| Magic Key Ltd | Wholesale & retail | 2021 |
| Magic Mirage Corp Limited | Information & communication | 2024 |
| Magic Sourcing Limited | Wholesale & retail | 2023 |
| Magic Sprout Education Ltd | Education | 2024 |
| Magic World B&G Ltd | Wholesale & retail | 2021 |
| Magical Celebrations Limited | Hospitality | 2023 |
| Magical Emporium Limited | Wholesale & retail | 2018 |
| Magical International Limited | Professional & scientific | 2007 |
| Magical Manifestation Ltd | Professional & scientific | 2025 |
| Magical Systems Limited | Professional & scientific | 2018 |
| Magicfirst Limited | Real estate | 2000 |
| Magicgrill Limited | Hospitality | 2025 |
| Magicmunchkin Ltd | Transport & logistics | 2019 |
| Magiconstructions Ltd | Construction | 2019 |
| Magicool Limited | Wholesale & retail | 2021 |
| Magindustries Ltd | Manufacturing | 2018 |
| Maginserts Ltd | Wholesale & retail | 2025 |
| Magna Mundo Limited | Wholesale & retail | 2025 |
| Magna Suite Limited | Wholesale & retail | 2020 |
| Magna Trading Limited | Administrative & support | 2007 |
| Magna Vita Group Limited | Financial services | 2024 |
| Magnet Media World Ltd | Information & communication | 2019 |
| Magnetic Gym BAG Ltd | Manufacturing | 2025 |
| Magnificent Macarons Ltd | Manufacturing | 2019 |
| Magnify Tech Ltd | Information & communication | 2022 |
| Magnitude Consulting Ltd | Information & communication | 2020 |
| Magnitude Electrical's Ltd | Construction | 2018 |
| Magno Fibers UK Ltd | Wholesale & retail | 2022 |
| Magnolia Freehold Limited | Households | 2023 |
| Magnolia IH Ltd | Real estate | 2020 |
| Magnum Beauty International Limited | Wholesale & retail | 2015 |
| Magnus Project Planning Limited | Professional & scientific | 2013 |
| Magor Services Limited | Wholesale & retail | 2014 |
| Magowie Ltd | Information & communication | 2025 |
| Magpie Concept Ltd | Information & communication | 2020 |
| Magpie Projects & Development Limited | Construction | 2026 |
| Magpie Security (NE) Limited | Administrative & support | 2016 |
| Magrum Services Limited | Construction | 2009 |
| Maguire Consulting Ltd | Professional & scientific | 2021 |
| MAH Food Cort Ltd | Hospitality | 2020 |
| MAH! Brands Limited | Manufacturing | 2012 |
| Maha Al-Ain for Trading and Contracting Ltd | Wholesale & retail | 2024 |
| Mahabharata Productions Limited | Information & communication | 2010 |
| Mahad & Fahad Limited | Health & social care | 2015 |
| Mahadev Logistics Limited | Administrative & support | 2024 |
| Mahal Glazing Ltd | Manufacturing | 2019 |
| Maham Altaf Ltd | Wholesale & retail | 2025 |
| Mahar Wikton Shop Ltd | Wholesale & retail | 2025 |
| Mahashambhu Ltd | Health & social care | 2025 |
| Maher Electronic Academy Ltd | Education | 2024 |
| Mahes Properties Limited | Real estate | 2024 |
| Mahes Stores Ltd | Wholesale & retail | 2026 |
| Mahesh Aqua International Limited | Wholesale & retail | 2022 |
| Mahex Limited | Transport & logistics | 2014 |
| Mahey Developments Limited | Real estate | 2021 |
| Maheyli | Professional & scientific | 2023 |
| Mahi's Kitchen Ltd | Hospitality | 2023 |
| Mahindra PVT Ltd | Wholesale & retail | 2023 |
| Mahjabeen UK Limited | Professional & scientific | 2025 |
| Mahmoud Gamal for Wholesale and Retail Trade Ltd | Wholesale & retail | 2025 |
| Mahmoud Omar Ltd | Wholesale & retail | 2024 |
| Mahmoud Samy Ltd | Wholesale & retail | 2025 |
| Mahmud Budtjenester Limited | Extraterritorial | 2025 |
| Mahota Investments Ltd | Financial services | 2020 |
| Mahra.Io Ltd | Administrative & support | 2024 |
| Mahrokh Moghbel Limited | Health & social care | 2018 |
| Mahrousa Excellence Business Limited | Wholesale & retail | 2025 |
| Mahsa Limited | Real estate | 2007 |
| MAI DUN Consultancy Services Ltd | Information & communication | 2019 |
| MAI FRY Property Limited | Real estate | 2014 |
| MAI OH MAI Ltd | Arts & recreation | 2014 |
| MAI Semipermanent Make UP Ltd | Other services | 2024 |
| Maia Expansions Ltd | Information & communication | 2025 |
| Maiacombo Ltd | Wholesale & retail | 2022 |
| Maid Digital Limited | Administrative & support | 2019 |
| MAID2CLEAN (Salisbury & Trowbridge) Ltd | Administrative & support | 2013 |
| MAID2CLEAN (South Lincs) Ltd | Administrative & support | 2024 |
| MAID2CLEAN (Tonbridge) Limited | Households | 2016 |
| MAID2CLEAN North Manchester Ltd | Administrative & support | 2026 |
| MAID2CLEAN Shine Ltd | Administrative & support | 2026 |
| MAID2CLEAN Worthing Limited | Administrative & support | 2018 |
| Maidsfield Group Limited | Professional & scientific | 1978 |
| Maijexport LLP | | 2015 |
| Main Real Services Limited | Information & communication | 2019 |
| Main Tenants Team Limited | Households | 2023 |
| Main-Line Access Ltd | Construction | 2025 |
| Mainchord Group Ltd | Information & communication | 2019 |
| Maindy Estates Limited | Real estate | 1953 |
| Maindy Management Limited | Real estate | 2015 |
| Maine Inspection Ltd | Professional & scientific | 2007 |
| Maine-Stream Limited | Professional & scientific | 2005 |
| Mainey's Property Maintenance Ltd | Construction | 2020 |
| Mainmate Builders Limited | | 1978 |
| Mainswell & Group Limited | Information & communication | 2025 |
| Maintain IT ALL Limited | Construction | 2024 |
| Maintain IT ALL Properties Limited | Real estate | 2025 |
| Maintain Services Ltd | Other services | 2019 |
| Maintain-Ants Limited | Administrative & support | 2020 |
| Maintaindirect.Com SW Ltd | Construction | 2024 |
| Maintenance Free Limited | Construction | 2004 |