| Master Furniture Ltd | Manufacturing | 2022 |
| Master Media Services Ltd | Information & communication | 2024 |
| Master Number Limited | Wholesale & retail | 2026 |
| Masterbuild Roofing Ltd | Construction | 2023 |
| Mastercraft Bedrooms and Interiors Limited | Construction | 2024 |
| Mastercraft Tools Limited | Extraterritorial | 1997 |
| Mastercut Cutting Systems Limited | Manufacturing | 2002 |
| Masters Day Limited | Wholesale & retail | 2025 |
| Mastic Pointing Limited | Construction | 2007 |
| Masunda Limited | Health & social care | 2010 |
| MAT Evans Ltd | Information & communication | 2015 |
| MAT J Property Development Limited | Households | 2021 |
| MAT.13 Limited | Arts & recreation | 2023 |
| Matareh Services Limited | Financial services | 2024 |
| Matcha Alchemy Ltd | Wholesale & retail | 2025 |
| Matchmaker Marketing Limited | Professional & scientific | 2006 |
| Matchpoint Clubs Ltd | Education | 2021 |
| Matchworx Limited | Information & communication | 2025 |
| Matefinder Limited | Extraterritorial | 2022 |
| Material Discourse Ltd | Information & communication | 2017 |
| Material Witness Ltd. | Professional & scientific | 2014 |
| Maternable Ltd | Other services | 2025 |
| Matharu Finance Ltd | Financial services | 2021 |
| Mather Holdings Ltd | Arts & recreation | 2022 |
| Matheson & Whiteley Limited | Professional & scientific | 2013 |
| Mathew & Mathew ( M & M ) Ltd. | Financial services | 2017 |
| Mathew Property Ltd | Construction | 2026 |
| Mathspad Limited | Education | 2021 |
| Matic Media Limited | Information & communication | 1996 |
| Matic Properties Limited | Extraterritorial | 2021 |
| Matilda Convenience Store Ltd | Wholesale & retail | 2025 |
| Matilda Laser and Beauty Clinic Ltd | Other services | 2017 |
| Matilda Limited | Health & social care | 2018 |
| Matiq Group Ltd | Water & waste | 2025 |
| Mativeinc Solutions Limited | Information & communication | 2026 |
| Matlock Boats and Train Ltd | Arts & recreation | 2015 |
| Matnads Limited | Real estate | 2021 |
| Matrix Accounting Services Ltd | Professional & scientific | 2025 |
| Matrix Cladding Limited | Construction | 2025 |
| Matrix Estate Planning Limited | Professional & scientific | 2021 |
| Matrix Frames & Displays Limited | Manufacturing | 2011 |
| Matrix IT Consulting Limited | Information & communication | 2023 |
| Matrix Utilities Ltd | Construction | 2018 |
| Matson Leisure Ltd | Hospitality | 2025 |
| Matsucol Real Estate Limited | Real estate | 2021 |
| Matsya Technologies Ltd | Agriculture & fishing | 2021 |
| Matt Harrison Consulting Limited | Professional & scientific | 2024 |
| Mattersey Developments Limited | Construction | 2021 |
| Mattersey Enterprises Ltd | Real estate | 2025 |
| Matthew Bullock Dentistry Ltd | Health & social care | 2015 |
| Matthew Cragg Ventures Limited | Real estate | 2015 |
| Matthew Gray Editing Ltd | Administrative & support | 2011 |
| Matthew Hall 3D Ltd | Information & communication | 2016 |
| Matthew Lilleker Limited | Construction | 2007 |
| Matthew Sherwood Productions Ltd | Professional & scientific | 2022 |
| Matthewman LA BAU Ltd | Professional & scientific | 2011 |
| Matthews Construction Services Ltd | Construction | 2025 |
| Matthews Wool Shop Limited | Wholesale & retail | 2014 |
| Matto Carpets & Flooring Ltd | Wholesale & retail | 2025 |
| Mauritius Travel (UK) Ltd. | Administrative & support | 2014 |
| Maurizio VON Trapp Productions Limited | Information & communication | 2022 |
| MAV Medicine Limited | Health & social care | 2016 |
| Maveli Restaurant Ltd | Hospitality | 2013 |
| Maven Financial Group Limited | Financial services | 2022 |
| Maven Group Investments Ltd | Real estate | 2025 |
| Maven Technology Services Ltd | Information & communication | 2015 |
| Maven Trade Limited | Wholesale & retail | 2017 |
| Maverick Connections Limited | Construction | 2024 |
| Maverick P D Limited | Construction | 2024 |
| Maverick Portfolio Limited | Real estate | 2026 |
| Maviruya Restaurant Ltd | Hospitality | 2021 |
| Maviruya S11 Ltd | Hospitality | 2025 |
| MAW Plant Hire Limited | Administrative & support | 2017 |
| MAW Premier Homes Ltd | Real estate | 2024 |
| Mawa Estates Ltd | Real estate | 2026 |
| Mawire Media and Technology Limited | Information & communication | 2009 |
| Mawuli Enterprise Ltd | Health & social care | 2015 |
| MAX Frommeld Limited | Professional & scientific | 2013 |
| MAX Power Motors Ltd | Wholesale & retail | 2020 |
| MAX Wheelchairs Limited | Wholesale & retail | 2017 |
| Max-El Controls Limited | Construction | 2012 |
| Max-El Properties Limited | Real estate | 2019 |
| Maxan Consulting Limited | Professional & scientific | 2025 |
| Maxcom Limited | Administrative & support | 1991 |
| Maxelco Ltd | Professional & scientific | 2018 |
| Maxfield Electrical Ltd | Construction | 2025 |
| Maxi Poli Ltd | Wholesale & retail | 2013 |
| Maxigrow Limited | Manufacturing | 1997 |
| Maxim Family Ltd | Hospitality | 2008 |
| Maxim IP Limited | Administrative & support | 2013 |
| Maximia Ltd | Transport & logistics | 2026 |
| Maximo Entertainments Ltd | Information & communication | 2022 |
| Maximum Leisure (Rotherham) Limited | Real estate | 2014 |
| Maximus Construction Services Ltd | Other services | 2024 |
| Maximus Consulting Services Limited | Professional & scientific | 2024 |
| Maxip Ltd | Professional & scientific | 2014 |
| Maxiscope Limited | Administrative & support | 1977 |
| Maxreach Logistics Ltd | Transport & logistics | 2026 |
| Maxs Pizza Ltd | Hospitality | 2025 |
| Maxsolar Ltd | Construction | 2023 |