| Minerva Private Travel Ltd | Administrative & support | 2000 |
| Minimacreative Ltd | Professional & scientific | 2023 |
| Miriamusic Limited | Information & communication | 1972 |
| Mistree Ltd | Information & communication | 2026 |
| Mitiga Ltd | Information & communication | 2020 |
| Mixfold Limited | Households | 1973 |
| MJJ Rail Recruitment and Hire Ltd | Construction | 2019 |
| ML5 Promotions Limited | Arts & recreation | 2025 |
| MLR IT Consultancy Ltd | Information & communication | 2016 |
| MM10 Limited | Arts & recreation | 2024 |
| MMF Trading and Services Limited | Professional & scientific | 2014 |
| MMP 360 Ltd | Information & communication | 2025 |
| Mobcoder Ltd | Information & communication | 2020 |
| Mobile Notary Register Limited | Information & communication | 2019 |
| Moderncomms Ltd | Information & communication | 2021 |
| Modum Design Ltd | Manufacturing | 2014 |
| Moleshill Ltd | Information & communication | 2021 |
| Monexa AI Labs Ltd | Information & communication | 2025 |
| Monovar Properties Ltd | Real estate | 2018 |
| Montage Properties Limited | Construction | 2022 |
| Montstone Developments Ltd | Construction | 2025 |
| MOO Moo's Play Cafe Limited | Hospitality | 2024 |
| Moonchild Limited | Professional & scientific | 2009 |
| Mooretech (Cobham) Limited | Wholesale & retail | 2017 |
| Moosan Ltd | Other services | 2025 |
| Moosie Limited | Manufacturing | 2013 |
| Morado Homes Ltd | Real estate | 2016 |
| Morane (Cobham) Ltd | Real estate | 2024 |
| Morrill Developments Limited | Administrative & support | 1998 |
| Most Stars Limited | Health & social care | 2012 |
| Mother Lake Minerals Limited | Wholesale & retail | 2025 |
| Motivforce Ltd | Professional & scientific | 2011 |
| Mozeik Ltd | Information & communication | 2022 |
| MPA Commercial Limited | Professional & scientific | 2014 |
| MPA Creative Limited | Professional & scientific | 2008 |
| MPA Events Limited | Professional & scientific | 2020 |
| MPA Promotions Limited | Arts & recreation | 2024 |
| Mpol Ltd | Health & social care | 2016 |
| Mpulumutsi Capital Inc Ltd | Financial services | 2025 |
| MR and MRS a. N. Castle LLP | | 2009 |
| MRK Business Consultants Limited | Professional & scientific | 2025 |
| Msab Management UK Limited | Arts & recreation | 2025 |
| MSC Models Limited | Arts & recreation | 1974 |
| MTD Landlords Limited | Professional & scientific | 2026 |
| Mucs Enterprises Limited | Other services | 2015 |
| Mucs Investments Limited | Financial services | 2021 |
| Muenchinger Limited | Administrative & support | 2013 |
| Mush and Mojo Limited | Wholesale & retail | 2023 |
| Musolab Ltd | Wholesale & retail | 2026 |
| MVA Advisory Limited | Administrative & support | 2019 |
| MVA Associates Limited | Administrative & support | 2020 |
| MVA Mortgages Limited | Financial services | 2024 |
| MWM Consulting Limited | Professional & scientific | 2018 |
| My BI Planet Ltd | Information & communication | 2013 |
| My HR Consultant Limited | Health & social care | 2009 |
| My Life IS My Business Limited | Other services | 2007 |
| Mypacc CIC | Information & communication | 2026 |
| Mystack Ltd | Arts & recreation | 2024 |
| Mystery Esports Jerseys Limited | Wholesale & retail | 2022 |
| Mystic Spice - Curry Limited | Hospitality | 2025 |
| N&N Merton Property Ltd | Real estate | 2024 |
| N2 Asset Management Limited | Financial services | 2018 |
| N2 Developments Limited | Professional & scientific | 2010 |
| N23 Resources Limited | Financial services | 2025 |
| NAD+ Labs Ltd | Health & social care | 2018 |
| Nadar Land Ltd | Real estate | 2025 |
| Nail Spa Cobham Ltd | Other services | 2017 |
| Napoli Fishmongers Ltd | Wholesale & retail | 2025 |
| Napp Ltd | Wholesale & retail | 2023 |
| Nate DEA Limited | Professional & scientific | 2010 |
| Natural Chemicals Ltd | Professional & scientific | 2025 |
| Nature Media Productions Limited | Information & communication | 2013 |
| NC22 Promotions Limited | Arts & recreation | 2023 |
| NC22 Properties Limited | Real estate | 2023 |
| NC22 Property Group Limited | Financial services | 2023 |
| NCO ( PVT) Ltd | Professional & scientific | 2022 |
| NCT Consulting Ltd | Professional & scientific | 2023 |
| Neoventa Medical Limited | Manufacturing | 2008 |
| Ness Road Land Transfer Ltd | Professional & scientific | 2008 |
| Netcom Solutions & Services Ltd | Information & communication | 2010 |
| Neuro & Psych Clinic Limited | Health & social care | 2021 |
| New Homes Limited | Extraterritorial | 2002 |
| New Homes Select Limited | Real estate | 2003 |
| New Page Productions Ltd | Professional & scientific | 2021 |
| New Telecom Express Limited | Professional & scientific | 2004 |
| New Wayve Digital Ltd | Information & communication | 2013 |
| New Yorker Productions Limited | Information & communication | 2013 |
| Newwave Fitness Limited | Arts & recreation | 2014 |
| Newwave Fitness Services Limited | Arts & recreation | 2014 |
| Nexa Automations Ltd | Information & communication | 2025 |
| Nextech Systems Ltd | Information & communication | 2023 |
| NI Design Ltd | Professional & scientific | 2025 |
| Niamh Godley Consulting Ltd | Professional & scientific | 2026 |
| Nicki’S Physio Ltd | Health & social care | 2025 |
| Nico Bouquet Limited | Other services | 2021 |
| Nico Thompson Eyewear Ltd | Wholesale & retail | 2016 |
| Nico Thompson Ltd | Wholesale & retail | 2024 |
| Nicola Dibb Associates Ltd | Professional & scientific | 2013 |
| Nicole Mackintosh Ltd | Health & social care | 2018 |
| Niiap Ltd | Administrative & support | 2025 |