| MA5 Car Traders Ltd | Wholesale & retail | 2024 |
| MAA Selby Ltd | Hospitality | 2023 |
| MAA Travel Ltd | Wholesale & retail | 2023 |
| MAA07 Consulting Ltd | Professional & scientific | 2025 |
| Maab Trading Company Limited | Wholesale & retail | 2020 |
| Maad Works Ltd | Information & communication | 2018 |
| Maake Academy Ltd | Professional & scientific | 2022 |
| Maali Group Limited | Education | 2022 |
| Maalqabo Ltd | Transport & logistics | 2026 |
| Maana Company Ltd | Health & social care | 2013 |
| Maaytah Investments Ltd | Real estate | 2025 |
| MAB Computers Ltd | Information & communication | 2024 |
| MAB Joinery Limited | Construction | 2013 |
| MAB Trading Limited | Wholesale & retail | 2018 |
| MAB786 Ltd | Real estate | 2026 |
| Maba Koli Community Leeds Ltd | Health & social care | 2023 |
| Mabanes Properties Limited | Real estate | 1927 |
| Mabbott Design Limited | Administrative & support | 2014 |
| Mabbs Logistics Ltd | Transport & logistics | 2018 |
| Mabgate Facilities Management Limited | Real estate | 2024 |
| Mabgate Gateway (Management) Ltd | Real estate | 2018 |
| Mabgate Motors (Leeds) Ltd | Wholesale & retail | 2018 |
| Mabi Music Ltd | Arts & recreation | 2026 |
| Mabury Ltd | Real estate | 2020 |
| MAC Enviro Systems Ltd | Construction | 2021 |
| MAC Media (Leeds) Limited | Professional & scientific | 2012 |
| MAC Productions (Sound & Lighting) Limited | Arts & recreation | 2014 |
| MAC Repair Leeds Limited | Manufacturing | 2012 |
| MAC Repair Ltd | Other services | 2010 |
| MAC Repair Nottingham Limited | Information & communication | 2014 |
| MAC Vodka Limited | Wholesale & retail | 2020 |
| MAC2 Leeds Limited | Construction | 2023 |
| Macaw Markets Limited | Wholesale & retail | 2025 |
| Macca Syndicate Ltd | Transport & logistics | 2026 |
| Macchiato Lounge Ltd | Hospitality | 2025 |
| Maccomms (Yorkshire) Ltd | Administrative & support | 2015 |
| Macdonald Holdings Limited | Real estate | 2016 |
| Macdonald Old England Limited | Hospitality | 2006 |
| Macdui Bidco Limited | Financial services | 2025 |
| Macdui Topco Limited | Financial services | 2025 |
| Mace Civil Engineering Ltd | Construction | 2020 |
| Mace Electrical Ltd | Construction | 2023 |
| Mace Store Limited | Wholesale & retail | 2006 |
| Maces Places Limited | Real estate | 2025 |
| Macess Properties Limited | Real estate | 1977 |
| Macey Janes Limited | Other services | 2025 |
| Macgold Direct Limited | Wholesale & retail | 1995 |
| Mach Recruitment Limited | Administrative & support | 2007 |
| MACH5 Group Ltd | Administrative & support | 2024 |
| Machaka Motors Limited | Transport & logistics | 2017 |
| Machell Brothers Holdings Limited | Financial services | 2020 |
| Machell Brothers,Limited | Real estate | 1895 |
| Machinery Maintenance Services Ltd | Manufacturing | 2018 |
| Mackenzie Hall Investments Ltd | Real estate | 2019 |
| Mackenzie Stuart Executive Search Limited | Administrative & support | 2018 |
| Mackenzie Stuart Group Holdings Limited | Extraterritorial | 2019 |
| Mackinnon Bruce Chemicals & Consumer Limited | Administrative & support | 2021 |
| Mackinnon Bruce Group Holdings Limited | Administrative & support | 2021 |
| Mackinnon Bruce Heavy Industry & Construction Limited | Administrative & support | 2021 |
| Mackinnon Bruce Industrial & Life Sciences Limited | Administrative & support | 2021 |
| Mackinnon Bruce Limited | Administrative & support | 2012 |
| Mackinnon Bruce Sustainable Futures Limited | Administrative & support | 2022 |
| Maclaren Windows Ltd | Construction | 2024 |
| Maclunga Investments Limited | Wholesale & retail | 2025 |
| Macmack Ltd | Professional & scientific | 2023 |
| Macmar Cater Limited | Hospitality | 2018 |
| Macmed Ltd | Health & social care | 2018 |
| Maco Cleaning Company Limited | Administrative & support | 2007 |
| Macovei SPT Ltd | Construction | 2023 |
| Macpower Limited | Wholesale & retail | 2018 |
| Macrolarge International Ltd | Professional & scientific | 2020 |
| Macrovend Ltd | Wholesale & retail | 2026 |
| Macroya Investments (UK) Limited | Wholesale & retail | 2023 |
| Macs Property Limited | Real estate | 2019 |
| MAD Business Limited | Professional & scientific | 2024 |
| MAD Frans Bar Ltd | Hospitality | 2019 |
| MAD Goose Games Limited | Arts & recreation | 2026 |
| MAD Monkey Labs Ltd | Health & social care | 2023 |
| MAD Product Ltd | Wholesale & retail | 2020 |
| MAD42MORROW Ltd | Other services | 2011 |
| MAD4MINI Limited | Wholesale & retail | 2009 |
| MAD4MINI Motorsport Limited | Wholesale & retail | 2018 |
| Mada Properties (England) Ltd | Real estate | 2023 |
| Madalin Florin Patoi Ltd | Transport & logistics | 2025 |
| Madalintech Dynamics Ltd | Transport & logistics | 2018 |
| Madalitso KAY Limited | Public administration | 2024 |
| Madanatco Ltd | Health & social care | 2020 |
| Madd Limited | Professional & scientific | 2007 |
| Madden Property Investments Ltd | Real estate | 2024 |
| Maddie's Photography Ltd | Professional & scientific | 2025 |
| Maddiebody Ltd | Arts & recreation | 2023 |
| Maddietagg Ltd | Professional & scientific | 2025 |
| Maddison Business Services Ltd | Information & communication | 2016 |
| Maddison Lettings Limited | Real estate | 2020 |
| Maddison Residence Holdings Limited | Construction | 2022 |
| Maddog Retail Ltd | Wholesale & retail | 2018 |
| Made 4 UK (Homes) Limited | Construction | 2017 |
| Made by Bridge Limited | Information & communication | 2012 |
| Made Easy Education Ltd | Education | 2014 |
| Made in Yorkshire Homes Limited | Real estate | 2021 |