| MNT Homeware Ltd | Wholesale & retail | 2020 |
| MO & K Properties Ltd | Real estate | 2026 |
| Moaavi Limited | Wholesale & retail | 2024 |
| Moallim Travels Ltd | Administrative & support | 2025 |
| Moan Ltd | Wholesale & retail | 2024 |
| Moat Property Limited | Real estate | 2021 |
| Moatdr Ltd | Real estate | 2025 |
| Mobeen Home Improvements Ltd | Construction | 2025 |
| Mobile Kiosk Ltd | Wholesale & retail | 2026 |
| Mobile Mechanic Berkshire Ltd | Wholesale & retail | 2024 |
| Mobile Tyre Heros Limited | Wholesale & retail | 2026 |
| Mobile Tyres Nationwide Ltd | Wholesale & retail | 2025 |
| MOBILE247TYRES Ltd | Wholesale & retail | 2023 |
| Mobileape Ltd | Wholesale & retail | 2023 |
| Mobility (UK) Holdco Limited | Financial services | 2026 |
| Mobility (UK) Opco Limited | Professional & scientific | 2026 |
| Mobs Corporation Limited | Real estate | 2020 |
| Mobuy Limited | Manufacturing | 2018 |
| Mocanu D&D Construction Ltd | Construction | 2023 |
| Mocha Land Ltd | Wholesale & retail | 2024 |
| Mockba Ltd | Manufacturing | 2016 |
| Model London Limited | Administrative & support | 2025 |
| Modern Construction Management Ltd | Construction | 2024 |
| Modern Management Services Ltd | Wholesale & retail | 2025 |
| Modesta DE Quevedo Ltd | Manufacturing | 2025 |
| Modish Builds Ltd | Construction | 2025 |
| Modivio Limited | Wholesale & retail | 2025 |
| Modv Company Limited | Information & communication | 2024 |
| Moe's Hair & Beauty Ltd | Other services | 2016 |
| MOEEZ05 Ltd | Wholesale & retail | 2025 |
| Moghal Auto Ltd | Administrative & support | 2017 |
| Moh.Group Ltd | Real estate | 2025 |
| Moham JIM Limited | Wholesale & retail | 2025 |
| Mohammad IT Services Ltd | Information & communication | 2022 |
| Mohammadwalidanwari Ltd | Wholesale & retail | 2026 |
| Mohayodeen Limited | Administrative & support | 2012 |
| Mohini Ltd | Real estate | 2025 |
| MOI Red Farnham Ltd | Hospitality | 2018 |
| MOIN786 Ltd | Energy | 2023 |
| Moini Invest Limited | Real estate | 2024 |
| Moizrana Ltd | Wholesale & retail | 2022 |
| Mojar Ltd | Financial services | 2026 |
| Mojeezy Hairdressers Ltd | Other services | 2011 |
| Mojo Bridge Limited | Information & communication | 2023 |
| Mokanto Ltd | Wholesale & retail | 2023 |
| Mokka Beans Ltd | Wholesale & retail | 2022 |
| Moksha Consultancy Services Limited | Information & communication | 2015 |
| Molesey Tech Repair Limited | Information & communication | 2023 |
| Molesey Vape Limited | Wholesale & retail | 2023 |
| Mom's Love S Limited | Public administration | 2022 |
| Momentum Strategy & Technologies Ltd | Professional & scientific | 2019 |
| Momentum Tech UK Ltd | Information & communication | 2014 |
| Momentum Traffic Management Ltd | Administrative & support | 2025 |
| Momi Deco Ltd | Construction | 2012 |
| Momo Darboe Ltd | Health & social care | 2018 |
| Momo Services Ltd | Transport & logistics | 2015 |
| Mona's Beauty Limited | Other services | 2022 |
| Monaciello Limited | Real estate | 2021 |
| Monarch Shah Ltd | Manufacturing | 2016 |
| Mondelink Limited | Wholesale & retail | 2015 |
| Monet Luxury Living Limited | Health & social care | 2020 |
| Money MAP Studio Limited | Professional & scientific | 2026 |
| Money+Art Ltd | Professional & scientific | 2013 |
| Moneytree Payroll Services Ltd | Financial services | 2020 |
| Moneywise Consulting Limited | Professional & scientific | 1995 |
| Monicho Ltd | Manufacturing | 2021 |
| Monicons Ltd | Information & communication | 2022 |
| Monomatte Ltd | Wholesale & retail | 2020 |
| Monostori Property Limited | Real estate | 2025 |
| Monpazier Medical Ltd | Health & social care | 2017 |
| Monroe Bar/Kitchen Ltd | Arts & recreation | 2026 |
| Montagu Mews (Datchet) Management Company Limited | Households | 2017 |
| Montagu Road Management Limited | Households | 2007 |
| Montana Bakery Limited | Manufacturing | 1997 |
| Monte Foods Ltd | Hospitality | 2023 |
| Montem Motors Ltd | Wholesale & retail | 2024 |
| Montgate Technologies Limited | Other services | 2018 |
| Montis Homes Ltd | Real estate | 2024 |
| Montrass Limited | Professional & scientific | 1964 |
| Monza Ltd | Wholesale & retail | 2026 |
| Moodlings Ltd | Manufacturing | 2025 |
| Moody Direct (Group Holdings) Limited | Financial services | 2024 |
| Moody Direct (Holdings) Limited | Professional & scientific | 2013 |
| Moody Direct (Investments) Limited | Financial services | 2015 |
| Moody Direct Limited | Manufacturing | 2000 |
| Mooka Ventures Limited | Information & communication | 2024 |
| Moon & NAZ Limited | Transport & logistics | 2020 |
| Moon 1 Ltd | Hospitality | 2022 |
| Moon Builders Ltd | Construction | 2021 |
| Moon Costumes Ltd. | Administrative & support | 2017 |
| Moon Employment Ltd | Administrative & support | 2022 |
| Moon Mart Limited | Wholesale & retail | 2022 |
| Moon Oyster Ltd. | Professional & scientific | 1988 |
| Moonello Ltd | Wholesale & retail | 2022 |
| Moonlight Home Bedding Ltd | Wholesale & retail | 2026 |
| Moonlight Travel Ltd | Administrative & support | 2019 |
| Moore IS Better (MIB) Limited | Construction | 2015 |
| Mopel UK Limited | Construction | 2022 |
| More Space Building Solutions Ltd | Construction | 2023 |
| Moreanu DAC Ltd | Transport & logistics | 2019 |