| Mileswaterman Accountants Limited | Professional & scientific | 2012 |
| Mill Reef Investments Ltd | Real estate | 2020 |
| Million Different Ways Ltd | Education | 2026 |
| MIN Kwong Electric (UK) Company Limited | Construction | 2018 |
| Minas 2015 Ltd | Hospitality | 2017 |
| Mind & Self Ltd | Administrative & support | 2017 |
| Mind in Bexley and East Kent Ltd | Health & social care | 2005 |
| MINDS4AI Ltd | Information & communication | 2025 |
| Mindtrack Technologies Ltd | Information & communication | 2017 |
| Ming of the Avenue Catering Ltd | Hospitality | 2024 |
| Mini Family Kingdom Ltd | Real estate | 2026 |
| Minibus Shuttle Services Limited | Transport & logistics | 2025 |
| Mira Gracia Limited | Construction | 2026 |
| Mirash Limited | Wholesale & retail | 1999 |
| Mirchev Building Ltd | Construction | 2024 |
| Mirdin Medical Limited | Health & social care | 2021 |
| Mirons Newsagents Ltd | Wholesale & retail | 2021 |
| Mirror Mirror (Kent) Ltd | Other services | 2013 |
| Mitchell Offshore & Marine Consultants Limited | Professional & scientific | 2015 |
| MIX Grill & Chill Company Limited | Hospitality | 2026 |
| MJM & SON Protective Coatings Limited | Construction | 2017 |
| MK London Investment Ltd | Real estate | 2026 |
| Mlenjosh Ltd | Real estate | 2025 |
| MM Bespoke Interiors Limited | Construction | 2023 |
| MM Property Renovations Ltd | Construction | 2022 |
| MM Refurbish Ltd | Construction | 2025 |
| Mmap Training & Consultancy Ltd | Professional & scientific | 2026 |
| MNM Management Ltd | Real estate | 2021 |
| Moatbrook Ltd | Construction | 2009 |
| Modern Homes (South East) Ltd | Construction | 2024 |
| Mogg Property Services Limited | Real estate | 2017 |
| Moldcom Ltd | Wholesale & retail | 2024 |
| Momo & Co Trading Ltd | Hospitality | 2025 |
| Momo Hub Holding Ltd | Financial services | 2024 |
| Monkey Business Images Limited | Professional & scientific | 2005 |
| Monolith Construction Ltd | Construction | 2013 |
| Monro Accounting Services Limited | Professional & scientific | 2011 |
| Montero Software Ltd | Information & communication | 2024 |
| Moolam Limited | Health & social care | 2014 |
| Moppets Childcare Agency Ltd | Health & social care | 2024 |
| Morayo Gifts Ltd | Wholesale & retail | 2024 |
| Morgan's Funeral Directors Ltd | Other services | 2024 |
| Morland Systems Ltd | Information & communication | 2010 |
| Morris & Associates Accountants Ltd | Professional & scientific | 2011 |
| Mortgagemaze Financial Services Ltd | Professional & scientific | 2006 |
| MOTIV8 Property Group Ltd | Real estate | 2024 |
| Mourya Construction Company Ltd | Construction | 2026 |
| Move Mate Removals Ltd | Water & waste | 2024 |
| Moving UK Homes Limited | Real estate | 2017 |
| MP Drywall Systems Ltd | Construction | 2017 |
| Mr.Kumru Ltd | Information & communication | 2023 |
| Mrinal Technologies Limited | Information & communication | 2011 |
| MRS P'S Hair Ltd | Other services | 2019 |
| MS Perfect Bexleyheath Ltd | Other services | 2024 |
| MS Perfect Sutton Ltd | Other services | 2018 |
| MS. Perfect Ltd | Other services | 2015 |
| MS. Perfect Thamesmead Ltd | Other services | 2017 |
| MSG Property Ltd | Real estate | 2011 |
| MSN Bexley Limited | Manufacturing | 2021 |
| MT Risk Consultants Ltd | Professional & scientific | 2024 |
| MTF Plumbing Limited | Construction | 2013 |
| Mtipson Limited | Administrative & support | 2011 |
| Multi Tech Homes Limited | Construction | 2024 |
| Mumethila Ltd | Arts & recreation | 2016 |
| Muras Construction Ltd | Construction | 2024 |
| Murray Motors Ltd | Wholesale & retail | 2026 |
| MVP Analytics Limited | Information & communication | 2024 |
| Mwlc Ltd | Arts & recreation | 2024 |
| My Butcher & Fish Ltd | Wholesale & retail | 2020 |
| My Go to Agent Limited | Real estate | 2021 |
| My Lily Ltd | Wholesale & retail | 2020 |
| My Muse Wines Ltd | Wholesale & retail | 2022 |
| My New Self Ltd | Arts & recreation | 2023 |
| My Sales Progressor Ltd | Administrative & support | 2023 |
| Mycomeup Media Ltd | Professional & scientific | 2022 |
| Myhappyhome Ltd | Wholesale & retail | 2024 |
| Mytpi Ltd | Construction | 2023 |
| N and N Services Global Limited | Administrative & support | 2025 |
| N Hill Property Limited | Real estate | 2017 |
| N&V Delivery Ltd | Transport & logistics | 2019 |
| N2 Financial Consulting Limited | Information & communication | 2016 |
| N3RD LDN Ltd | Wholesale & retail | 2023 |
| Nadar Properties Limited | Real estate | 2024 |
| Naga Fried Chicken Ltd | Hospitality | 2019 |
| Nails Atelier Ltd | Other services | 2026 |
| Nainoc IT Limited | Information & communication | 2012 |
| Naman Ltd | Health & social care | 2025 |
| Namtech Consulting Ltd | Information & communication | 2012 |
| Nantorex Ltd | Information & communication | 2010 |
| Nasa Accountancy Limited | Professional & scientific | 2019 |
| Natcat Consulting Ltd. | Information & communication | 2017 |
| Nathan Way Garage Limited | Wholesale & retail | 2013 |
| National Mortgage Awards Limited | Administrative & support | 2024 |
| Nationwide Private Hire Operator Network Ltd | Transport & logistics | 2014 |
| NAYA10 Limited | Health & social care | 2020 |
| NBA Properties Limited | Real estate | 2016 |
| Nectar Brands Limited | Information & communication | 2021 |
| Nectra Ltd | Administrative & support | 2025 |
| Neema Limited | Wholesale & retail | 2013 |
| Nefis Mezze Limited | Hospitality | 2026 |