| Lower Parkgate Residents Ltd | Administrative & support | 2011 |
| LR Talent Ltd | Administrative & support | 2025 |
| Lubeck Investments Limited | Real estate | 2014 |
| Lucky Seven Eight Ltd | Other services | 2015 |
| Lucrum Five Capital Ltd | Real estate | 2020 |
| Lugana Properties Limited | Real estate | 2022 |
| Lumero Educational Trust | Education | 2011 |
| Lunar Riality Ltd | Information & communication | 2025 |
| Lunora Limited | Professional & scientific | 2025 |
| Lust Racing Ltd. | Wholesale & retail | 2009 |
| Luxe Leather Crafts Ltd | Wholesale & retail | 2024 |
| LW Design Consultancy Ltd | Professional & scientific | 2023 |
| Lyght | Financial services | 2025 |
| M and a Cleaners Ltd | Administrative & support | 2018 |
| M L Plumbing and Building Services Ltd | Construction | 2026 |
| M&R Investments Limited | Real estate | 2017 |
| M&S Communications Limited | Manufacturing | 1999 |
| M&Z Bros Ltd | Hospitality | 2025 |
| M.Axell Stone Restoration Limited | Administrative & support | 2017 |
| M.S.S (Micro Scientific Services) Limited | Wholesale & retail | 2014 |
| MA Sound Design Limited | Information & communication | 2023 |
| Mackenzie Shaw Ltd | Construction | 2012 |
| Mackley Care Limited | Health & social care | 2025 |
| MAD Fish Developers Limited | Information & communication | 2024 |
| Made by Water Ltd | Administrative & support | 2010 |
| Magicai Ltd | Professional & scientific | 2026 |
| Magus IT Consulting Ltd | Information & communication | 2017 |
| Mahtems Ltd | Information & communication | 2009 |
| Maison Maroc Limited | Wholesale & retail | 2018 |
| Major Healthcare Ltd | Health & social care | 2021 |
| Making YOU Achieve Ltd | Information & communication | 2020 |
| Mandev Enterprises Ltd | Construction | 2023 |
| Manku Programmes Limited | Information & communication | 2014 |
| Manor Fields Managed Land Limited | Households | 1993 |
| Manor Park Drinks Ltd. | Wholesale & retail | 2014 |
| Manor Park Road Trustee 1 Limited | Extraterritorial | 2008 |
| Manor Park Road Trustee 2 Limited | Extraterritorial | 2008 |
| Manor Way Residents Association Limited | Administrative & support | 1987 |
| Manorstyle Limited | Households | 1983 |
| Manyeri Limited | Hospitality | 2023 |
| Marchant Capital Ltd | Real estate | 2026 |
| Marial Associates Ltd | Education | 2016 |
| Marial Consulting Limited | Professional & scientific | 2019 |
| Marial Estates Limited | Real estate | 2024 |
| Marial Lingua Ltd | Professional & scientific | 2020 |
| Mark Mann Communications Ltd | Professional & scientific | 2019 |
| Maroche Ltd | Information & communication | 2011 |
| Marokka Design Limited | Professional & scientific | 2019 |
| Marri Jann Ltd | Administrative & support | 2007 |
| Marrington Contract Services Limited | Transport & logistics | 2023 |
| Marshall Administration Services Ltd | Health & social care | 2010 |
| Mary & Mick Ltd | Arts & recreation | 2003 |
| Mascarenhas PR Limited | Professional & scientific | 2013 |
| Mashur Somaj Seba Limited | Health & social care | 2015 |
| Mathieson Maher Ltd | Education | 2016 |
| Matrix 4G Ltd | Information & communication | 2014 |
| Matthew Couper Limited | Administrative & support | 2008 |
| Matthew Southgate Golf Ltd | Arts & recreation | 2018 |
| Maveric Group Ltd | Wholesale & retail | 2016 |
| MAX Options Limited | Financial services | 2014 |
| Maxolex Limited | Construction | 2016 |
| Maxwell Construction Limited | Construction | 2025 |
| Maxwell Residents Association Limited | Households | 1981 |
| Maywhit Fit Food Ltd | Hospitality | 2018 |
| Mazar Finance Ltd | Financial services | 2018 |
| MB Lifestyle Ltd | Other services | 2019 |
| MC Agency Limited | Administrative & support | 2016 |
| MD Skincare Ltd | Health & social care | 2017 |
| Mdev Developments Ltd | Real estate | 2024 |
| Mdmr Partners Ltd | Professional & scientific | 2025 |
| MDR Recovery Ltd | Other services | 2024 |
| Mdrn Group Limited | Information & communication | 2019 |
| Mead Road Allotments Ltd | Arts & recreation | 2019 |
| Meccanico Ltd | Construction | 2020 |
| Mediaura Health Ltd | Health & social care | 2025 |
| Medical Surgical Alliance LLP | | 2019 |
| Meedia Limited | Information & communication | 2014 |
| Melburay Clinic Limited | Health & social care | 2025 |
| Melburay Ltd | Health & social care | 2019 |
| Melburay Properties Ltd | Real estate | 2024 |
| Melbury Grange Management Company Limited | Households | 1982 |
| Meldent Ltd | Health & social care | 2026 |
| Meliora Accounting & Advisory Limited | Professional & scientific | 2024 |
| Melissa 34 Limited | Hospitality | 2013 |
| Melno Ltd | Professional & scientific | 2026 |
| Melon Bytes Limited | Information & communication | 2014 |
| MET Foods Limited | Manufacturing | 2017 |
| MFP Capital Ltd | Real estate | 2019 |
| MGB Developments South East Ltd | Construction | 2025 |
| Midas Building Contractors Limited | Construction | 2020 |
| Midas Construction Services Limited | Construction | 2020 |
| Midland Contour Clinic Ltd | Other services | 2022 |
| Midland Contour Clinic Shapewear Ltd | Other services | 2026 |
| Miffa Group Limited | Other services | 2019 |
| Milestones Property LLP | | 2015 |
| Mills Family Limited | Health & social care | 1998 |
| Millstone Broker Services Limited | Financial services | 2022 |
| Minerva Line Limited | Administrative & support | 2005 |
| Miniwhale Studio Ltd | Wholesale & retail | 2024 |
| Mirabelle Food Ltd | Hospitality | 2022 |