Electrical Ltd | Energy | 2016 |
| Meir Pizza and Grill Limited | Hospitality | 2025 |
| Meir Pizza Limited | Hospitality | 2021 |
| Meir Sandon Limited | Hospitality | 2020 |
| Meir Takeaway Limited | Hospitality | 2025 |
| Meliora Renovations Ltd | Construction | 2024 |
| Melisa One Limited | Wholesale & retail | 2015 |
| Melleon Ltd | Hospitality | 2025 |
| Mellor & Mottram Limited | Construction | 2017 |
| Mellor & Mottram Mechanical Services Limited | Construction | 2003 |
| Melody Ventures Ltd | Wholesale & retail | 2024 |
| Melvern Property Services Ltd | Construction | 2026 |
| Mel’S Cakes and Bakes Ltd | Manufacturing | 2024 |
| Membsys Ltd | Professional & scientific | 2025 |
| Memento Group Holdings Limited | Financial services | 2024 |
| Memo Paris (UK) Ltd | Wholesale & retail | 2012 |
| MEN Rebuilding MEN CIC | Health & social care | 2026 |
| Mena UK Legal Consultancy Ltd | Professional & scientific | 2025 |
| Menjim Limited | Wholesale & retail | 2024 |
| Menzies Asset Management Ltd | Other services | 2012 |
| Meraki Greek Street Food Ltd | Hospitality | 2024 |
| Mercia International Limited | Arts & recreation | 2018 |
| Mercian GP Network Limited | Other services | 2018 |
| Mercy & Clara Healthcare Ltd | Health & social care | 2019 |
| Mere END Consultants Limited | Construction | 2010 |
| Merelake Engineering Services Ltd | Professional & scientific | 2024 |
| Meriway 2000 Limited | Professional & scientific | 1998 |
| Merley Sonic Ltd | Hospitality | 2025 |
| Messingham Tandoori Ltd | Hospitality | 2021 |
| Meta GAS Ltd | Construction | 2022 |
| Meta Style Limited | Wholesale & retail | 2024 |
| Metal Proving Services Limited | Professional & scientific | 2013 |
| Metal Stairs Limited | Construction | 2018 |
| Metamix Holdings Ltd | Financial services | 2019 |
| Metro Ethnic Foods Limited | Wholesale & retail | 2025 |
| Metstar Ltd | Wholesale & retail | 2025 |
| Metsys Limited | Information & communication | 2023 |
| Mevida Ltd | Education | 2023 |
| Mexo Ltd | Wholesale & retail | 2020 |
| Meyer Timber Limited | Wholesale & retail | 1998 |
| Mezzanine Floors Direct Ltd | Construction | 2023 |
| MF Distributions Ltd | Wholesale & retail | 2025 |
| MFN Crest Limited | Wholesale & retail | 2026 |
| MFS1985 Ltd | Wholesale & retail | 2024 |
| MG and Daughters Logistic Ltd | Transport & logistics | 2019 |
| MG Medical Services Limited | Health & social care | 2021 |
| MG Rover Mobile Mechanics Limited | Wholesale & retail | 2021 |
| MG88 Transport Ltd | Transport & logistics | 2024 |
| MGB Engineering & Skip Manufacturers Limited | Manufacturing | 2019 |
| MGH70 Ltd | Professional & scientific | 2025 |
| MGK PVT Ltd | Health & social care | 2019 |
| MGP Investments Ltd | Real estate | 2025 |
| MH Group Midlands Ltd | Wholesale & retail | 2023 |
| MH Hotel & Spa Operations Limited | Hospitality | 2024 |
| MH Property Developments (S-O-T) Limited | Construction | 2014 |
| MH Web Solutions Limited | Information & communication | 2023 |
| MHD Global Services Ltd | Administrative & support | 2025 |
| MHF Locum Ltd | Professional & scientific | 2020 |
| MHL Property Ltd | Real estate | 2024 |
| MHM Property Ventures Ltd | Real estate | 2024 |
| Mhofu Fresh Foods Limited | Wholesale & retail | 2025 |
| MHS Care Limited | Public administration | 2022 |
| Mhways Ltd | Wholesale & retail | 2025 |
| MI Amor Stoke Ltd | Hospitality | 2024 |
| MI Fashion & Beauty Ltd | Wholesale & retail | 2024 |
| MI Mammi's CIC | Hospitality | 2025 |
| MI Stocks Ltd | Wholesale & retail | 2025 |
| MI Taxaccs Ltd | Extraterritorial | 2022 |
| Mian Mudasar Y Limited | Wholesale & retail | 2025 |
| Miansomo Investments Limited | Financial services | 2021 |
| Miansomo Limited | Financial services | 2018 |
| Miansomo Property Services Limited | Real estate | 2021 |
| Miart Technology Limited | Information & communication | 1998 |
| Mich Truck Ltd | Transport & logistics | 2020 |
| Michael G COX & Associates Limited | Professional & scientific | 2017 |
| Michael Johnson IFA Limited | Administrative & support | 2017 |
| Michael Salt Ltd | Professional & scientific | 2018 |
| Michaelmas Ltd | Other services | 2020 |
| Michelin Tyre Public Limited Company | Manufacturing | 1905 |
| Michrab Private Limited | Health & social care | 2015 |
| Micii Limited | Hospitality | 2025 |
| Mick Reilly Limited | Hospitality | 2024 |
| Mick Walsh GAS Ltd | Construction | 2022 |
| Micmic Ltd | Health & social care | 2025 |
| Microvend Limited | Wholesale & retail | 2019 |
| MID Staffordshire Postgraduate Medical Centre (Education) | Education | 1994 |
| Midas DIM Ltd | Construction | 2019 |
| Middleport Matters Community Trust | Health & social care | 2018 |
| Middleton J Ltd | Construction | 2022 |