| Mogic (UK) Limited | Information & communication | 2024 |
| Mogu Forklift Parts Co., Ltd | Extraterritorial | 2018 |
| Moke Marine Machinery Hongkong Co., Limited | Manufacturing | 2023 |
| Mol-Chemical Limited | Extraterritorial | 2018 |
| Mollie Page Creative Ltd | Professional & scientific | 2025 |
| Molly Enterprise Ltd | Wholesale & retail | 2023 |
| Molly Moon Productions Ltd | Information & communication | 2012 |
| Momentum Trade Group Limited | Extraterritorial | 2024 |
| Mompiont Ltd | Extraterritorial | 2021 |
| Mona Kiki Limited | Wholesale & retail | 2021 |
| Monaei Beauty Ltd | Other services | 2025 |
| Mono Pump Industry Co., Limited | Manufacturing | 2025 |
| Monrah Consulting Ltd | Professional & scientific | 2013 |
| Monteverdi RP Limited | Wholesale & retail | 2021 |
| Montronix GmbH Limited | Manufacturing | 2021 |
| Moon Pine Trading Co., Ltd | Information & communication | 2025 |
| Moona International Trading Co., Ltd | Extraterritorial | 2023 |
| Moonim & Associates Limited | Health & social care | 2022 |
| Moonlight Family Co., Ltd | Wholesale & retail | 2019 |
| Moonlight Symphony Limited | Transport & logistics | 2021 |
| Moorhunt Investments Ltd | Financial services | 2011 |
| Mooschool Limited | Administrative & support | 2007 |
| Mooti Technologies Ltd | Professional & scientific | 2020 |
| MOR Consulting Limited | Professional & scientific | 2004 |
| Moregmv Trading Ltd | Wholesale & retail | 2026 |
| Moresless Group Ltd | Manufacturing | 2024 |
| Morgan Chase Paul Asset Management Co., Ltd | Extraterritorial | 2018 |
| Morgan Developments & Design Limited | Construction | 2017 |
| Morgan Lewis Developments Limited | Construction | 2015 |
| Morgan Property Maintenance Limited | Construction | 2011 |
| Morgan Stanley Science Investment Limited | Information & communication | 2023 |
| Morgandica Ltd | Mining & quarrying | 2023 |
| Morley Garden Homes Limited | Construction | 2021 |
| Morrie Holdings Limited | Real estate | 2014 |
| Morris & Phalp Ltd | Administrative & support | 2017 |
| Morris Builders Limited | Construction | 2014 |
| Morrison & Co Estates Ltd | Real estate | 2025 |
| MOS & Luczak Printing UK Limited | Manufacturing | 2013 |
| MOS Import and Export Co., Limited | Wholesale & retail | 2020 |
| Mosaic CSE Limited | Professional & scientific | 2014 |
| Mosaic Operative Ltd | Hospitality | 2023 |
| Moshi International Co., Ltd | Professional & scientific | 2015 |
| Mount Arbour Capital Limited | Construction | 2016 |
| Mount Street Partners Ltd | Professional & scientific | 2024 |
| Mountain House Properties Ltd | Real estate | 2023 |
| Mountain Sea Ship Service Co., Ltd | Manufacturing | 2025 |
| Moya Printing Technology (UK) Co., Ltd. | Manufacturing | 2024 |
| Moyo E&C Co., Ltd | Extraterritorial | 2017 |
| Moyuan Trade Co., Limited | Manufacturing | 2019 |
| MP Commercial Services Ltd | Administrative & support | 2006 |
| MPH Bearings Ltd | Manufacturing | 2023 |
| MPS Care Provider Ltd | Health & social care | 2023 |
| MR FIX & Build Ltd | Construction | 2025 |
| MR Frango Grill Ltd | Hospitality | 2023 |
| MR KAY Ltd | Wholesale & retail | 2000 |
| MR Music Ltd | Wholesale & retail | 2023 |
| MR68 Ltd | Professional & scientific | 2026 |
| MRD 22 Limited | Construction | 2025 |
| Mroobest Shop Co., Ltd | Extraterritorial | 2018 |
| MRS Locks Ltd | Wholesale & retail | 2025 |
| Msash Limited | Hospitality | 2023 |
| MSD Machinery Co., Limited | Wholesale & retail | 2005 |
| MSE Consultancy Limited | Professional & scientific | 2009 |
| Mseaco HK Group Co., Ltd | Manufacturing | 2023 |
| Msmk Consultants Ltd | Professional & scientific | 2021 |
| MSN Development Holding Ltd | Real estate | 2022 |
| MSP Concepts Limited | Administrative & support | 2000 |
| Mstech Industrial Group Limited | Wholesale & retail | 2025 |
| Msyaho Cosmetics Co., Ltd | Wholesale & retail | 2021 |
| Mtakta Ltd | Wholesale & retail | 2025 |
| MTT Casey Limited | Arts & recreation | 2017 |
| Mugen International Company Limited | Professional & scientific | 2008 |
| Muirhead-Smith Wealth Management Ltd | Professional & scientific | 2023 |
| Muke Media Co., Ltd | Manufacturing | 2023 |
| Mukta Private Limited | Real estate | 2020 |
| Mulberry Social Ltd | Hospitality | 2024 |
| Mulder International Trade Co., Ltd | Manufacturing | 2020 |
| Mull Solutions Ltd | Manufacturing | 2025 |
| Multi Link Chemicals Co., Ltd. | Manufacturing | 2020 |
| Multimac Group Ltd | Construction | 1981 |
| Multimac Surfaces Limited | Construction | 2021 |
| Multimodal International Ltd | Wholesale & retail | 2022 |
| Multysys Consultants Limited | Information & communication | 1999 |
| Mums Best Picks Ltd | Administrative & support | 2024 |
| Mums Traders Limited | Professional & scientific | 2022 |
| Munot Properties Limited | Real estate | 2015 |
| Munot Services Limited | Other services | 2016 |
| Munro Real Estate Limited | Professional & scientific | 2017 |
| Murcraft Services Limited | Wholesale & retail | 2002 |
| Murphy & Co International Ltd | Professional & scientific | 2024 |
| Murphy Digital Limited | Professional & scientific | 2023 |
| Murtoncole Ltd | Information & communication | 2014 |
| Music Industry Consultants Ltd | Information & communication | 2020 |
| Musical Theatre Masterclass Limited | Arts & recreation | 2016 |
| Musical Theatre UK Limited | Arts & recreation | 2012 |
| Muxi Lighting Co., Ltd | Extraterritorial | 2019 |
| Muzii Furniture Co., Limited | Wholesale & retail | 2021 |
| Mville Limited | Information & communication | 2017 |
| MW Creation Trade Co., Ltd | Extraterritorial | 2014 |
| MX Masterclass Limited | Arts & recreation | 2018 |