| Morton Countrywide Limited | Real estate | 2012 |
| Morton Lodge Developments Limited | Real estate | 2019 |
| Mosaic Jewish Community Limited | Other services | 2013 |
| Mosaic Masorti Synagogue | Other services | 1999 |
| Mosaic Reform Synagogue | Other services | 2013 |
| MOT Training School Ltd | Education | 2021 |
| Mother Baking Cakes Limited | Manufacturing | 2020 |
| Mother Land Hub Ltd | Information & communication | 2024 |
| Motion One Ltd | Information & communication | 2015 |
| Motor Logistik Limited | Construction | 2016 |
| Moudi Limited | Real estate | 2000 |
| Mount 21 Limited | Real estate | 2023 |
| Mount One Ltd | Construction | 2021 |
| Mountain View Consultants Limited | Professional & scientific | 2013 |
| Mountbatten 11 Limited | Real estate | 2021 |
| Mountbatten Homes Real Estate Limited | Real estate | 2017 |
| Mountbatten Real Estate Management Limited | Real estate | 2022 |
| Mountsides Accountants Limited | Professional & scientific | 2017 |
| Mountsides Payroll Bureau Limited | Professional & scientific | 2019 |
| Moura Transport Ltd | Transport & logistics | 2025 |
| Movement Metrics Community Interest Company | Professional & scientific | 2015 |
| Movex Solutions Ltd | Other services | 2023 |
| Mowbray House Ltd | Construction | 2022 |
| MOY Homes Limited | Construction | 2006 |
| MP Land Ltd | Construction | 2019 |
| Mp&Ws Ltd | Information & communication | 2024 |
| MPC Drylining Construction Ltd | Construction | 2021 |
| Mpex Ltd | Health & social care | 2023 |
| MPH 3 Limited | Real estate | 2023 |
| MPH1 Limited | Real estate | 2021 |
| Mpsco Ltd | Financial services | 2020 |
| MR BRN Ltd | Wholesale & retail | 2026 |
| MR Broom Cleaning Services Ltd | Administrative & support | 2024 |
| MR K Trading Limited | Arts & recreation | 2018 |
| MR Kamboj Builder Limited | Construction | 2025 |
| Mrey Limited | Construction | 2018 |
| MRK Holdings Ltd | Real estate | 2020 |
| MRK Phronesis Limited | Education | 2023 |
| Mrmf Ltd | Professional & scientific | 2020 |
| Mrume Ltd | Wholesale & retail | 2026 |
| MS Ergon Limited | Construction | 2017 |
| MSD Network Ltd | Construction | 2026 |
| Msgk Ltd | Wholesale & retail | 2024 |
| Mshp Consulting Limited | Information & communication | 2019 |
| MSK 9 Limited | Real estate | 2007 |
| MSN Osteopath Ltd | Health & social care | 2006 |
| MSN Vehicle Solutions Ltd | Wholesale & retail | 2026 |
| Mspl Ltd | Hospitality | 2025 |
| MSS Ventures Limited | Real estate | 2026 |
| Msskk Limited | Real estate | 2019 |
| MTS Import Cars Ltd | Wholesale & retail | 2021 |
| MTS Solutions Ltd | Real estate | 2023 |
| MTU Partners LLP | | 2019 |
| Mubarak Events Decor Ltd | Hospitality | 2017 |
| Mueller Kneer Associates Limited | Professional & scientific | 2004 |
| Mulcom Limited | Wholesale & retail | 2007 |
| Mumbai Central Limited | Hospitality | 2015 |
| Muna Dahir Ltd | Information & communication | 2024 |
| Munster Limited | Real estate | 1998 |
| Murat Group Ltd | Wholesale & retail | 2025 |
| Murji Properties Limited | Real estate | 2020 |
| Murray Mechanical Services Limited | Construction | 2022 |
| Mursal Boutique Ltd | Other services | 2022 |
| Muscat Developments Ltd | Construction | 2018 |
| Musgrave House Hujjat Limited | Construction | 2025 |
| Music Box Retail Limited | Wholesale & retail | 2013 |
| Music GB LLP | | 2009 |
| Music Video Distributors Europe Limited | Manufacturing | 2005 |
| Musical Moves C.I.C. | Arts & recreation | 2006 |
| Muza Management Ltd | Real estate | 2024 |
| MV Enterprises Ltd | Real estate | 2018 |
| MV Innovation Consulting Ltd | Information & communication | 2021 |
| MVG Trading Ltd | Wholesale & retail | 2026 |
| MVP London Limited | Professional & scientific | 2019 |
| MVR Contracts Limited | Construction | 2007 |
| MVS Property Partnership Limited | Real estate | 2016 |
| MW & SF Holdings Limited | Other services | 2023 |
| MWB Digital Ltd | Information & communication | 2021 |
| My Conviction to Travel Ltd | Professional & scientific | 2025 |
| My Digital Mentors Ltd | Professional & scientific | 2017 |
| My Indemnity Limited | Extraterritorial | 2024 |
| My Kind Ltd | Information & communication | 2020 |
| My Lahore Stanmore Ltd | Hospitality | 2021 |
| My Local Builder Ltd | Construction | 2023 |
| My Local Electrician & Builder 24/7 Limited | Construction | 2021 |
| My Mate Limited | Real estate | 2019 |
| My Mummy's Market Ltd | Wholesale & retail | 2025 |
| My Pearl Ltd | Wholesale & retail | 2025 |
| My Property Hub Trading Limited | Real estate | 2022 |
| My Self Health Check Limited | Health & social care | 2020 |
| MY360CONSTRUCTION Ltd | Construction | 2019 |
| MYA Realty Partners Limited | Real estate | 2017 |
| MYA Software Ltd | Information & communication | 2005 |
| Mydialog Limited | Information & communication | 2018 |
| Myparker Limited | Administrative & support | 2017 |
| Myriad Evolvement Limited | Administrative & support | 2013 |
| Mystyc Pizza Limited | Wholesale & retail | 2018 |
| MZ Talent Group Ltd | Administrative & support | 2024 |
| Mzuri Consultancy Ltd | Information & communication | 2021 |
| N and N Facilities Management Limited | Administrative & support | 2017 |