| MNA 566 Limited | Real estate | 2017 |
| MNH Enterprise Ltd | Administrative & support | 2017 |
| MNS Property Services Ltd | Real estate | 2016 |
| MO & Co Barber Limited | Other services | 2025 |
| MO Football Ltd | Arts & recreation | 2025 |
| MO3.O Limited | Real estate | 2025 |
| Moallem Capital & Advisory Ltd | Real estate | 2025 |
| Moaryarty Ltd | Information & communication | 2015 |
| Moazam & Brothers Ltd | Wholesale & retail | 2024 |
| Mobeen Plastics Ltd | Manufacturing | 2026 |
| Mobicafe Ltd | Wholesale & retail | 2020 |
| Mobicloudtrees Ltd | Information & communication | 2016 |
| Mobil House UK Ltd | Wholesale & retail | 2025 |
| Mobile a Vape Limited | Other services | 2020 |
| Mobile Cosmetics Limited | Health & social care | 2014 |
| Mobile Gossip Ltd | Information & communication | 2024 |
| Mobile School of Lighting Design Ltd | Education | 2014 |
| Mobile Shisha Event Limited | Hospitality | 2026 |
| Mobyzone Limited | Information & communication | 2019 |
| Modec Property Ltd | Households | 2014 |
| Modern Careers Ltd | Information & communication | 2010 |
| Modern Design Building Services Ltd | Construction | 2011 |
| Modern Quartz Stone Ltd | Wholesale & retail | 2023 |
| Modern Stone Carpets Ltd | Wholesale & retail | 2012 |
| Modest Missy Ltd | Wholesale & retail | 2021 |
| Modi Real Estates Limited | Real estate | 2021 |
| Modica Marble London Limited | Other services | 2016 |
| Modica Stone Ltd | Construction | 2024 |
| Modular Scope Ltd | Real estate | 2019 |
| Moghimi Properties Limited | Real estate | 2024 |
| Mohamed Qassem Education Services Ltd | Education | 2024 |
| Mojo Roofing Ltd | Construction | 2023 |
| Moksh PVT Ltd | Wholesale & retail | 2022 |
| Moksha Enterprise Limited | Hospitality | 2026 |
| Moloci Ltd | Transport & logistics | 2018 |
| Moloney Management & Consultancy Ltd | Transport & logistics | 2023 |
| Momado Ltd | Health & social care | 2023 |
| Mombasa Motos 001 Ltd | Wholesale & retail | 2026 |
| Moment Apps Ltd | Information & communication | 2024 |
| Momentumclub Ltd | Wholesale & retail | 2026 |
| Momi Development Ltd | Construction | 2024 |
| Momo Touch Limited | Manufacturing | 2025 |
| Monak Limited | Wholesale & retail | 1981 |
| Monaminkedit Limited | Other services | 2024 |
| Monarch A189 Limited | Real estate | 2021 |
| Monarch C APT189 Ltd | Real estate | 2021 |
| Monarch C11 APT189 Limited | Real estate | 2021 |
| Monarch Concept 1 Ltd | Construction | 2018 |
| Monarch Concept Limited | Construction | 2017 |
| Monarch HR80 Ltd | Construction | 2020 |
| Monarch HR80 One Ltd | Real estate | 2021 |
| Monarch Trade Co. Ltd | Wholesale & retail | 2025 |
| Monec UK Ltd | Hospitality | 2025 |
| Money Honey Properties Ltd | Real estate | 2019 |
| Money Wise Services Limited | Other services | 2016 |
| Moni Health Care Limited | Health & social care | 2016 |
| Monika Beauty Studio Limited | Other services | 2015 |
| Monkschem Properties Limited | Real estate | 2019 |
| Monro Investments Ltd | Real estate | 2021 |
| Montaire Ltd | Wholesale & retail | 2026 |
| Montpelier Park Close Management Limited | Real estate | 1986 |
| Monz Autos Ltd | Wholesale & retail | 2026 |
| Monzdecor Ltd | Other services | 2023 |
| Moodys Premium Machines Limited | Wholesale & retail | 2025 |
| Moonbeam Enterprises Limited | Wholesale & retail | 2020 |
| Moonbeam Retail Limited | Administrative & support | 2025 |
| Mooney Estates Ltd | Real estate | 2025 |
| Moonlight DRY Cleaners Ltd | Other services | 2016 |
| Moorcroft Developments Ltd | Construction | 2021 |
| Moore Land Holdings LLP | | 2019 |
| Moore Security Ltd | Administrative & support | 2020 |
| Moorthy Salon Limited | Other services | 2024 |
| Moorway Consultancy Ltd | Professional & scientific | 2011 |
| Moos Group Ltd | Other services | 2023 |
| Moqui Pictures Ltd | Information & communication | 2025 |
| Morden Clinic Limited | Health & social care | 2019 |
| Mordenrise Ltd | Construction | 2025 |
| Mordish Limited | Transport & logistics | 2019 |
| Morgan's Storm Sanctuary Limited | Health & social care | 2025 |
| Morganite Properties Limited | Real estate | 2019 |
| Morhiby Investment Ltd | Real estate | 2021 |
| Morleys Wembley Limited | Hospitality | 2024 |
| Morne Darbeau Limited | Transport & logistics | 2004 |
| Morozone Ltd | Construction | 2016 |
| Morre Lynk Limited | Transport & logistics | 1987 |
| Morris House Surgery Limited | Health & social care | 2007 |
| Morrisland for Asphalt & Concrete Industry Ltd | Manufacturing | 2020 |
| Morston Burslem Limited | Real estate | 2010 |
| Morston Etruria Limited | Real estate | 2011 |
| Mortgage Warehouse Uk.Com Ltd | Administrative & support | 2019 |
| Mosaco Properties Ltd | Real estate | 2021 |
| Mosela Consulting Ltd | Information & communication | 2023 |
| Moss Vision Inc Limited | Professional & scientific | 2006 |
| Mostak Limited | Information & communication | 2010 |
| Mother Goose Childcare Ltd | Education | 2018 |
| Mother Organic Limited | Wholesale & retail | 2021 |
| Motion Estate Ltd | Real estate | 2010 |
| Motion Vehicle Repair Ltd | Wholesale & retail | 2025 |
| Moto Fast UK Ltd | Manufacturing | 2019 |
| Motorise Limited | Wholesale & retail | 2014 |