| MRS Mopp Cleaning Services (UK) Limited | Extraterritorial | 2011 |
| MRT Garage Group Limited | Wholesale & retail | 2024 |
| MS Stays Ltd | Real estate | 2024 |
| MSA Anywhere Ltd | Transport & logistics | 2017 |
| MSD Law Limited | Information & communication | 2019 |
| MSF Fitness Limited | Arts & recreation | 2013 |
| MSG Trans Ltd | Transport & logistics | 2025 |
| MSM Hire Ltd | Construction | 2015 |
| MSM Plant Ltd | Manufacturing | 2005 |
| MSO Chauffeur Ltd | Transport & logistics | 2025 |
| MSR Building & Landscaping Ltd | Administrative & support | 2023 |
| MT Industrial Supplies Limited | Wholesale & retail | 2024 |
| MTB Adventures Limited | Administrative & support | 2022 |
| MTE Freelance Ltd | Professional & scientific | 2024 |
| MTJ Automotive Ltd | Wholesale & retail | 2015 |
| MTM Visuals Ltd | Information & communication | 2023 |
| Much More Books Limited | Wholesale & retail | 2004 |
| Muckleton Storage Ltd | Administrative & support | 2024 |
| Muench Holdings Ltd | Other services | 2021 |
| Muench Ltd | Other services | 2021 |
| Mulberry Homes Railway Inn Flat Management Company Limited | Real estate | 2006 |
| Mulgi Ltd | Other services | 2019 |
| Mullock's Ltd | Wholesale & retail | 2009 |
| Multi Utilities Ltd | Construction | 2021 |
| Multicore Services Ltd | Water & waste | 2025 |
| Mumbai Lounge Limited | Hospitality | 2016 |
| Munce Prpperty Ltd | Real estate | 2026 |
| Munif' Social Care Limited | Health & social care | 2012 |
| Murax Ltd | Administrative & support | 2020 |
| Murray Farms Limited | Agriculture & fishing | 2013 |
| Must Management Training Essentials Limited | Extraterritorial | 2022 |
| Mutlu Fish & Chips Ltd | Hospitality | 2023 |
| Muxton Funeral Services Limited | Professional & scientific | 2013 |
| Muxton Properties Limited | Real estate | 2025 |
| MV Distribution Limited | Wholesale & retail | 2024 |
| Mvirk Transport Ltd | Transport & logistics | 2024 |
| Mvit Cons Limited | Information & communication | 2023 |
| MW Medics Ltd. | Health & social care | 2017 |
| MW Service & Installations Limited | Construction | 2015 |
| MWP Creative Ltd | Professional & scientific | 2022 |
| My Learning (UK) Ltd | Information & communication | 2009 |
| My Little Play Place Telford Ltd | Arts & recreation | 2024 |
| My LOW Carbon Limited | Construction | 2023 |
| My Mosi Ltd | Professional & scientific | 2023 |
| My Outfit Limited | Wholesale & retail | 2013 |
| My Pizza Plus Ltd | Hospitality | 2019 |
| My Property Hub Limited | Financial services | 2015 |
| My Sister's Closet Ltd | Wholesale & retail | 2014 |
| My Sourcing Hub Ltd | Information & communication | 2018 |
| My UK Taxi Ltd | Wholesale & retail | 2024 |
| My... Kicks! Ltd | Extraterritorial | 2026 |
| Mybloc Tech Limited | Information & communication | 2026 |
| Mycroft Solutions Limited | Information & communication | 2000 |
| Myers Rentals Ltd | Households | 2022 |
| Myres 02 Limited | Arts & recreation | 2025 |
| Mysports and More Holdings Limited | Administrative & support | 2020 |
| Mysports and More Limited | Wholesale & retail | 2016 |
| Mystic Cave Ltd | Extraterritorial | 2026 |
| Mytchel RAM Ltd | Arts & recreation | 2026 |
| Mytton Consulting Ltd | Information & communication | 2017 |
| N & B Phillips Limited | Construction | 2019 |
| N & E AV Ltd | Information & communication | 2025 |
| N B Independent Scaffold Services Ltd | Construction | 2017 |
| N Bradshaw Heating Services Ltd | Construction | 2022 |
| N D Heeley Plastering Ltd | Other services | 2011 |
| N Dimensions Limited | Other services | 2017 |
| N Dugmore Limited | Education | 2013 |
| N M Homer Limited | Professional & scientific | 2025 |
| N W Print Ltd | Manufacturing | 2012 |
| N.E.O. Decorations Ltd | Construction | 2018 |
| N1 Danny’S Barber Ltd | Other services | 2025 |
| Naad Limited | Public administration | 2022 |
| Nabeel Shop Ltd | Wholesale & retail | 2026 |
| Nad-Speed Ltd | Transport & logistics | 2014 |
| Nadakals Ltd | Health & social care | 2016 |
| Nadeem Solutions Ltd | Public administration | 2022 |
| Naked Lime Developments Ltd | Real estate | 2026 |
| Name Paytech Solutions Consulting Ltd | Financial services | 2017 |
| Namulas Pension Trustees Limited | Financial services | 1970 |
| Nana Delivers Ltd | Transport & logistics | 2025 |
| Nanny's Craft Bakery Limited | Manufacturing | 2018 |
| Nanyuki Engineering Limited | Professional & scientific | 2017 |
| Nardolilli Ltd | Wholesale & retail | 2022 |
| Narvas Ltd | Other services | 2020 |
| Nashcabs Ltd | Transport & logistics | 2026 |
| Nashional Events Limited | Administrative & support | 2025 |
| Nasice Ltd | Other services | 2019 |
| Nasit Ltd | Other services | 2019 |
| Nathan Holder Property Group Ltd | Real estate | 2025 |
| Nathon Legal Services Shropshire Limited | Administrative & support | 2007 |
| National Bovine Data Centre Ltd | Agriculture & fishing | 2016 |
| National Caravan Recovery & Repairs Ltd | Wholesale & retail | 2026 |
| National Platforms Ltd | Administrative & support | 2019 |
| National Translation Services Limited | Professional & scientific | 2021 |
| Nationwide Services Group Limited | Water & waste | 2001 |
| Natural Selection Foods Limited | Manufacturing | 2012 |
| NAV Food Service Ltd | Hospitality | 2023 |
| Naxium Ltd | Administrative & support | 2019 |
| NAZ Halal Meat Ltd | Wholesale & retail | 2026 |
| Nazaré Logistics Ltd | Transport & logistics | 2025 |