| MAB Suites CW IV Limited | Real estate | 2022 |
| MAB Suites CW IX Limited | Real estate | 2022 |
| MAB Suites CW VI Limited | Real estate | 2022 |
| MAB Suites CW VII Limited | Real estate | 2022 |
| MAB Suites CW X Limited | Real estate | 2022 |
| MAB Suites CW XI Limited | Real estate | 2022 |
| MAB Suites CW XII Limited | Real estate | 2023 |
| MAB Suites CW Xiii Limited | Real estate | 2023 |
| MAB Suites Limited | Real estate | 2019 |
| MAB Suites Liverpool I Limited | Real estate | 2022 |
| MAB Suites Liverpool II Limited | Real estate | 2023 |
| MAB Suites Reading II Limited | Real estate | 2021 |
| MAB Suites Reading VII Limited | Real estate | 2022 |
| Mabel Care Limited Limited | Health & social care | 2019 |
| Mabel Home Ltd | Wholesale & retail | 2018 |
| Mabel's Crafts Limited | Extraterritorial | 2015 |
| Mable Digital Ltd | Information & communication | 2021 |
| Mabt Skin Ltd | Other services | 2020 |
| MAC & Co Properties Ltd | Real estate | 2023 |
| MAC & Co Services Ltd | Health & social care | 2018 |
| MAC 10 Energy Ltd | Administrative & support | 2025 |
| MAC Attachments Ltd | Manufacturing | 2024 |
| MAC Autobody Ltd | Wholesale & retail | 2021 |
| MAC Electrical NW Ltd | Construction | 2025 |
| MAC Energy Solutions Ltd | Construction | 2020 |
| MAC Environmental Services Limited | Other services | 2003 |
| MAC Five Real Estate Ltd | Real estate | 2024 |
| MAC Glazing (NW) Ltd | Construction | 2022 |
| MAC Home Properties Limited | Construction | 2024 |
| MAC Logistics (Liverpool) Ltd | Transport & logistics | 2025 |
| MAC Logistics Limited | Transport & logistics | 2004 |
| MAC Management Services Limited | Real estate | 2015 |
| MAC Portfolio Limited | Administrative & support | 2021 |
| MAC Trading NW Ltd | Hospitality | 2017 |
| MAC Training Ltd | Education | 2019 |
| MAC Ventilation Services Limited | Construction | 2019 |
| MAC25 Limited | Financial services | 2024 |
| MAC26 Limited | Financial services | 2024 |
| MAC27 Limited | Financial services | 2024 |
| MAC28 Limited | Financial services | 2024 |
| MAC6 Limited | Health & social care | 2015 |
| Mace Maritime Consultancy Service Ltd | Professional & scientific | 2015 |
| MACELLO2 Meathouse Ltd | Hospitality | 2020 |
| Macgeo Limited | Extraterritorial | 2025 |
| Machermore Castle Ltd | Other services | 2019 |
| Machermore Lodges Ltd | Hospitality | 2024 |
| Machine Brokers Limited | Wholesale & retail | 2021 |
| Machines 4 YOU Ltd | Wholesale & retail | 2024 |
| Machmade Limited | Construction | 1987 |
| Machory Fashion Limited | Wholesale & retail | 2016 |
| Macinnes Software Solutions Limited | Information & communication | 2013 |
| Maciver Marketing Ltd | Professional & scientific | 2025 |
| Mack Sports Consultancy Ltd | Arts & recreation | 2021 |
| Mackay & Simpson Fencing Limited | Construction | 2009 |
| Mackay & Simpson Holdings Limited | Financial services | 2018 |
| Mackays Body Repairs Ltd | Wholesale & retail | 2026 |
| Mackie Landscapes Ltd | Administrative & support | 2026 |
| Mackie Memorials Limited | Manufacturing | 2021 |
| Mackinnon Publishing Ltd | Information & communication | 2025 |
| Mackk Distribution Ltd | Wholesale & retail | 2024 |
| Mackrell and Thomas Limited | Professional & scientific | 2013 |
| Macks NRG Limited | Financial services | 2024 |
| Maclec Limited | Construction | 2014 |
| Macleod Legal and Maritime Consultancy Limited | Professional & scientific | 2016 |
| Macmillan Ltd | Professional & scientific | 2026 |
| Macon Electrical Limited | Construction | 2018 |
| Macriet Ltd | Real estate | 2024 |
| Macro Balance Ltd | Hospitality | 2017 |
| Macro Magic Software Limited | Administrative & support | 2007 |
| Macro Services Limited | Professional & scientific | 2026 |
| Macs Property Construction Limited | Construction | 2015 |
| Macs: Management and Contracting Services Limited | Professional & scientific | 2024 |
| Mactec Security Systems Limited | Construction | 2004 |
| Macward Travel Ltd | Transport & logistics | 2024 |
| Macyos Properties Ltd | Real estate | 2025 |
| MAD Day OUT Beatles Taxi Tours Ltd | Administrative & support | 2017 |
| MAD Repairs and Maintenance Limited | Transport & logistics | 2018 |
| MAD Saint Studio Ltd | Professional & scientific | 2025 |
| Madafabi Limited | Transport & logistics | 2023 |
| Madalinalimited Limited | Wholesale & retail | 2025 |
| Madcal Ltd | Administrative & support | 2023 |
| Madd Gear UK Limited | Arts & recreation | 2010 |
| Madden Properties Ltd | Real estate | 2024 |
| Maddesons UK Ltd | Hospitality | 2026 |
| Maddex Care Limited | Health & social care | 2025 |
| Maddison Holdings Ltd | Real estate | 2016 |
| Maddox Engineering Limited | Other services | 2025 |
| Made by Meaning Ltd | Information & communication | 2026 |
| Made Impact C.I.C. | Information & communication | 2024 |
| Made to BE CIC | Arts & recreation | 2025 |
| Made to BE MUM Ltd | Hospitality | 2024 |
| Made UP to Move Ltd | Health & social care | 2020 |
| Made With Intent Limited | Information & communication | 2022 |
| Made YOU Stare Ltd | Manufacturing | 2020 |
| Madeira Digitizers Ltd | Professional & scientific | 2023 |
| Madelaine Warburton Consultancy Ltd | Information & communication | 2021 |
| Madesafe UK Ltd | Professional & scientific | 2012 |
| Madhead Music Ltd | Arts & recreation | 2022 |
| Madiba Farms and Estate Ltd | Financial services | 2025 |
| Madina Shop and Go Ltd | Wholesale & retail | 2025 |