| Maipro Consultancy Ltd | Real estate | 2014 |
| Mair Consultancy Ltd | Wholesale & retail | 2005 |
| Maisie Grace Limited | Wholesale & retail | 2022 |
| Maitlands Acorn Professional Limited | Professional & scientific | 2004 |
| Majak Limited | Administrative & support | 2017 |
| Majisense Technologies Limited | Manufacturing | 2026 |
| Major Engineering Ltd | Professional & scientific | 2015 |
| Majorboost Residents Management Limited | Real estate | 1987 |
| Makaveli Protection Limited | Construction | 2021 |
| Make IT Your Design Ltd | Professional & scientific | 2020 |
| Makpro Coaching Limited | Education | 2026 |
| Malinga Ltd | Health & social care | 2019 |
| Mallington House (Camberley) M. C. Limited | Households | 2000 |
| Malloy Aeronautics Limited | Manufacturing | 2012 |
| Malone Sports Limited | Arts & recreation | 2013 |
| Mama's Pizza Centre Limited | Hospitality | 2024 |
| MAN & Co (UK) Limited | Professional & scientific | 1998 |
| MAN Healthcare UK Ltd | Health & social care | 2015 |
| Management Brigade Ltd | Professional & scientific | 2018 |
| Mandalay Media Ltd | Information & communication | 2023 |
| Mandmade Ltd | Manufacturing | 2017 |
| MANGO12 Ltd | Wholesale & retail | 2026 |
| Manikaran Enterprises Limited | Wholesale & retail | 2025 |
| Manning Impex Limited | Wholesale & retail | 1987 |
| Manning Stainton Conveyancing Limited | Extraterritorial | 2017 |
| Manning Stainton Rentals and Property Management Limited | Real estate | 1993 |
| Mano Mano Ltd | Real estate | 2025 |
| Manor Farm (Darby Green Lane) Residents Management Company Limited | Administrative & support | 2002 |
| Manor Farm Land (Tongham) Ltd | Real estate | 2019 |
| Manordale Properties Ltd | Real estate | 2021 |
| Mantra Care Homes Limited | Health & social care | 2012 |
| Maolog Ltd | Information & communication | 2021 |
| Maple Garden Landscape Design Limited | Extraterritorial | 2024 |
| Maple Tree Carpentry & Renovations Ltd | Construction | 2018 |
| Maplehurst (West Drive) Management Limited | Households | 2023 |
| Mapridge Design Studios Limited | Professional & scientific | 2017 |
| Marble Hall Services Ltd | Health & social care | 2020 |
| Marc Daniel (Camberley) Limited | Other services | 2010 |
| Marcus Webb Associates Limited | Administrative & support | 2015 |
| Mard Foods Ltd | Wholesale & retail | 2025 |
| Marios Consulting Group Ltd | Professional & scientific | 2025 |
| Mark Scarbrow Ltd | Administrative & support | 2019 |
| Mark Wallinger Landscapes Limited | Administrative & support | 2007 |
| Markhall Limited | Real estate | 1992 |
| Markham Court RTM Company Limited | Households | 2011 |
| Marlborough Gardens (North Leigh) Management Company Limited | Households | 2020 |
| Marlborough Gate Management Company Limited | Households | 1998 |
| Marlins Land and Development Ltd | Real estate | 2012 |
| Marshall & Mace Limited | Construction | 2006 |
| Marstan Place (Camberley) Management Company Limited | Households | 2012 |
| Mary Phillips Ltd | Health & social care | 2024 |
| MAS Collection Limited | Wholesale & retail | 2018 |
| Mastang Group Ltd | Wholesale & retail | 2022 |
| Masters Electrical Contractors Ltd | Construction | 2008 |
| Mastory Ltd | Education | 2025 |
| Mat-Kris Limited | Transport & logistics | 2017 |
| Mattei On-Vehicle Energy Ltd | Manufacturing | 1986 |
| Mattson Ltd | Construction | 2015 |
| Matunda Limited | Real estate | 2022 |
| Matériel Connectivity Ltd | Information & communication | 2026 |
| Matériel Ltd | Information & communication | 2024 |
| Maultway Gate Management Company Limited | Households | 2004 |
| Mauritius Flavours Limited | Hospitality | 2021 |
| Maurosie Investments Limited | Real estate | 2020 |
| Mawrag Limited | Real estate | 2025 |
| Maximum Velocity Water Treatment Ltd | Water & waste | 2023 |
| Maxplan Limited | Administrative & support | 1974 |
| Mayamomo Ltd | Hospitality | 2024 |
| Maybury Hill (Woking) Management Company Limited | Households | 2008 |
| Mayer Ashley Limited | Real estate | 2026 |
| Mayer Green Limited | Real estate | 2022 |
| Mayer Property Holding Limited | Real estate | 2026 |
| Mayflower Court (Reading) Residents Association Limited | Households | 1996 |
| Maytrics Limited | Construction | 2014 |
| MB Clean Scent Service Ltd | Administrative & support | 2024 |
| MB Design Services Limited | Professional & scientific | 2002 |
| MBM Foods Services Ltd | Hospitality | 2019 |
| MBM Real Estates Ltd | Real estate | 2024 |
| MBM Used Cars for Sales Ltd | Wholesale & retail | 2024 |
| MBP Fitness Limited | Arts & recreation | 2013 |
| MC Squared Capital Limited | Professional & scientific | 2019 |
| MCA Data Analytics Ltd | Information & communication | 2022 |
| Mccarron Associates Limited | Administrative & support | 2013 |
| Mccarthy Holden (Odiham) Limited | Real estate | 2004 |
| Mccarthy Holden (Property Management) Limited | Real estate | 2004 |
| Mccarthy Holden Limited | Real estate | 1993 |
| Mccartney Investments Ltd | Construction | 2025 |
| Mccx Ltd | Professional & scientific | 2014 |
| Mcdermott & Sons Limited | Information & communication | 2005 |
| Mcguinness Feeds Limited | Wholesale & retail | 2024 |
| MCM 24 Limited | Administrative & support | 2021 |
| Mcmanov Ltd | Construction | 2020 |
| Mcmanus Smith Ltd | Professional & scientific | 2026 |
| MCN Accounting Limited | Professional & scientific | 2013 |
| MCN Oxford Ltd | Construction | 2023 |
| MCS Associates Ltd | Professional & scientific | 2022 |
| Mdhair Limited | Other services | 2017 |
| Mdhairandscalp Ltd | Other services | 2022 |
| ME Pure Beauty Ltd | Other services | 2022 |
| Me&P Interiors Limited | Professional & scientific | 2019 |