| Modern London Eyewear Ltd | Wholesale & retail | 2017 |
| Modernkind Ltd | Wholesale & retail | 2024 |
| Modify Ltd | Professional & scientific | 2018 |
| Modiman Property Ltd | Construction | 2026 |
| Modn Metl Ltd | Information & communication | 2018 |
| Modstation Ltd | Wholesale & retail | 2019 |
| Modular Grills Limited | Manufacturing | 2026 |
| Mofinity Global Limited | Information & communication | 2021 |
| Mohamed Osman & Co Limited | Information & communication | 2022 |
| Mohde Studios Ltd | Information & communication | 2025 |
| Moiz Services Limited | Professional & scientific | 2023 |
| Mokimoo Limited | Wholesale & retail | 2025 |
| Moli UK Limited | Information & communication | 2025 |
| Mollis Capital Limited | Real estate | 2025 |
| Molly's Boutique Ltd | Wholesale & retail | 2025 |
| Mollys Properties Limited | Real estate | 2022 |
| Moments Events and Hire Limited | Administrative & support | 2023 |
| Monarch AG Ltd | Financial services | 2024 |
| Monarch Collection Ltd | Hospitality | 2024 |
| Monaughty Bloodstock Limited | Agriculture & fishing | 2015 |
| Monaughty Property Limited | Financial services | 2021 |
| Mondo Property Ltd | Real estate | 2025 |
| Money Solutions Limited | Other services | 2023 |
| Monitherm Limited | Manufacturing | 1998 |
| Monitraders Ltd | Wholesale & retail | 2024 |
| Monitry Ltd | Information & communication | 2026 |
| Monkey Spanner ERP Solutions Ltd | Administrative & support | 2017 |
| Mono Mirrors Ltd | Wholesale & retail | 2026 |
| Monochrome Property Ltd | Real estate | 2023 |
| Monostar Limited | Information & communication | 1988 |
| Monovo Limited | Manufacturing | 2025 |
| Monoweave Ltd | Wholesale & retail | 2025 |
| Monster Deals Ltd | Health & social care | 2015 |
| Monsters Inc Limited | Other services | 2017 |
| Montigny Ltd | Other services | 2022 |
| Monyow Ltd | Professional & scientific | 2026 |
| Monyprop Ltd | Real estate | 2026 |
| Monytech Ltd | Information & communication | 2026 |
| Moon Body Ltd | Health & social care | 2023 |
| Moon Nest Ltd | Wholesale & retail | 2026 |
| Moonbeam Designs Ltd | Wholesale & retail | 2016 |
| Moonhead Limited | Wholesale & retail | 2018 |
| Moonlets Investments Ltd | Real estate | 2026 |
| Moonrise Properties Ltd | Real estate | 2025 |
| Moontlik Limited | Information & communication | 2026 |
| Moonwell Leaseholds Ltd | Real estate | 2025 |
| Moonwell Management Ltd | Households | 2025 |
| Moorcroft Beds Ltd | Manufacturing | 2023 |
| Moore Finance Partners Ltd | Professional & scientific | 2024 |
| Moores Transport (Suffolk) Limited | Transport & logistics | 2006 |
| Moorlands PUB Company Ltd | Hospitality | 2021 |
| Moors Marketing Ltd | Professional & scientific | 2020 |
| Moosa Real Estate and Investment Group Ltd | Other services | 2023 |
| Morashershah Ltd | Administrative & support | 2025 |
| Moray Data Ltd | Information & communication | 2026 |
| More Than Culture Ltd | Wholesale & retail | 2025 |
| Morebakes&Co Limited | Hospitality | 2025 |
| Moretime Ventures Ltd | Real estate | 2023 |
| Moreton Hall Barbers Ltd | Other services | 2025 |
| Moreton Hall Club Ltd | Arts & recreation | 2021 |
| Moreton Hall Glass (Bury ST. Edmunds) Limited | Construction | 2005 |
| Moreton Hall School Limited | Other services | 1962 |
| Moreton Hall Youth Action Group Ltd | Other services | 2005 |
| Moreton MEN Sports Group CIC | Arts & recreation | 2025 |
| Morgan Energy Ltd | Construction | 2021 |
| Morgan O'Flynn Criminal Justice Consultancy Limited | Health & social care | 2009 |
| Morgan Securities Limited | Professional & scientific | 1980 |
| Moriarty's Restaurants Limited | Hospitality | 2018 |
| Moroccan Discovery Limited | Administrative & support | 2016 |
| Moroccan Living Rooms Limited | Wholesale & retail | 2017 |
| Morphie Tech Ltd | Wholesale & retail | 2020 |
| Morphisyn File Logic Limited | Manufacturing | 2026 |
| Morrish & Partners Limited | Professional & scientific | 1998 |
| Morshed Enterprises Ltd | Wholesale & retail | 2024 |
| Mortec Electrical Ltd | Manufacturing | 2025 |
| Morten Environmental Strategies Ltd | Professional & scientific | 2024 |
| Morton Electrics Ltd | Wholesale & retail | 2026 |
| Morz Wholesale Ltd | Wholesale & retail | 2026 |
| Moses Martin OPS Ltd | Information & communication | 2023 |
| Mostyn Holdings Limited | Real estate | 2024 |
| Mother Truffler Limited | Hospitality | 2024 |
| Motherlyease Ltd | Wholesale & retail | 2023 |
| Motion Driven Autos Ltd | Wholesale & retail | 2026 |
| Motionomics Ltd | Professional & scientific | 2023 |
| Motionplm Limited | Information & communication | 2019 |
| Motive Solutions Limited | Wholesale & retail | 2026 |
| Moto Cinch UK Ltd | Wholesale & retail | 2023 |
| Motogeek Ltd | Wholesale & retail | 2025 |
| Motorflow Developments Limited | Wholesale & retail | 2022 |
| Motortrade AI Ltd | Professional & scientific | 2025 |
| Mount Bank Farm Limited | Agriculture & fishing | 2015 |
| Mount Pleasant Ducks Limited | Agriculture & fishing | 2004 |
| Mountain Motorsport Ltd | Wholesale & retail | 2024 |
| Mountcay Wind Limited | Professional & scientific | 2001 |
| Mountshannon Technology Ltd | Information & communication | 2018 |
| Mousai Academy Ltd | Information & communication | 2018 |
| Move With Intent Limited | Transport & logistics | 2025 |
| MOVE6 Ltd | Information & communication | 2025 |
| Moveme Students Ltd | Transport & logistics | 2024 |
| Movepark Ltd | Extraterritorial | 2023 |