| Madalina Trans Ltd | Transport & logistics | 2025 |
| Made by JEM Ltd | Hospitality | 2025 |
| Made by Made Limited | Professional & scientific | 2020 |
| Made Electrical Contractors Ltd | Construction | 2021 |
| Mademoisellethai Ltd | Health & social care | 2019 |
| Madesimplecleans Ltd | Administrative & support | 2025 |
| Madhu Construction Ltd | Construction | 2019 |
| Madina Properties (Kent) Limited | Real estate | 2023 |
| Madlove Millcan Holdings Ltd | Wholesale & retail | 2021 |
| Madoka Kogirima Hair Design Ltd | Other services | 2025 |
| Madras Curries Private Limited | Hospitality | 2018 |
| Maegrace Property Ltd | Real estate | 2025 |
| Mafass Limited | Financial services | 2024 |
| Magic Bakers Gravesend Ltd | Hospitality | 2026 |
| Magic Web Solutions Limited | Information & communication | 1999 |
| Maha Private Ltd | Wholesale & retail | 2024 |
| Mahadev Cash and Carry Ltd | Wholesale & retail | 2022 |
| Mahendar Kumar Ltd | Construction | 2026 |
| Maher Property Management Ltd | Real estate | 2020 |
| Mahn Estates Limited | Real estate | 2016 |
| Maholsell Ltd | Wholesale & retail | 2021 |
| Maia Lifting Solutions Ltd | Construction | 2023 |
| Maidstone Grab Hire Ltd | Construction | 2015 |
| Maidstone Smart Trading Ltd | Wholesale & retail | 2019 |
| Maincast Limited | Wholesale & retail | 2022 |
| Mainstone Property Investment Limited | Real estate | 2019 |
| Maison DE Maison Ltd | Real estate | 2025 |
| MAJ & Sons Grill Ltd | Hospitality | 2026 |
| MAJ Consultant Limited | Professional & scientific | 2022 |
| Majd Supermarket Ltd | Wholesale & retail | 2025 |
| Majestic Ceilings Ltd | Construction | 2022 |
| Major Lift Services Ltd | Construction | 2018 |
| Major Minor Car Body Repairs Limited | Wholesale & retail | 2023 |
| Make Management Consulting Limited | Real estate | 2006 |
| Makelogic Limited | Information & communication | 2025 |
| Makoro Electrical,Mechanical,Facilities & Maintenance Services Ltd | Professional & scientific | 2016 |
| Maks Global Foods Limited | Hospitality | 2020 |
| Maku Obuobi Consulting Ltd | Administrative & support | 2017 |
| Malaika Services Limited | Administrative & support | 2015 |
| Malanga Investments Ltd | Real estate | 2025 |
| Malden Trust Limited(The) | Education | 1963 |
| Maldon Food Limited | Hospitality | 2025 |
| Malhotra Properties Ltd | Real estate | 2017 |
| Malidan Ltd | Wholesale & retail | 2018 |
| Malini Trend Ltd | Wholesale & retail | 2025 |
| Malkah Beauty Boudoir Limited | Manufacturing | 2026 |
| Mallagreenspice Limited | Hospitality | 2025 |
| Mallaji Limited | Hospitality | 2025 |
| Mallucci Mayfair Limited | Health & social care | 2022 |
| Malui Consulting Ltd | Information & communication | 2021 |
| MAN I Corp Ltd. | Wholesale & retail | 2024 |
| MAN Maid Services Ltd | Construction | 2021 |
| Management of Belvedere Court Limited | Households | 1996 |
| Managesolutions Ltd | Professional & scientific | 2007 |
| Manapura Ltd | Wholesale & retail | 2024 |
| Mand (PLS) Ltd | Construction | 2009 |
| Mand Group (UK) Ltd | Financial services | 2017 |
| Mango Property Solutions Ltd | Real estate | 2010 |
| Mangold Way Homes Limited | Real estate | 2026 |
| Mangrove Consulting Limited | Professional & scientific | 2005 |
| Manhattan Asset Management Limited | Wholesale & retail | 2009 |
| Manhattan Holdings Ltd | Real estate | 2019 |
| Manifest Agency Ltd | Professional & scientific | 2025 |
| Manikgonj Zela Somiti UK | Other services | 2017 |
| Mankobo Enterprises Limited | Public administration | 2023 |
| Manna Grace Ltd | Real estate | 2025 |
| Mannav Estates Limited | Real estate | 2024 |
| Manning P & E Ltd | Extraterritorial | 2023 |
| Mannpro Ltd | Wholesale & retail | 2022 |
| Manny Consulting Ltd | Professional & scientific | 2025 |
| Manor Livery Limited | Construction | 2025 |
| Mansfield Automotive Ltd | Wholesale & retail | 2023 |
| Mansfield Property Development Ltd | Construction | 2013 |
| Mansfield Property Maintenance Limited | Construction | 2006 |
| Mantlesolutions Ltd | Information & communication | 2022 |
| Manu Pandey Limited | Information & communication | 2019 |
| Manumagin Limited | Education | 2023 |
| Manumagin Properties Limited | Real estate | 2025 |
| Manutenglobal UK FM Limited | Construction | 2024 |
| MAP Windows Ltd. | Construction | 2015 |
| Maple Leaf Kitchens & Bedrooms Limited | Administrative & support | 2010 |
| Maplewood Carpentry Limited | Construction | 2002 |
| MAR Building Services Ltd | Construction | 2024 |
| MAR Ductwork Ltd | Energy | 2021 |
| Maraki Beach Ltd | Administrative & support | 2020 |
| Marathon Print Services Limited | | 1985 |
| Marbek Stone Ltd | Real estate | 2024 |
| Marble Arch Group Limited | Real estate | 2017 |
| Marcella & Associate Ltd | Professional & scientific | 2020 |
| March Safety Training Ltd | Professional & scientific | 2021 |
| Marclindaf Limited | Education | 2022 |
| Marcus (SRT) Properties Ltd | Real estate | 2022 |
| Margaf Ltd | Transport & logistics | 2014 |
| Margel PVT Ltd | Health & social care | 2011 |
| Maria Pride Limited | Health & social care | 2013 |
| Mariana Trench Ltd | Information & communication | 2025 |
| Mariani UK & Ireland Ltd | Professional & scientific | 2011 |
| Marigold Catering Solutions Limited | Construction | 2017 |
| Marigold Engineers Limited | Manufacturing | 2011 |
| Marin 1 Ltd | Transport & logistics | 2016 |