| Mian Hassam Cons Ltd | Construction | 2024 |
| Mian Junction Ltd | Construction | 2025 |
| Mian Sahil Ltd | Wholesale & retail | 2026 |
| Mian Traders 786 Ltd | Wholesale & retail | 2023 |
| Mianbrothertraders Ltd | Wholesale & retail | 2024 |
| Miaprime Builders Ltd | Manufacturing | 2024 |
| Miauzdirect Ltd | Wholesale & retail | 2026 |
| Mia’S Imports Ltd | Wholesale & retail | 2026 |
| Michael Ogunleye Security Ltd | Administrative & support | 2024 |
| Michael Yaoxia Ltd | Wholesale & retail | 2025 |
| Michan Property Group Ltd | Real estate | 2022 |
| Michan Property LLP | | 2022 |
| Michmark Painting Limited | Construction | 2002 |
| Mickey's Transport Ltd | Transport & logistics | 2023 |
| Miclaus Construct Limited | Construction | 2015 |
| Micro Minti Ltd | Wholesale & retail | 2026 |
| Microcomputation Software Limited | Information & communication | 1983 |
| Micron Technology Ltd | Information & communication | 2017 |
| Microncrete Limited | Construction | 2025 |
| Microsolaris Ltd | Information & communication | 2021 |
| Mideyclothings Ltd | Manufacturing | 2026 |
| Midlands Medical Solutions Ltd | Health & social care | 2018 |
| Midnight Realms Ltd | Information & communication | 2021 |
| Midway Group Ltd | Wholesale & retail | 2020 |
| Mighty Global Trading Limited | Construction | 2026 |
| Migration and Risks Ltd | Education | 2025 |
| Migss Tiles & Luxury Interiors Ltd | Wholesale & retail | 2025 |
| Mihai the Builder Ltd | Construction | 2019 |
| Mihail-Alin Gargaun Ltd | Wholesale & retail | 2026 |
| Mihaitatraders Limited | Wholesale & retail | 2020 |
| Mihra Ltd | Hospitality | 2026 |
| MII Box Limited | Hospitality | 2026 |
| Miisol Ltd | Information & communication | 2015 |
| Mijd Limited | Information & communication | 2011 |
| MIK Prime Estates Ltd | Real estate | 2018 |
| Mikael Omar Limited | Health & social care | 2023 |
| Mikail Ltd | Wholesale & retail | 2014 |
| Mike EBB Development Ltd | Real estate | 2020 |
| Mike Horizon Roofing Limited | Construction | 2011 |
| Mike Nike Logistics Ltd | Transport & logistics | 2017 |
| Mikeyjdotnet Limited | Arts & recreation | 2021 |
| Mikz & Milly Limited | Wholesale & retail | 2015 |
| MIL Studio Ltd | Construction | 2023 |
| Milano Eyewear Ltd | Wholesale & retail | 2021 |
| Milasius UK Ltd Limited | Wholesale & retail | 2017 |
| Mileexec Limited | Transport & logistics | 2026 |
| Milena Baby Studio Limited | Wholesale & retail | 2025 |
| Miles Impex Limited | Wholesale & retail | 2021 |
| Miles N C Crispin Ltd | Information & communication | 2026 |
| Miles Records Ltd | Information & communication | 2019 |
| Milestone Mosaic Limited | Construction | 2020 |
| Milestone Travel Ltd | Administrative & support | 2013 |
| Milestone Used Motors Ltd | Wholesale & retail | 2025 |
| Milicah Limited | Health & social care | 2018 |
| Milkies Deli and Desserts Ltd | Hospitality | 2021 |
| Mill and Co PIF Ltd | Real estate | 2022 |
| Mill Borough Investments Ltd | Real estate | 2025 |
| Mill Lane Chadwell Ltd | Real estate | 2018 |
| Mill Lane Riding School Ltd | Other services | 2013 |
| Mill Lane Woodford Ltd | Real estate | 1988 |
| Mill&Co Ltd | Real estate | 2021 |
| Milla Zaid Limited | Administrative & support | 2023 |
| Millenium Village Management Company Limited | Households | 1997 |
| Millennial Media Ltd | Professional & scientific | 2020 |
| Millennium Cash & Carry Limited | Wholesale & retail | 1999 |
| Millennium Direct Delivery Limited | Extraterritorial | 2010 |
| Millennium Group (UK) Limited | Extraterritorial | 2010 |
| Millennium Wholesale Limited | Extraterritorial | 2010 |
| Miller C Group Ltd | Hospitality | 2007 |
| Millet Maduva Ltd | Hospitality | 2025 |
| Millfield Fairview Limited | Other services | 2023 |
| Millionaire Club Limited | Wholesale & retail | 2024 |
| Milly Styles Limited | Wholesale & retail | 2020 |
| Milton Accountants Ltd | Professional & scientific | 2020 |
| Milton Albion Limited | Information & communication | 2023 |
| Milton Mill Limited | Real estate | 1995 |
| Mily Management 4U Ltd | Real estate | 2025 |
| Mimbar International Ltd | Professional & scientific | 2022 |
| Mimi D Ltd | Public administration | 2023 |
| Mimiroha Limited | Health & social care | 2025 |
| Mimosa Care Services Limited | Administrative & support | 2018 |
| MIN Investment UK Ltd | Real estate | 2019 |
| Mina Finance Limited | Real estate | 2004 |
| Minahil Ltd | Hospitality | 2018 |
| Minamedia Ltd | Professional & scientific | 2025 |
| Mind Drawer Limited | Information & communication | 2012 |
| Mind Matters Care & Support Ltd | Health & social care | 2024 |
| Mind.Drop Ltd | Wholesale & retail | 2014 |
| Mindbench Consulting Ltd | Administrative & support | 2008 |
| Mindgrid Limited | Professional & scientific | 2024 |
| Mindhub Services Ltd | Health & social care | 2023 |
| Mindi Builders Limited | Construction | 2014 |
| Mindrise Academy Ltd | Education | 2025 |
| Mindsara Ltd | Information & communication | 2022 |
| Mindset Solutions and Consultancy Ltd | Professional & scientific | 2024 |
| Mindsetting Limited | Health & social care | 2021 |
| Mindshift Ventures Ltd | Information & communication | 2026 |
| Minerva DFM Support Services Limited | Professional & scientific | 2018 |
| Minerva Management Consulting Limited | Professional & scientific | 2014 |
| Minerva Marketing and Distribution Services Limited | Wholesale & retail | 2017 |