| MAX Johnson Ltd | Wholesale & retail | 2023 |
| MB Housing Services Ltd | Real estate | 2024 |
| MB Property Lets Ltd | Real estate | 2015 |
| MC Residantial Properties Ltd | Real estate | 2025 |
| MDA Electrical Contractors Ltd | Construction | 2025 |
| MDA Property Holdings Ltd | Real estate | 2026 |
| MDH Corporation Ltd | Real estate | 2025 |
| Meat in Place Limited | Wholesale & retail | 2003 |
| MED Care International Group Ltd | Manufacturing | 2025 |
| Medax Construction Limited | Construction | 2025 |
| Medici Capital Holdings Ltd | Wholesale & retail | 2022 |
| Medici Enterprise Ltd | Information & communication | 2014 |
| Medidenta Limited | Health & social care | 2015 |
| Medlas Limited | Manufacturing | 2017 |
| Medua Cares Limited | Real estate | 2025 |
| Meethaq United Global Business Ltd | Wholesale & retail | 2025 |
| Mehdav Property Ltd | Real estate | 2024 |
| Memunatu Ltd | Wholesale & retail | 2021 |
| Memz Catering Limited | Hospitality | 2023 |
| Meno Community Outreach CIC | Health & social care | 2025 |
| Mental Health HQ CIC | Information & communication | 2022 |
| Mental Health Nexus Ltd | Health & social care | 2026 |
| MET Apartments (LEE) Freehold Limited | Households | 2008 |
| Metusa Property Ltd | Real estate | 2024 |
| Mewana Limited | Real estate | 2018 |
| MEZ Property Ltd | Real estate | 2022 |
| MG Mechanical Force Ltd | Construction | 2024 |
| MGA Investment Group Ltd | Real estate | 2024 |
| MGE Pathology Limited | Health & social care | 2025 |
| MGR Estates Ltd | Real estate | 2019 |
| Mherl Relocations Ltd | Transport & logistics | 2025 |
| MHO Contracting Services Ltd | Construction | 2024 |
| MHP Elec-Plumb Limited | Wholesale & retail | 2018 |
| Mhpn Property Ltd | Real estate | 2023 |
| MHS Retail Ltd | Wholesale & retail | 2025 |
| MI Building Contractors Ltd | Construction | 2015 |
| MI Building Projects Ltd | Construction | 2026 |
| Miagi Management Ltd | Real estate | 2024 |
| Micaa International Ltd | Wholesale & retail | 2024 |
| Micobi Limited | Wholesale & retail | 2013 |
| Micron Travels and Tours Limited | Administrative & support | 2024 |
| Mighty Cleaning Services Ltd | Administrative & support | 2020 |
| Mihir Constructions Limited | Construction | 2025 |
| Milan & Alim Services Ltd | Wholesale & retail | 2021 |
| Milan Real Estate Limited | Real estate | 2020 |
| Milania Property Ltd | Real estate | 2021 |
| Millers Bootsale Ltd | Administrative & support | 2022 |
| Mimico 2014 Ltd | Administrative & support | 2014 |
| Mindong Construction Ltd | Construction | 2011 |
| Ministryflow Limited | Arts & recreation | 2025 |
| Minority Ltd | Professional & scientific | 2016 |
| MIR & Sons Ltd | Real estate | 2024 |
| MIR Installation Ltd | Construction | 2025 |
| Mirror Mirror (Bexleyheath) Limited | Other services | 2024 |
| Mirudi Barbers Ltd | Other services | 2024 |
| Mission Health UK Limited | Health & social care | 2010 |
| Misters Hair Solutions Ltd | Other services | 2025 |
| MIT Beauty Ltd | Other services | 2024 |
| Mitul Ltd | Real estate | 2020 |
| MIX Trade Ltd | Other services | 2017 |
| MJ & ML Property Ltd | Real estate | 2024 |
| MMB Accounting and Bookkeeping Ltd | Professional & scientific | 2016 |
| Mmsaen Limited | Construction | 2019 |
| MNM Trans Limited | Transport & logistics | 2022 |
| MO FIX Services Ltd | Construction | 2025 |
| Moat Croft Management Company Limited | Real estate | 2020 |
| Modest Homes Limited | Real estate | 2020 |
| Moeazusa Ltd | Information & communication | 2023 |
| Moflipsco Ltd | Wholesale & retail | 2025 |
| Mohanagar Ltd | Hospitality | 2016 |
| Monik Drinks Wholesale Ltd | Wholesale & retail | 2025 |
| Monster Emporium Ltd | Education | 2020 |
| Montrose Builders Ltd | Construction | 2016 |
| Montrose Property Services Ltd | Real estate | 2022 |
| Moocloud Ltd | Information & communication | 2014 |
| Moonlight Property Ltd | Real estate | 2019 |
| Morgan Alexis Limited | Professional & scientific | 2020 |
| Morgan Heating & Plumbing Ltd | Construction | 2012 |
| Morleys Welling Ltd | Hospitality | 2024 |
| Morryjoy Prime Group Ltd | Wholesale & retail | 2026 |
| Mortech Solutions Ltd | Professional & scientific | 2022 |
| Mosaic Collective Limited | Manufacturing | 2019 |
| Moss Rose Wellness Ltd | Other services | 2026 |
| Moto-Pass Motorcycle Training Limited | Other services | 2014 |
| Movalta Ltd | Transport & logistics | 2025 |
| MOZ 50 Flavours Ltd | Hospitality | 2018 |
| Mpaach Keik Dezignz Ltd | Manufacturing | 2018 |
| MR & MRS Suba Ltd | Wholesale & retail | 2025 |
| MR Builders Ltd | Construction | 2025 |
| MR Logic Ltd | Information & communication | 2025 |
| MR Mobile Fitter Ltd | Wholesale & retail | 2023 |
| MRJ Logistics Ltd | Transport & logistics | 2017 |
| MSA Supplies Ltd | Wholesale & retail | 2024 |
| Mshary’ Shrq Mjan Ltd | Wholesale & retail | 2025 |
| MSJ Home Services Ltd | Construction | 2021 |
| Mssw Consultants Ltd | Health & social care | 2014 |
| MST Traders Ltd | Wholesale & retail | 2025 |
| MSV Ventures Limited | Wholesale & retail | 2023 |
| Multitop Accountants Ltd | Professional & scientific | 2018 |
| Munyabeans Limited | Administrative & support | 2024 |