| Mirror Maker Studios PVT Ltd | Arts & recreation | 2016 |
| Mission Care Management | Health & social care | 1999 |
| Mission Care Trading Limited | Hospitality | 2014 |
| MIX Labs Distribution Ltd | Wholesale & retail | 2019 |
| MIX Labs UK Ltd | Wholesale & retail | 2018 |
| Mixlabs UK CBD Ltd | Wholesale & retail | 2025 |
| MKM Wealth Limited | Real estate | 2021 |
| MKO Commodity Ltd | Professional & scientific | 2025 |
| Mmkm Architecture and Interiors Limited | Professional & scientific | 2017 |
| Mobiconverts Ltd | Administrative & support | 2002 |
| Modeliq Ltd | Professional & scientific | 2025 |
| Modified Specification Products Limited | Construction | 2024 |
| Moley Metals Ltd | Manufacturing | 2021 |
| Monali Travel Ltd | Administrative & support | 2018 |
| Money POT Ltd | Financial services | 2019 |
| MONOPOLY1 Ltd | Other services | 2025 |
| Monterey Digital Ltd | Information & communication | 2025 |
| Monterosa Holdings Ltd | Financial services | 2025 |
| Moonlight Cuisine Limited | Hospitality | 2019 |
| Moreton Estates Limited | Real estate | 2008 |
| Morgan Kerr Ltd | Construction | 2025 |
| Morrell Limited | Information & communication | 1998 |
| Mortgage Evolution Ltd | Financial services | 2019 |
| Mottingham Hall Limited | Health & social care | 2013 |
| Mottingham Managements Limited | Other services | 1998 |
| Mountfield Management Company Limited | Households | 1995 |
| Movo Accelerator Limited | Financial services | 2019 |
| Movo Camps Limited | Professional & scientific | 2023 |
| Movo Croydon Limited | Financial services | 2018 |
| Movo Events Ltd | Financial services | 2023 |
| Movo Glamorgan Ltd | Financial services | 2018 |
| Movo Glasgow Limited | Financial services | 2021 |
| Movo Group Limited | Financial services | 2022 |
| Movo H&L Limited | Professional & scientific | 2022 |
| Movo Health & Life Ltd | Financial services | 2010 |
| Movo Holdings Limited | Financial services | 2022 |
| Movo HQ Limited | Real estate | 2023 |
| Movo INS Broker Holdings Limited | Professional & scientific | 2021 |
| Movo Investment Group Limited | Professional & scientific | 2016 |
| Movo Limited | Professional & scientific | 2024 |
| Movo Orpington Limited | Financial services | 2018 |
| Movo Partnership Ltd | Financial services | 2018 |
| Movo Professional Risks Ltd | Financial services | 2020 |
| Movo Properties Limited | Real estate | 2018 |
| Movo Reading Ltd | Financial services | 2021 |
| Movo Woking Ltd | Financial services | 2022 |
| MPS Product Consulting Limited | Professional & scientific | 2020 |
| MSL Enterprise Ltd | Real estate | 2025 |
| Mubarak Foundation | Administrative & support | 2025 |
| Mudhar Medical Ltd | Health & social care | 2022 |
| Muex Limited | Information & communication | 2020 |
| Muftal's Accountancy Limited | Professional & scientific | 2008 |
| Mulhem Ltd | Health & social care | 2023 |
| Munch Films Ltd | Information & communication | 2014 |
| Munchkins for ALL CIC | Education | 2022 |
| Munchkinsports Ltd | Education | 2024 |
| Munn Enamelling Ltd | Arts & recreation | 2023 |
| Murphy London Communications Ltd | Professional & scientific | 2020 |
| Murray Management Ltd | Real estate | 2024 |
| Musegrove Inns Limited | | 1984 |
| Mushers Garage Ltd | Wholesale & retail | 2014 |
| Music and YOU Ltd | Health & social care | 2019 |
| Music Militia Entertainment Ltd | Administrative & support | 2023 |
| My Tribe Homes Ltd | Health & social care | 2021 |
| Mybabyboulevard Limited | Manufacturing | 2025 |
| Myconbri Ltd | Real estate | 2025 |
| Myoffers Trustees Limited | Professional & scientific | 2019 |
| Mysave Limited | Construction | 2012 |
| Mysave Residential Properties Limited | Financial services | 2015 |
| N & P Heating Services Ltd | Construction | 2012 |
| N 3 a Ltd | Administrative & support | 2012 |
| N.C. Williams Limited | Construction | 2002 |
| Naam Consulting Limited | Professional & scientific | 2017 |
| Naden Dobson Properties Limited | Real estate | 2023 |
| National Risk Solutions Ltd | Financial services | 2019 |
| Nationwide Window and Gutter Cleaning Ltd | Administrative & support | 2020 |
| Nautica Limited | Real estate | 2019 |
| Nazley Limited | Hospitality | 2017 |
| NE Car Cosmetics Ltd | Wholesale & retail | 2023 |
| Nede Hair Care Ltd | Manufacturing | 2021 |
| Neil Williams Limited | Information & communication | 2006 |
| Nerumed Ltd | Health & social care | 2025 |
| Nest & Necessities Limited | Wholesale & retail | 2023 |
| Neuralfusion Ltd | Professional & scientific | 2019 |
| Neurism Limited | Health & social care | 2019 |
| Neverending Solutions Ltd | Professional & scientific | 2021 |
| New Beauty by Alice Ltd | Other services | 2020 |
| New Caledonian Interiors Limited | Wholesale & retail | 2003 |
| New Foundations Day Nursery Limited | Education | 2003 |
| New Paradigm Limited | Construction | 2019 |
| New to Netball Ltd. | Arts & recreation | 2025 |
| Newspace Builders Limited | Construction | 2011 |
| Newtable Restaurant Limited | Hospitality | 2006 |
| Newval Limited | Real estate | 2021 |
| Nexa Consultancy Ltd | Information & communication | 2025 |
| Nexclix Limited | Wholesale & retail | 2025 |
| Next Generation Day Nursery (Barnehurst) Limited | Education | 2017 |
| NEZ Corporation Limited | Real estate | 2016 |
| NFA WTF Ltd | Real estate | 2025 |
| Nick Bygate Advisory Ltd | Professional & scientific | 2026 |