| Magmaworks Ltd | Information & communication | 2021 |
| Magna Property Management Ltd | Real estate | 2020 |
| Magna Surfacing Limited | Construction | 2019 |
| Magnatec International Limited | Manufacturing | 2001 |
| Magnet Developments Limited | Real estate | 2020 |
| Magnet Pubs and Bars Ltd | Hospitality | 2016 |
| Magnetic North Ltd | Information & communication | 2026 |
| Magnifique YOU Limited | Other services | 2015 |
| Magnohard Limited | Professional & scientific | 1981 |
| Magnolia Living Ltd | Real estate | 2025 |
| Magnum Opus Broadcasting Limited | Information & communication | 2003 |
| Magnum Traders Ltd | Wholesale & retail | 2025 |
| Magnus Contemporary Catering Ltd | Hospitality | 2011 |
| Magowan Property Group Limited | Real estate | 2022 |
| Magpay Limited | Administrative & support | 2024 |
| Magpie Legal Services Limited | Administrative & support | 2017 |
| Mags Plastering & Fire Protection Limited | Construction | 2025 |
| Mags Property Ltd | Real estate | 2021 |
| Magurk IT Limited | Information & communication | 2016 |
| MAH Locums Ltd | Health & social care | 2024 |
| Maha Solutions Ltd | Administrative & support | 2018 |
| Mahabbatun-Nuur Tijaniyyah Centre Limited | Education | 2026 |
| Mahajan Properties Ltd | Real estate | 2018 |
| Mahan Estates Ltd | Real estate | 2026 |
| Mahdi Liverpool Ltd | Wholesale & retail | 2022 |
| Maher Digital Services Ltd | Information & communication | 2026 |
| Mahesti Ltd | Wholesale & retail | 2022 |
| Mahhe Store Ltd | Wholesale & retail | 2025 |
| Mahoe Blue Bistro and Catering Ltd | Hospitality | 2025 |
| Mahoney Investments Limited | Real estate | 2010 |
| Mahr Properties Limited | Real estate | 2025 |
| Mahred Ltd | Information & communication | 2019 |
| Mahtal Group Ltd | Information & communication | 2024 |
| MAI Thai Cuisine Ltd | Hospitality | 2025 |
| Maia (US) Limited | Financial services | 2021 |
| Maia Investments Limited | Financial services | 2022 |
| Maia Rapkin Consultancy Ltd | Professional & scientific | 2014 |
| Maia+ Limited | Financial services | 2019 |
| Maid Right Cleaning Ltd | Administrative & support | 2022 |
| Maid Right Domestic Cleaning Ltd | Administrative & support | 2024 |
| MAID2CLEAN (Preston) Ltd | Administrative & support | 2016 |
| MAID2CLEAN Lancaster and Chorley Ltd | Administrative & support | 2017 |
| Maiden Holdings Limited | Financial services | 2023 |
| Maiden Management Limited | Professional & scientific | 2023 |
| Mailbakes Ltd | Hospitality | 2024 |
| Maili Trading Company Ltd | Wholesale & retail | 2022 |
| Mails and Sales Ltd | Information & communication | 2024 |
| Main Drywall Limited | Construction | 2016 |
| Main Insulations Limited | Construction | 2014 |
| Main Interiors Ltd | Construction | 2022 |
| Main RUM Company Limited(The) | Wholesale & retail | 1984 |
| Mainaaccess Ltd | Construction | 2026 |
| Mainar Limited | Hospitality | 2019 |
| Mainey & Associates Wealth Management Limited | Financial services | 2023 |
| Maingrant Limited | Education | 2005 |
| Mainjoy Limited | Extraterritorial | 1985 |
| Mainline Paving and Civils Limited | Construction | 2024 |
| Mainsail Haulage Limited | Transport & logistics | 1994 |
| Mainside Properties Ltd | Real estate | 2020 |
| Mainsprint Limited | Mining & quarrying | 1983 |
| Maintenance & Installation Services Limited | Administrative & support | 2022 |
| Maintenance Free Roofing Ltd | Construction | 2019 |
| Mairinjess Limited | Health & social care | 2016 |
| Mairiss Ltd | Information & communication | 2025 |
| Maisey Barrett Ltd | Public administration | 2025 |
| Maisiemoo Properties Limited | Real estate | 2024 |
| Maison Benistan Ltd | Manufacturing | 2024 |
| Maison Chahinaz Limited | Hospitality | 2024 |
| Maison Inti Limited | Wholesale & retail | 2026 |
| Maison Merseyside Limited | Real estate | 2014 |
| Maison the Dreams Ltd | Households | 2025 |
| Maison Voyage DE Luxe Limited | Hospitality | 2025 |
| Maisonsducharme Ltd Ltd | Real estate | 2025 |
| Maitland House Builders Ltd | Construction | 2025 |
| Maitri Liverpool Limited | Health & social care | 2020 |
| Mai’S Nail Bar Ltd | Other services | 2025 |
| MAJ Develope Ltd | Construction | 2025 |
| MAJ Joinery Ltd | Construction | 2019 |
| MAJ Property Holdings Ltd | Real estate | 2023 |
| Maja Lease Company Limited | Real estate | 2015 |
| Maja's Cleaning Ltd | Construction | 2020 |
| MAJA13 Transport Ltd | Transport & logistics | 2019 |
| Majestic Design Solutions Ltd | Professional & scientific | 2023 |
| Majestic Engineering Limited | Manufacturing | 1984 |
| Majestic Properties (NW) Ltd | Real estate | 2019 |
| MAJID1964 Limited | Hospitality | 2014 |
| Major Haulage Ltd | Wholesale & retail | 2025 |
| Major Red Properties Ltd | Real estate | 2022 |
| Major Ventures Trading Limited | Wholesale & retail | 2018 |
| MAK Commercial Solutions Ltd | Wholesale & retail | 2023 |
| Makaldar Limited | Other services | 1966 |
| Makana Leadership Limited | Professional & scientific | 2020 |
| Make a Deal Limited | Wholesale & retail | 2020 |
| Make a Difference Marketing Limited | Professional & scientific | 2018 |
| Make HAY Design Ltd | Information & communication | 2022 |
| Make IT Human Limited | Administrative & support | 2024 |
| Make Life Kind Trust | Education | 2022 |
| Make ME Pretty Ltd | Other services | 2022 |
| Make Mouth Music CIC | Education | 2025 |
| Make Records CIC | Information & communication | 2025 |