| MAC Metals Limited | Manufacturing | 2021 |
| MAC Pave and Landscapes Limited | Administrative & support | 2018 |
| MAC Plumbing and Heating Solutions Ltd | Construction | 2024 |
| MAC Tech Limited | Wholesale & retail | 2024 |
| Macb Trading Ltd | Wholesale & retail | 2020 |
| Macclesfield Denture Clinic Ltd | Health & social care | 2012 |
| Maccplas Limited | Wholesale & retail | 2006 |
| Macfarlane Holdings (UK) Limited | Administrative & support | 2021 |
| Macfarlane Investment Holdings Limited | Financial services | 2025 |
| Mach-Aire (Holdings) Limited | Professional & scientific | 2019 |
| Machick Ltd | Hospitality | 2018 |
| Machina Labs Limited | Information & communication | 2022 |
| Machine Tool Supplies Limited | Wholesale & retail | 1991 |
| Machos Bolton Ltd | Hospitality | 2025 |
| Machos Ltd | Hospitality | 2021 |
| Machos Piri Piri Limited | Hospitality | 2025 |
| Macinnes Ltd | Professional & scientific | 2017 |
| Macmarshalls Ltd | Professional & scientific | 2019 |
| Macrofact Limited | Professional & scientific | 1999 |
| MACS4 Ltd | Wholesale & retail | 2016 |
| Macula Design Ltd | Professional & scientific | 2023 |
| Macxtech Ltd | Information & communication | 2023 |
| MAD Bull Events Limited | Arts & recreation | 2015 |
| MAD Designers Ltd | Wholesale & retail | 2025 |
| MAD Investment Solutions Limited | Real estate | 2022 |
| MAD Jack Limited | Hospitality | 2025 |
| Madam Properties Limited | Real estate | 2023 |
| Madam's Goods Limited | Wholesale & retail | 2015 |
| Madani 786 Properties Ltd | Real estate | 2026 |
| Madani Food Farnworth Ltd | Wholesale & retail | 2017 |
| Madani Real Estate Limited | Real estate | 2020 |
| Madani Solutions Limited | Information & communication | 2009 |
| Madany Limited | Health & social care | 2023 |
| Maddox JAX Ltd | Real estate | 2020 |
| Made by Biscuits Ltd | Information & communication | 2025 |
| Made to Order Marketing Recipes Limited | Professional & scientific | 2025 |
| Made UP Name Promotions Limited | Arts & recreation | 2016 |
| Madecroft & Co Limited | Professional & scientific | 2026 |
| Madeitmehndi Limited | Health & social care | 2024 |
| Madgalena Wolinska Ltd | Health & social care | 2013 |
| Madgetastic Ltd | Health & social care | 2023 |
| Madhu Shankar Ltd | Health & social care | 2018 |
| Madhusudhana Solutions Limited | Hospitality | 2018 |
| Madibra Nest Ltd | Real estate | 2025 |
| Madina Box Centre Limited | Wholesale & retail | 2018 |
| Madina Housing Ltd | Real estate | 2025 |
| Madina Investments Limited | Financial services | 2023 |
| Madina Jewellers (North West) UK Limited | Wholesale & retail | 2016 |
| Madina Jewellers Limited | Wholesale & retail | 2006 |
| Madina Properties NW Limited | Real estate | 2023 |
| Madina SS Holdings Ltd | Financial services | 2025 |
| Madiox Limited | Hospitality | 2021 |
| Madisons Ltd | Real estate | 2016 |
| Madj Investments Limited | Construction | 2020 |
| Madni Capitals Ltd | Health & social care | 2026 |
| Madzk Ltd | Wholesale & retail | 2026 |
| Maerfield Medical Ltd | Health & social care | 2021 |
| Mafa Services Ltd | Professional & scientific | 2020 |
| Magadi Paulo Support Worker Ltd | Health & social care | 2016 |
| Magda Lenna Limited | Information & communication | 2023 |
| Magee,Marshall and Company,Limited | Manufacturing | 1888 |
| Magic Fabric UK Ltd | Wholesale & retail | 2022 |
| Magic Gate Ltd | Administrative & support | 2025 |
| Magic Ingredients Consultancy Limited | Information & communication | 2023 |
| Magic Nails 86 Ltd | Other services | 2026 |
| Magic Well Labs Ltd | Wholesale & retail | 2026 |
| Magic Years Limited | Administrative & support | 2021 |
| Magic Zebra Limited | Information & communication | 2026 |
| MAGIC4STORES Ltd | Manufacturing | 2023 |
| MAGIC7 Limited | Information & communication | 2012 |
| Magickitchens Manchester Ltd | Manufacturing | 2011 |
| Magna Certus Limited | Real estate | 2023 |
| Magnaline Systems Ltd | Manufacturing | 2013 |
| Magnate London Ltd | Wholesale & retail | 2024 |
| Magnate Properties Ltd | Real estate | 2020 |
| Magnetise UK Limited | Wholesale & retail | 2024 |
| Magneto Tools Limited | Wholesale & retail | 2019 |
| Magnitudo Ltd | Other services | 2017 |
| Magnolias JPR Limited | Information & communication | 2008 |
| Magnum Epos Ltd | Information & communication | 2016 |
| Magnum Smart Ride Private Hire Limited | Transport & logistics | 2018 |
| Magsons Apart Hotel (UK) Ltd | Hospitality | 2013 |
| Magsons International Limited | Hospitality | 2021 |
| Magtech Solutions Limited | Information & communication | 2019 |
| Mahal Discount Stores Ltd | Wholesale & retail | 2025 |
| Mahan Holdings Ltd | Real estate | 2020 |
| Mahdi Properties & Construction Limited | Real estate | 2019 |
| Mahek Limited | Professional & scientific | 2004 |
| Maher Tiling Contractors Limited | Construction | 2012 |
| Mahmood Holdings Limited | Construction | 2015 |
| Mahq Ltd | Information & communication | 2022 |
| Mahum Pharma Ltd | Health & social care | 2015 |
| Maida Money Ltd | Other services | 2019 |
| Maik Medical Services Limited | Health & social care | 2012 |
| Maine Consulting Limited | Professional & scientific | 2024 |
| Maini Dentalcare Limited | Health & social care | 2011 |
| Mainland Catering Equipment Limited | Wholesale & retail | 1997 |
| Mainland Refurbishment Limited | Wholesale & retail | 2011 |
| Mainline Private Hire Limited | Transport & logistics | 1988 |
| Maisarch Property Ltd | Real estate | 2024 |