| More Than Lease (Cheshire) Limited | Wholesale & retail | 2013 |
| Morely Trends Ltd | Wholesale & retail | 2022 |
| Moreways Consulting Limited | Professional & scientific | 2017 |
| Morgana London Ltd | Wholesale & retail | 2025 |
| Morningside (Altrincham) RTM Company Limited | Households | 2005 |
| Mornington Supply Ltd | Wholesale & retail | 2020 |
| Morra Limited | Professional & scientific | 2011 |
| Morris Dibben Limited | Professional & scientific | 2004 |
| Morris Supply Chain Limited | Professional & scientific | 2026 |
| Morrison Building Group Limited | Real estate | 1986 |
| Morrison Services Limited | Professional & scientific | 2022 |
| Morro Bay Company Limited | Information & communication | 2025 |
| Mortgage Next Packaging Limited | Professional & scientific | 2007 |
| Mortimer Khan Medical Communications Limited | Information & communication | 2024 |
| Morton Jones Ltd | Administrative & support | 2025 |
| Mosa Consulting Limited | Professional & scientific | 2026 |
| Mosaic Tax Chambers Ltd | Professional & scientific | 2023 |
| Moshie Limited | Real estate | 2010 |
| Moss Lane Management Company Limited | Households | 2003 |
| Moss Pottery Studio Ltd | Manufacturing | 2023 |
| Moten Ltd | Health & social care | 2013 |
| Mother Theresa Private Limited | Public administration | 2022 |
| Mottingus Limited | Professional & scientific | 2026 |
| Mottram Hall Farm Management Company Limited | Households | 2002 |
| Moulding Capital Newco Limited | Professional & scientific | 2021 |
| Mount Hira Group Ltd | Education | 2020 |
| Mountain Top Media Limited | Information & communication | 2024 |
| Mountford Limited | Professional & scientific | 1985 |
| Mountie Holdings Limited | Administrative & support | 2015 |
| Mountskape Limited | Mining & quarrying | 2015 |
| Mountview Communications Limited | Professional & scientific | 2021 |
| Mourad Consultancy Ltd | Health & social care | 2022 |
| Mouro Coffee Ltd | Wholesale & retail | 2024 |
| Mousavy Offshore Limited | Administrative & support | 2011 |
| MOVE2MUSIC Limited | Education | 2025 |
| Moving Forward Consultancy Limited | Health & social care | 2022 |
| Moyas SAI Limited | Health & social care | 2015 |
| Moyas SAI Properties Ltd | Real estate | 2018 |
| Moyo Aviation Services Limited | Manufacturing | 2019 |
| MP Global Assist Ltd | Transport & logistics | 2023 |
| MP Medical Practice Management Limited | Administrative & support | 2016 |
| MPA Properties & Investments Ltd | Real estate | 2025 |
| MPB Services Ltd | Construction | 2025 |
| Mpch Fraction UK Ltd | Information & communication | 2021 |
| MPF Soho Funding Limited | Financial services | 2020 |
| MPO Marketing Limited | Professional & scientific | 2025 |
| Mprice Consulting Limited | Professional & scientific | 2024 |
| MR a Spot Cleaning Limited | Administrative & support | 2024 |
| MR BEN Rahuma Ltd | Education | 2026 |
| MR Bidco 1 Ltd | Financial services | 2025 |
| MR Bidco 2 Ltd | Financial services | 2025 |
| MR Bidco 3 Ltd | Financial services | 2026 |
| MR Bidco 4 Ltd | Financial services | 2026 |
| MR Darren Hughes Ltd | Professional & scientific | 2012 |
| MR Holdco 3 Ltd | Financial services | 2026 |
| MR Holdco 4 Ltd | Financial services | 2026 |
| MRC Gynaecology Limited | Health & social care | 2016 |
| MRF Law Limited | Financial services | 2024 |
| MRF Legal Limited | Financial services | 2021 |
| MRG Dental Limited | Health & social care | 2023 |
| MRO Consulting Limited | Administrative & support | 2023 |
| Mrtlconsulting Ltd | Education | 2025 |
| MS (a) NOM1 Limited | Professional & scientific | 2020 |
| MS (a) NOM2 Limited | Professional & scientific | 2020 |
| MS (C) NOM1 Limited | Professional & scientific | 2020 |
| MS (C) NOM2 Limited | Professional & scientific | 2020 |
| MS (D) NOM1 Limited | Professional & scientific | 2020 |
| MS (D) NOM2 Limited | Professional & scientific | 2020 |
| MS Bhatti Associates Ltd | Health & social care | 2023 |
| MS Tennis Ltd | Arts & recreation | 2025 |
| MS Vehicle Services Ltd | Wholesale & retail | 2022 |
| Ms&D Consulting Limited | Information & communication | 2025 |
| MSB Dental Limited | Health & social care | 2026 |
| MSB IT Limited | Administrative & support | 2018 |
| MSC Actuarial Limited | Professional & scientific | 2021 |
| MSC Building Projects Ltd | Construction | 2018 |
| MSC Fitout Ltd | Construction | 2020 |
| MSC Group (NW) Ltd | Construction | 2020 |
| MSC Software Development Ltd | Information & communication | 2017 |
| Msca Legacy Limited | Other services | 2023 |
| Msfd Properties Ltd | Real estate | 2025 |
| Msjg Limited | Professional & scientific | 2017 |
| MSK Endo Limited | Administrative & support | 2020 |
| Mslt Consultancies Ltd | Professional & scientific | 2023 |
| MSR Windowtech Ltd | Wholesale & retail | 2021 |
| MSW Group Holdings Limited | Construction | 2018 |
| MTC Capital & Investments Ltd | Households | 2021 |
| MTG Global Investments Ltd | Real estate | 2026 |
| Mtit Ltd | Education | 2025 |
| Mtkhn Ltd | Health & social care | 2021 |
| Mughal Take Away Ltd | Hospitality | 2017 |
| Mulans Belgian Bar Ltd | Other services | 2022 |
| Mulberry Estates (Wilmslow) Limited | Construction | 2024 |
| Multi Keys Limited | Real estate | 2021 |
| Multi-Events Ventures Limited | Wholesale & retail | 2020 |
| Multiblend Chemicals Limited | Manufacturing | 1980 |
| Multiflex School Sports Ltd | Education | 2019 |
| Multiworks Marketing Ltd | Administrative & support | 2011 |
| Mumsaloud Initiative CIC | Health & social care | 2020 |
| Municipal Chambers Ltd | Construction | 2023 |