| Movein Homes Limited | Real estate | 2024 |
| Moveline Ltd | Other services | 2021 |
| Moverightnow Limited | Real estate | 2007 |
| Movmil Ltd | Construction | 2017 |
| MOX Installations Ltd | Construction | 2024 |
| Moza Food Limited | Hospitality | 2023 |
| MP Assets Ltd | Real estate | 2022 |
| MPB Project Management Limited | Construction | 2005 |
| MPR Property Investors Limited | Real estate | 2024 |
| MR Chips Corporation Limited | Real estate | 2026 |
| MR Joel Ltd | Professional & scientific | 2016 |
| MR Khan Ltd | Hospitality | 2020 |
| MR Rental Properties Limited | Real estate | 2024 |
| MR. Cooper the Science Tutor Ltd | Education | 2025 |
| Mr.Brush Painting&Decorating Ltd | Construction | 2025 |
| MRB Services Limited | Administrative & support | 1983 |
| MRH Construction Services Ltd | Construction | 2020 |
| MRI Holdings Ltd | Administrative & support | 2026 |
| Mrm&A Trade Ltd | Information & communication | 2024 |
| Mroz M Frosbuild Ltd | Construction | 2017 |
| MRP Haulage Limited | Transport & logistics | 2015 |
| Mrrt-Mo Limited | Health & social care | 2023 |
| MRT Bespoke Limited | Manufacturing | 2017 |
| MRT Designs Limited | Manufacturing | 2017 |
| MRZ Advisors Limited | Administrative & support | 2026 |
| MRZ Consulting Limited | Professional & scientific | 2025 |
| MRZ Properties Limited | Real estate | 2024 |
| MSC Services London Ltd | Other services | 2020 |
| MSD Solutions UK Ltd | Professional & scientific | 2012 |
| Msdc Technologies Ltd | Information & communication | 2018 |
| MSJ Medical Limited | Health & social care | 2018 |
| Mskent Enterprise Ltd | Health & social care | 2022 |
| MSP Lawn Care Ltd | Administrative & support | 2023 |
| MSR Operations Ltd | Other services | 2021 |
| MSS (Steel Services) Ltd | Manufacturing | 2010 |
| Msvel Engineering Ltd | Professional & scientific | 2026 |
| MT Moriah Ltd | Information & communication | 2025 |
| Mtkl Group Limited | Water & waste | 2019 |
| MTR Group Limited | Wholesale & retail | 2011 |
| MTS Kitchen Ltd | Hospitality | 2025 |
| MTS Lane Ltd | Real estate | 2023 |
| Mtwumasi Ltd | Construction | 2015 |
| MUD Island Brewing Co. Ltd | Manufacturing | 2022 |
| Muddy Pots Ltd | Wholesale & retail | 2026 |
| Mudianne Healthcare Limited | Health & social care | 2023 |
| Mugmetal UK Ltd | Construction | 2020 |
| MUH Consultancy Limited | Professional & scientific | 2020 |
| Muhammad Azeem & Sons Limited | Construction | 2024 |
| MUI Koko Limited | Hospitality | 2024 |
| Mulaverse Ltd | Real estate | 2021 |
| Mulberry Green Construction Ltd | Construction | 2019 |
| Multi Ideal Limited | Other services | 2021 |
| Multipro Handymen Ltd | Construction | 2021 |
| MUN (UK) Limited | Education | 2007 |
| Munchy's Vapes Limited | Wholesale & retail | 2022 |
| Munro Instruments Limited | Manufacturing | 2009 |
| Munya West Tradings Ltd | Other services | 2017 |
| Muojicare Medicals Limited | Health & social care | 2017 |
| MUR KAY Ltd | Manufacturing | 2022 |
| Murad Associates Ltd | Transport & logistics | 2019 |
| Murarasu Ltd | Construction | 2015 |
| Murray Grove Investments Limited | Real estate | 2022 |
| Murwalls Ltd | Arts & recreation | 2019 |
| Musa Properties Ltd | Real estate | 2019 |
| Music Truck Ltd | Arts & recreation | 2019 |
| Muvic Ltd | Information & communication | 2022 |
| Muyar Trading Ltd | Wholesale & retail | 2020 |
| MVA Conssolution Ltd | Construction | 2021 |
| MVE Properties Ltd | Real estate | 2021 |
| MVS Realtor Ltd | Real estate | 2022 |
| MW Mechanical Engineering Limited | Professional & scientific | 2015 |
| MW Transport & Recovery Specialist Ltd | Transport & logistics | 2018 |
| MWC2 Ltd | Professional & scientific | 2019 |
| MWM Trading Ltd | Wholesale & retail | 2024 |
| My Boba Tea Limited | Hospitality | 2021 |
| My BSL Ltd | Professional & scientific | 2024 |
| My Energy Saving Limited | Information & communication | 2016 |
| My Harlow Market Ltd | Wholesale & retail | 2025 |
| My Itech Services Ltd | Administrative & support | 2008 |
| My Kloset Ltd | Wholesale & retail | 2023 |
| My Pack Limited | Wholesale & retail | 2025 |
| My Premium Finance Ltd | Financial services | 2014 |
| My Secure Garden Ltd | Wholesale & retail | 2023 |
| Myall IT Limited | Information & communication | 2019 |
| Mylee London Limited | Wholesale & retail | 2019 |
| MYM 23 Ltd | Transport & logistics | 2023 |
| Myuniquecurve Ltd | Manufacturing | 2023 |
| MZ Drylining Ltd | Manufacturing | 2025 |
| Mülla Records Ltd | Information & communication | 2022 |
| N Akram Consultancy Ltd | Financial services | 2012 |
| N Akram Homes Ltd | Real estate | 2018 |
| N&A Builds Ltd | Construction | 2025 |
| N&F Global Enterprises Limited | Wholesale & retail | 2025 |
| N&J Daniel Ltd | Information & communication | 2022 |
| N.J.P. Installations Limited | Construction | 2000 |
| N.L.A Care Limited | Health & social care | 2025 |
| N.S Detailing Ltd | Wholesale & retail | 2024 |
| N.S.C. Performance Ltd | Arts & recreation | 2026 |
| N21 Construction Ltd | Real estate | 2021 |
| N22 Construction Limited | Households | 2022 |