| Multisport Research Limited | Professional & scientific | 2010 |
| Multiversal Limited | Real estate | 2009 |
| Multiverse Limited | Arts & recreation | 2004 |
| Mum's Makery Limited | Wholesale & retail | 2022 |
| Mumba Consultancy Ltd | Other services | 2022 |
| Mumbai Otley Limited | Hospitality | 2019 |
| Muncaster Construction Ltd | Construction | 2024 |
| Munch House Yate Ltd | Wholesale & retail | 2026 |
| Munchkins Childcare Limited | Health & social care | 2019 |
| Mundial (Bristol) Ltd | Financial services | 2025 |
| Mundial Connections Ltd | Professional & scientific | 2023 |
| Mundy & Anson Ltd | Information & communication | 2017 |
| Mundy SSC Ltd | Construction | 2016 |
| Munford Enterprises Limited | Construction | 2011 |
| Munford Property Holdings Ltd | Real estate | 2022 |
| Muni TAG Ltd | Wholesale & retail | 2025 |
| Munir's E-Shop Ltd | Wholesale & retail | 2025 |
| Munny Detailing & Valeting Limited | Wholesale & retail | 2025 |
| Munro & Forster Holdings Limited | Professional & scientific | 2015 |
| Munyaradzi Healthcare Limited | Health & social care | 2015 |
| Muonex Ltd | Construction | 2025 |
| Murad Prizes Limited | Wholesale & retail | 2024 |
| Muralto House Management Company Limited | Other services | 2002 |
| Murcia Luxury Properties Ltd | Real estate | 2026 |
| Murgatroyd Consulting Ltd | Professional & scientific | 2013 |
| Murmuration Community Therapy CIC | Health & social care | 2020 |
| Murray Clark Accounting Limited | Professional & scientific | 2026 |
| Murray May's Ltd. | Hospitality | 2017 |
| Murray Roach Limited | Professional & scientific | 2010 |
| Murrays Homelets Limited | Real estate | 2014 |
| MUS Kebab House Ltd | Hospitality | 2022 |
| Musa Data Limited | Information & communication | 2022 |
| Musaraza Logistics Limited | Transport & logistics | 2026 |
| Muscat & Co Mortgage Solutions Limited | Professional & scientific | 2014 |
| Muscify Limited | Wholesale & retail | 2023 |
| Muse BR Ltd | Hospitality | 2023 |
| Muse Content Ltd | Arts & recreation | 2026 |
| Muse Services Limited | Administrative & support | 2005 |
| MUSE4MEDIA Limited | Information & communication | 2009 |
| Mushi Worldwide Ltd | Manufacturing | 2022 |
| Mushram Ltd | Information & communication | 2013 |
| Mushtaq Franchise Ltd | Hospitality | 2026 |
| Mushtaq Sweets Bristol Ltd | Wholesale & retail | 2026 |
| Music Plug Co. Ltd | Information & communication | 2025 |
| Music Producer Bible Ltd | Education | 2022 |
| Music With Mummy Limited | Arts & recreation | 2022 |
| Musical Inspiration AI Ltd | Information & communication | 2020 |
| Musii Ltd | Manufacturing | 2010 |
| Muskrat Limited | Real estate | 2002 |
| Mustang Escapes Ltd | Real estate | 2023 |
| Mustang Property Maintenance Ltd | Construction | 2026 |
| Mustang Ranch Limited | Real estate | 2025 |
| Mustard Designs Ltd | Construction | 2023 |
| Mustard Enterprises Limited | Administrative & support | 2009 |
| Mustard Jobs Limited | Administrative & support | 2013 |
| Mustikka Limited | Information & communication | 2012 |
| Mutahijeff Limited | Health & social care | 2013 |
| Muti Immersive Ltd | Education | 2021 |
| Muto's Detailing Services Ltd | Administrative & support | 2025 |
| Mutt Struts Ltd | Wholesale & retail | 2014 |
| Muttley Jones Limited | Construction | 2026 |
| Mutual Care Limited | Health & social care | 2017 |
| Mutual Recruitment Ltd | Administrative & support | 2019 |
| Mutualism Limited | Information & communication | 2019 |
| Muuddey Ltd | Transport & logistics | 2019 |
| Muussa's Limited | Wholesale & retail | 2026 |
| Muyencares Support Ltd | Health & social care | 2025 |
| Muzuni Limited | Financial services | 2014 |
| MV Balmoral Fund Limited | Transport & logistics | 2013 |
| MV Josephine Ltd | Extraterritorial | 2016 |
| MV Service Inc Ltd | Wholesale & retail | 2025 |
| MV Urban Studio Ltd | Professional & scientific | 2025 |
| MVB Solutions Limited | Wholesale & retail | 2023 |
| MVC Promo Ltd | Manufacturing | 2005 |
| MVP Car Rentals Ltd | Administrative & support | 2025 |
| MVP Shipping Ltd. | Transport & logistics | 2021 |
| MVS Autos Ltd | Wholesale & retail | 2011 |
| MVS Autos(Sw) Ltd | Wholesale & retail | 2024 |
| Mvze Consulting Limited | Professional & scientific | 2022 |
| MW Actuarial Services Ltd | Financial services | 2026 |
| MW Content Consultancy Limited | Extraterritorial | 2018 |
| MW Energy Services Ltd | Construction | 2025 |
| MW Funeral Directors Limited | Other services | 2017 |
| MW Lets Ltd | Real estate | 2023 |
| MW Surfacing (South West) Limited | Construction | 2012 |
| MW Weddings & Events Ltd | Administrative & support | 2023 |
| Mwalabu Ltd | Financial services | 2021 |
| Mwanzo Project CIC | Health & social care | 2023 |
| MWF Installation Limited | Construction | 2008 |
| Mwhitford Ltd | Professional & scientific | 2014 |
| Mwilliams Business Services Limited | Professional & scientific | 2022 |
| MWS Advisory Ltd | Information & communication | 2024 |
| MWW Renovations Ltd | Construction | 2021 |
| MX2 Fire and Security Systems Ltd | Administrative & support | 2024 |
| MXL Mews Ltd | Wholesale & retail | 2021 |
| Mxrgroundworks Ltd | Construction | 2025 |
| My Allied Health Limited | Real estate | 2024 |
| My APC Ltd | Education | 2025 |
| My Aqss Ltd | Wholesale & retail | 2024 |
| My Audit Pro Limited | Information & communication | 2017 |