| Mother Goose Mortgages Ltd | Financial services | 2007 |
| Motion Accountancy Limited | Professional & scientific | 2014 |
| Motion Advisory Limited | Professional & scientific | 2025 |
| Motion Creative Limited | Professional & scientific | 2025 |
| Motion Lifts Limited | Professional & scientific | 2014 |
| Motiongrid Limited | Professional & scientific | 2015 |
| Motobox Classic UK Limited | Wholesale & retail | 2018 |
| Motobox UK Ltd | Wholesale & retail | 2014 |
| Motor Hero Ltd | Wholesale & retail | 2019 |
| Motor Trade Talent Limited | Administrative & support | 2025 |
| Mount Ephraim Court Limited | Households | 1992 |
| Mount Ephraim Property Ltd | Real estate | 2026 |
| Mount Lodge Residents Association Limited | Real estate | 1991 |
| Mountain OR Sea Limited | Hospitality | 2016 |
| Move With Yasmin Ltd | Arts & recreation | 2018 |
| Movemind Limited | Real estate | 1996 |
| MP Human Resources Ltd | Administrative & support | 2016 |
| MP Payroll Solutions Limited | Professional & scientific | 2004 |
| Mpactdelta Consulting Ltd | Professional & scientific | 2018 |
| Mpath Ltd | Construction | 2005 |
| MPI Associates Limited | Professional & scientific | 2009 |
| MPM Solutions UK Limited | Administrative & support | 2004 |
| MPO (UK) Limited | Manufacturing | 1996 |
| MPO Consultants Ltd | Professional & scientific | 2015 |
| MPRO5 EBT Limited | Information & communication | 1991 |
| MR With MRS Cleaning Ltd | Administrative & support | 2022 |
| MR Zorba Ltd | Hospitality | 2024 |
| MR. Beans Coffee Shop Limited | Wholesale & retail | 2024 |
| MR. Blue Ltd | Wholesale & retail | 2024 |
| MR. Mattin Plus Ltd | Wholesale & retail | 2025 |
| Mrcpch Courses Limited | Education | 2013 |
| MRE Research Ltd | Information & communication | 2025 |
| MRG Insights Ltd | Professional & scientific | 2025 |
| MRS Florist Tunbridge Wells Limited | Wholesale & retail | 2016 |
| MRS G-D Interiors Limited | Wholesale & retail | 2016 |
| Ms&S UK Properties Limited | Real estate | 2024 |
| MS. Editor Ltd | Wholesale & retail | 2021 |
| MSD Commerce Ltd | Wholesale & retail | 2026 |
| MSN Beauty Salon Limited | Other services | 2026 |
| MSS Agile Services Ltd | Information & communication | 2015 |
| Mstech Consulting Limited | Information & communication | 2014 |
| MTA Digital Solutions Ltd | Information & communication | 2022 |
| MTB Computer Services (UK) LLP | | 2008 |
| MTF Capital Ltd | Professional & scientific | 2020 |
| Mtpropertycare Ltd | Construction | 2024 |
| MUD HUT Marketing Limited | Professional & scientific | 2011 |
| Muffett Holdings Limited | Professional & scientific | 2017 |
| Muhib Limited | Extraterritorial | 2007 |
| Multi Skip Hire Ltd | Construction | 2018 |
| Mulwells Ltd | Real estate | 2025 |
| Mum's the Word Limited | Administrative & support | 2016 |
| Munro Technical Services Ltd | Construction | 2025 |
| Muon Studios Limited | Arts & recreation | 2016 |
| Murdered OUT Motors Limited | Wholesale & retail | 2018 |
| Murphy's Magpies Ltd | Health & social care | 2026 |
| Murray & Phelan(Holdings)Limited | Professional & scientific | 1964 |
| Music for Life Encore Ltd | Education | 2025 |
| Musical Theatre Productions LLP | | 2009 |
| Mustard Accounts Ltd | Administrative & support | 2002 |
| Mutated Metamorphosis Limited | Other services | 2020 |
| Muvement Ltd | Professional & scientific | 2025 |
| MV Creative Consulting Ltd | Professional & scientific | 2024 |
| MW Plus Limited | Real estate | 2024 |
| MW Stables Ltd | Agriculture & fishing | 2026 |
| MW4 QS Ltd | Construction | 2019 |
| MWP Consulting Limited | Professional & scientific | 2025 |
| My Business Saved Ltd | Professional & scientific | 2020 |
| My HR Community Limited | Administrative & support | 2022 |
| My Lusso Casa Ltd | Wholesale & retail | 2026 |
| My Own Adventure Limited | Wholesale & retail | 2012 |
| My Venturescape Limited | Real estate | 2020 |
| My-Wheelbarrow Community Interest Company | Professional & scientific | 2026 |
| Mykagami Limited | Information & communication | 2020 |
| Mylonite Consulting Ltd | Administrative & support | 2019 |
| Mynetwork Ltd | Wholesale & retail | 2012 |
| Myrevisionary Ltd | Information & communication | 2026 |
| Myriad Construction Limited | Construction | 2011 |
| Mytin Limited | Construction | 2014 |
| MZ Motorsport Ltd | Wholesale & retail | 2026 |
| Mz&F Capstone Consulting Limited | Financial services | 2026 |
| Mz&F Capstone Investment Limited | Financial services | 2026 |
| Mz&F Capstone Real Estate Limited | Real estate | 2026 |
| MZ9 Sports Ltd | Arts & recreation | 2021 |
| Müge Turner Ltd | Manufacturing | 2026 |
| N & H DL Properties Limited | Real estate | 2017 |
| N & K Glover Ltd | Administrative & support | 2020 |
| N S Davey Ltd | Information & communication | 2026 |
| N&D Cars Services Ltd | Transport & logistics | 2024 |
| N16 Communications Ltd | Information & communication | 2024 |
| Naaris & Co Limited | Wholesale & retail | 2021 |
| NAB Consulting Ltd | Administrative & support | 2016 |
| Nacnud Investments Limited | Real estate | 2016 |
| Nadine Powrie Consultancy Limited | Other services | 2016 |
| Nail Lounge Tunbridge Ltd | Other services | 2026 |
| Nails Crush Ltd | Other services | 2023 |
| Naimus Studio Limited | Information & communication | 2025 |
| Naive Communications Limited | Information & communication | 2020 |
| Nanny Caddie Ltd | Information & communication | 2018 |
| Nanosoft Homes Limited | Real estate | 2020 |
| Nanosoft Limited | Information & communication | 2015 |