| Mljb Enterprises Limited | Other services | 2019 |
| MLS Assets Ltd | Real estate | 2023 |
| MLT Tyres Ltd | Wholesale & retail | 2019 |
| MM Bawtry Ltd | Hospitality | 2023 |
| MM Invest Ltd | Construction | 2022 |
| MM Prop Consultancy Limited | Professional & scientific | 2015 |
| MM Vapes Limited | Wholesale & retail | 2025 |
| MMA Play 365 Ltd | Information & communication | 2020 |
| MMC Housing Solutions Limited | Construction | 2021 |
| MMC Solid Wall Structures Limited | Construction | 2019 |
| Mmch Care Services Limited | Professional & scientific | 2025 |
| MMD Leisure Limited | Arts & recreation | 2023 |
| MMG Solutions Limited | Manufacturing | 2006 |
| MMK Logistics Limited | Transport & logistics | 2019 |
| Mmkb Trading Ltd | Administrative & support | 2026 |
| Mmkd Holdings Ltd | Financial services | 2014 |
| MMM Trans Ltd | Transport & logistics | 2019 |
| Mmmianany Limited | Health & social care | 2024 |
| MMS Lounge Limited | Hospitality | 2025 |
| MMS Strategic Solutions Ltd | Information & communication | 2026 |
| Mmsmakes Limited | Manufacturing | 2024 |
| Mmtt Limited | Water & waste | 2026 |
| Mmvs Group Ltd | Professional & scientific | 2025 |
| MNA Holdings Limited | Financial services | 2019 |
| Mneme Systems Ltd | Information & communication | 2026 |
| MNL Bargains Ltd | Wholesale & retail | 2026 |
| Mnoise Limited | Health & social care | 2021 |
| Mntd Investments Limited | Extraterritorial | 2022 |
| MO Bar Ltd | Hospitality | 2023 |
| Mo-Haulage Ltd | Transport & logistics | 2026 |
| Mobile & Vape Corner Ltd | Wholesale & retail | 2026 |
| Mobile Doctor & Vape Limited | Wholesale & retail | 2025 |
| Mobile Getaways Limited | Other services | 2025 |
| Mobile Nation(Uk) Ltd | Information & communication | 2016 |
| Mobile Paradise Doncaster Ltd | Wholesale & retail | 2023 |
| Mobilepartsbase Limited | Wholesale & retail | 2025 |
| Mobility House Limited | Wholesale & retail | 2018 |
| Mobility Services (Doncaster) Limited | Health & social care | 2011 |
| Mobri Homes Ltd | Construction | 2024 |
| Mocab Property Limited | Real estate | 2023 |
| MOD Property Development Ltd | Real estate | 2024 |
| MOD Property Rentals Ltd | Real estate | 2024 |
| Modebola Group Limited | Wholesale & retail | 2024 |
| Modern Engineering Services Ltd | Information & communication | 2023 |
| Modern Methods Engineering Consultants Ltd | Professional & scientific | 2013 |
| Modern Property Service (MPS) Ltd | Construction | 2023 |
| Modern Tax & Accounting Solutions Ltd | Professional & scientific | 2026 |
| Modernist Estates Limited | Real estate | 2024 |
| Modlux Lighting Limited | Wholesale & retail | 2025 |
| Modulo 3D Limited | Manufacturing | 2017 |
| Modus Property Limited | Extraterritorial | 2015 |
| MODUS7 Consulting Ltd | Extraterritorial | 2024 |
| Moduvan Ltd | Manufacturing | 2023 |
| Mohawk Pigeon Ltd | Arts & recreation | 2018 |
| Moirae Creative Limited | Information & communication | 2016 |
| Moisi Daniel Transport Ltd | Transport & logistics | 2019 |
| Mojo Cafe Limited | Hospitality | 2020 |
| Mojo Services Ltd | Other services | 2020 |
| Mojoe Financial Coaching Ltd | Professional & scientific | 2025 |
| Mola Aziz Ltd | Hospitality | 2025 |
| Molaro Limited | Health & social care | 2026 |
| Moldo Logistics Ltd | Transport & logistics | 2022 |
| Molly & Tilly (Catering) Ltd | Hospitality | 2019 |
| Molly Consultancy Europe Ltd | Professional & scientific | 2025 |
| Moma Holding Limited | Financial services | 2020 |
| Moments by Shagufa Ltd | Hospitality | 2023 |
| Momentum Delivery Solutions Ltd | Transport & logistics | 2024 |
| Momentum Realty Group Ltd | Real estate | 2025 |
| Momoh's Medical Ltd | Health & social care | 2025 |
| Momosan & Co. Limited | Wholesale & retail | 2014 |
| MON Bebe Photography Limited | Professional & scientific | 2023 |
| Mona & Elissa Ltd | Transport & logistics | 2021 |
| Monalisa Eternal Beauty Massage Ltd | Health & social care | 2025 |
| Monarque Limited | Wholesale & retail | 2018 |
| Monarque Noir Limited | Wholesale & retail | 2024 |
| Monckton Leisure Limited | Hospitality | 2021 |
| Monckton Spaldington Ltd | Hospitality | 2023 |
| Monish Rajagopal UK Ltd | Construction | 2019 |
| Monk Technologies Ltd | Information & communication | 2021 |
| Monkey MAN Media Limited | Professional & scientific | 2022 |
| Monochrome Business Solutions Limited | Education | 2013 |
| Monocon International Refractories Limited | Manufacturing | 1973 |
| Monocon Overseas Limited | Professional & scientific | 1997 |
| Monpellier Venture Ltd | Other services | 2010 |
| Monroe Property Management Ltd | Construction | 2025 |
| Monster Car Wash and Tyres Limited | Wholesale & retail | 2021 |
| Monster Conversions Limited | Manufacturing | 2022 |
| Monster Garage Limited | Wholesale & retail | 2026 |
| Monster Parts Limited | Wholesale & retail | 2024 |
| Montrose Food & Wine Limited | Wholesale & retail | 2012 |
| MOO Creative Ltd | Information & communication | 2023 |
| MOO LAB (DON) Ltd | Hospitality | 2019 |
| Moolah Technologies Ltd | Information & communication | 2025 |
| MOONA1 Limited | Hospitality | 2013 |
| Moonchild and Ocean Ltd | Health & social care | 2023 |
| Moonlight Song Limited | Professional & scientific | 2025 |
| Moor Pizza Limited | Hospitality | 2024 |
| Moorcare Medical Ltd | Health & social care | 2024 |
| Moore Farm Services Limited | Manufacturing | 2010 |
| Moore GAP Investments Limited | Real estate | 2023 |