| Made on Earth Limited | Wholesale & retail | 2011 |
| Made Together Ltd | Professional & scientific | 2013 |
| Made.Com Design Ltd | Wholesale & retail | 2009 |
| Madeby.Studio Ltd | Professional & scientific | 2019 |
| Madebypi Digital Limited | Information & communication | 2019 |
| Madeeasymarketing Limited | Information & communication | 2025 |
| Madeley Enterprises Limited | Administrative & support | 2006 |
| Mademoiselleharrison Ltd | Real estate | 2021 |
| Madex Logistics Ltd | Transport & logistics | 2002 |
| Madfran Ltd | Health & social care | 2013 |
| Madiba Group Ltd | Financial services | 2022 |
| Madiba Holdings Ltd | Financial services | 2024 |
| Madiba Homes Limited | Real estate | 2022 |
| Madiba Limited | Health & social care | 2019 |
| Madiba Properties Ltd | Real estate | 2022 |
| Madiba Yorkshire Limited | Households | 2022 |
| Madicon Ltd | Health & social care | 2017 |
| Madina Food Leeds Ltd | Wholesale & retail | 2025 |
| Madina Pizza UK Ltd | Hospitality | 2025 |
| Madina Stays Limited | Real estate | 2025 |
| Madina Takeaway Ltd | Hospitality | 2020 |
| Madina Tayibah Properties Limited | Real estate | 2026 |
| Madison Hosiery Limited | Wholesale & retail | 1994 |
| Madison Investments Ltd | Real estate | 2019 |
| Madison Offices Ltd | Real estate | 2020 |
| Madisons Fitness Ltd | Arts & recreation | 2021 |
| Madoc and Rhodes (LEA Village) Limited | Financial services | 1996 |
| Madorsa Ltd | Other services | 2024 |
| Madrilengua Limited | Professional & scientific | 2014 |
| Mads and Charley Ltd | Construction | 2022 |
| Maduma Limited | Health & social care | 2022 |
| Mady Delivery Ltd | Transport & logistics | 2025 |
| MAE and Mitchell Bespoke Management Community Interest Company | Health & social care | 2019 |
| MAE Assets Ltd | Real estate | 2024 |
| MAE Office Limited | Real estate | 2025 |
| MAE Self Defence and Fitness Ltd | Arts & recreation | 2021 |
| Maebel & Co Ltd | Real estate | 2025 |
| Maec Capital Ltd | Financial services | 2025 |
| Maelstrom Management Company Limited | Households | 2005 |
| Maes Handmade Ltd | Wholesale & retail | 2019 |
| MAF Consultancy Limited | Professional & scientific | 2023 |
| Mafwa Theatre CIC | Administrative & support | 2019 |
| MAG Contract and Commercial Solutions Ltd | Construction | 2021 |
| MAG Merchants Limited | Wholesale & retail | 2025 |
| MAG Northern Limited | Real estate | 2016 |
| Mag-Nkosi Care Limited | Health & social care | 2014 |
| Magdala Management Co. Limited | Households | 1983 |
| Magdalacare Ltd | Health & social care | 2025 |
| Magdalenka Polish Mini Market Ltd | Hospitality | 2010 |
| Magee Holdings (Yorkshire) Ltd | Real estate | 2022 |
| Magellan Advisory Partners Limited | Professional & scientific | 2019 |
| Magenta Services Ltd | Construction | 2025 |
| Maggie Contractors Ltd | Construction | 2017 |
| Maggies Tea Rooms (Leeds) Ltd | Hospitality | 2026 |
| Magha Holdings Ltd | Wholesale & retail | 2026 |
| Magic Flash Ltd | Administrative & support | 2025 |
| Magic HCC Ltd | Manufacturing | 2024 |
| Magic Ironing and Laundry Ltd | Other services | 2023 |
| Magic Space Dust Ltd | Information & communication | 2021 |
| Magic Touch Cleaning Service Leeds Ltd | Administrative & support | 2020 |
| Magical North Productions Limited | Information & communication | 2023 |
| Magis Group Limited | Administrative & support | 2025 |
| Magna Accounting Limited | Professional & scientific | 2022 |
| Magna Carta Group Limited | Wholesale & retail | 2020 |
| Magna Flex Limited | Professional & scientific | 2024 |
| Magna Group Holdings Limited | Financial services | 2023 |
| Magna Outsourcing Limited | Administrative & support | 2021 |
| Magnet Express Limited | Other services | 2008 |
| Magnifique Lifestyle Ltd | Wholesale & retail | 2019 |
| Magnimo Limited | Information & communication | 2013 |
| Magnolia JV Limited | Wholesale & retail | 2026 |
| Magnum Opus Investments Ltd | Financial services | 2016 |
| Magnum Pro Limited | Health & social care | 2021 |
| Magnum Security Solutions Limited | Other services | 2025 |
| Magnum Thesaurus Distribution Ltd | Transport & logistics | 2025 |
| Magnus Optus Ltd | Wholesale & retail | 2024 |
| Magolde Ltd | Public administration | 2025 |
| Magpi Ltd | Real estate | 2020 |
| Magpie Creative Communications Limited | Professional & scientific | 2011 |
| Magpie Signature Smiles Ltd | Health & social care | 2025 |
| Magpie Talent Agency Ltd | Other services | 2025 |
| Magpie Teaching Company Ltd | Education | 2025 |
| Magrathea Research Ltd | Professional & scientific | 2021 |
| Maguire Cervantes Property Limited | Real estate | 2021 |
| Magveris Ltd | Information & communication | 2024 |
| Magwarren Limited | Professional & scientific | 2014 |
| Magwest Properties Limited | Real estate | 2018 |
| Magyar Enterprises Limited | Real estate | 2019 |
| MAH Electronics Ltd | Wholesale & retail | 2026 |
| MAH Engineering Limited | Professional & scientific | 2017 |
| Maha Lakshmi IT Services Ltd | Information & communication | 2025 |
| Maha Lakshmi Ltd | Real estate | 2021 |
| Mahabad Ltd | Wholesale & retail | 2020 |
| Mahadev Properties Ltd | Real estate | 2024 |
| Mahajan Estates Limited | Real estate | 2022 |
| Maharshi and Daughters Ltd | Real estate | 2021 |
| Mahdieh Ltd | Administrative & support | 2023 |
| Mahdlo Investments Limited | Real estate | 1942 |
| Mahendra Consultancy Ltd | Health & social care | 2018 |
| Maher Accountancy Services Limited | Professional & scientific | 2003 |