| Mark Glen Consultancy Ltd | Professional & scientific | 2020 |
| Mark Hall IT Services Ltd | Information & communication | 2017 |
| Mark Harrison Ground Maintenance Limited | Administrative & support | 2012 |
| Mark Hendry Music Services Ltd | Education | 2024 |
| Mark Jeffers Boxing Ltd | Arts & recreation | 2021 |
| Mark Lupton Communications Limited | Professional & scientific | 2015 |
| Mark Nissen & SON Limited | Administrative & support | 2008 |
| Mark Pollitt Photography Ltd | Professional & scientific | 2020 |
| Mark Sidebotham Consulting Ltd | Administrative & support | 2026 |
| Markenze Technology Limited | Wholesale & retail | 2025 |
| Market Brunch Limited | Wholesale & retail | 2022 |
| Market Fish Bar Limited | Hospitality | 2005 |
| Market Mobiles Ltd | Wholesale & retail | 2025 |
| Market Quarter Group Limited | Professional & scientific | 2024 |
| Market Weighton Pharmacy Limited | Health & social care | 2012 |
| Marketing at the Front Limited | Information & communication | 2026 |
| Marketplacehospitality Ltd | Hospitality | 2024 |
| Marketvibe&Trend Ltd | Wholesale & retail | 2024 |
| Markk Estates Limited | Real estate | 2022 |
| Markland Complementary Health Limited | Health & social care | 2007 |
| Markland Hill Properties Limited | Real estate | 2026 |
| Markland Therapy Centre Limited | Health & social care | 2018 |
| Marko Mini Market Ltd | Wholesale & retail | 2021 |
| Markose Limited | Health & social care | 2023 |
| Markx Ltd | Wholesale & retail | 2023 |
| Marlans Property Limited | Real estate | 2020 |
| Marlborough Asset Managers Limited | Financial services | 2020 |
| Marlborough Court (Bolton) Management Company Limited | Households | 2002 |
| Marlborough Fund Managers Ltd. | Financial services | 1986 |
| Marlborough Group Holdings Limited | Financial services | 2016 |
| Marlborough Investment Management Limited | Financial services | 1985 |
| Marlborough Investment Management(Uk)Limited | Professional & scientific | 1986 |
| Marlborough Nominee Limited | Financial services | 2017 |
| Marlborough Partnership Limited | Other services | 2024 |
| Marlborough Unit Trust Managers Limited | Professional & scientific | 2001 |
| Marlin Associates Limited | Other services | 2018 |
| Marlwood Developments Limited | Construction | 2018 |
| Marmalade Club Ltd | Hospitality | 2026 |
| Marmalade Solutions Ltd | Professional & scientific | 2025 |
| Marmaris Food (Bolton) Ltd | Hospitality | 2020 |
| Marnish Ltd | Wholesale & retail | 2021 |
| Marnland Commercial Ltd | Real estate | 2019 |
| Marothi Estates Ltd | Real estate | 2023 |
| Marrick Property Investments Limited | Real estate | 2021 |
| Marrow Group Limited | Hospitality | 2025 |
| Mars Medical Aesthetics Ltd | Health & social care | 2025 |
| Marsden Inns Limited | Hospitality | 1994 |
| Marsh Fold Residents Management Company Limited | Households | 2025 |
| Marsi Suppliers Ltd | Wholesale & retail | 2013 |
| Marsland Retail Ltd | Wholesale & retail | 2017 |
| Marston Developments North West Limited | Construction | 2021 |
| Mart Property Limited | Financial services | 2026 |
| Martel Performance Ltd | Education | 2023 |
| Martforbrands Ltd | Wholesale & retail | 2025 |
| Martin O'Connor & Associates Ltd | Health & social care | 2010 |
| Martindale Asset Management Ltd | Real estate | 2026 |
| Martindales Holdings Limited | Financial services | 2026 |
| Martindales Limited | Construction | 1993 |
| Martindales Property Holdings Limited | Financial services | 2026 |
| Martins Mews Management RTM Company Ltd | Households | 2023 |
| Martshire Ltd | Wholesale & retail | 2021 |
| Martyn Salt Limited | Professional & scientific | 2018 |
| Marval Driving Limited | Transport & logistics | 2014 |
| Marx Walks Ltd | Education | 2025 |
| Mary J Beauty Hair Salon Limited | Other services | 2019 |
| Maryam's Yummies Ltd | Hospitality | 2018 |
| Maryjane Cares Ltd | Health & social care | 2025 |
| Maryson Limited | Wholesale & retail | 2020 |
| Marz Productions Limited | Information & communication | 2025 |
| Marz Properties Limited | Real estate | 2016 |
| MAS Foods Limited | Hospitality | 2025 |
| Masalaa Bites Ltd | Manufacturing | 2025 |
| Mash's Bolton Ltd | Hospitality | 2024 |
| Mash's Wing Ranch Limited | Hospitality | 2012 |
| MASHRO3AT.COM Limited | Extraterritorial | 2021 |
| Masia Builders Ltd | Construction | 2019 |
| Masibell Limited | Professional & scientific | 2002 |
| Mask Traders Ltd | Wholesale & retail | 2023 |
| Mason Consulting & Project Management Ltd | Professional & scientific | 2025 |
| Mason Grace Investments Limited | Real estate | 2016 |
| Mason Grace Limited | Real estate | 2022 |
| Mason Tustin Personal Training Ltd | Education | 2025 |
| Masonjay Ltd | Wholesale & retail | 2024 |
| Massa Transport Limited | Transport & logistics | 2026 |
| Massey Property Maintenance & Management Ltd | Construction | 2005 |
| Massey Sports Limited | | 1974 |
| Masseyacademy Ltd | Education | 2025 |
| Master Brickwork Limited | Real estate | 2004 |
| Master Enterprise (Bolton) Ltd | Real estate | 2022 |
| Master Halal Butcher Limited | Wholesale & retail | 2021 |
| Master Pipe International Ltd | Wholesale & retail | 2019 |
| Master Property Maintenance Service Ltd | Construction | 2019 |
| Master Ruaf Repairing Ltd | Administrative & support | 2024 |
| Master Windows and Doors Ltd | Construction | 2024 |
| Masters Joinery Consulting Ltd | Manufacturing | 2026 |
| Mastertint UK Limited | Wholesale & retail | 2018 |
| Mastery Consultancy Limited | Professional & scientific | 2025 |
| Masventas Limited | Professional & scientific | 2023 |
| Matadar Holdings Limited | Financial services | 2023 |
| Matadar Investments 01 Limited | Real estate | 2026 |