| Magic View Decorating Ltd | Construction | 2017 |
| Magic WOK Wycombe Ltd | Hospitality | 2021 |
| Magical MAS Ltd | Arts & recreation | 2026 |
| Maglo Ltd | Information & communication | 2022 |
| Magna 1PLUS1 Production Limited | Information & communication | 2023 |
| Magna Autos Limited | Wholesale & retail | 2025 |
| Magna Catering Limited | Hospitality | 2022 |
| Magna Estate Limited | Real estate | 2021 |
| Magna Hollywood Limited | Information & communication | 2024 |
| Magna Residential Limited | Real estate | 2026 |
| Magna Studios Limited | Information & communication | 2023 |
| Magna Surrey Street Limited | Information & communication | 2025 |
| Magnetism Consulting Limited | Professional & scientific | 2024 |
| Magnolia Dining Ltd | Hospitality | 2019 |
| Magnolia Park Wycombe Limited | Hospitality | 2014 |
| Magnus Publications Limited | Professional & scientific | 2013 |
| Magpie Travel Limited | Transport & logistics | 2007 |
| Magt Global Limited | Information & communication | 2025 |
| Maguire Consulting Group Limited | Professional & scientific | 2015 |
| Maguire's Scaffolding Limited | Construction | 2021 |
| MAH Resolutions Limited | Professional & scientific | 2016 |
| Maha Accountancy Ltd | Professional & scientific | 2021 |
| Maha VSV Homes Limited | Real estate | 2026 |
| Maha VSV Limited | Information & communication | 2016 |
| Mahdavi Property Ltd | Real estate | 2024 |
| Mahmood & Sons Property Limited | Real estate | 2024 |
| Maidavale Property Ltd | Real estate | 2020 |
| Maiden Global Holdings Ltd. | Financial services | 2010 |
| Maidenhead Fire Safety Limited | Public administration | 2023 |
| Mailsports Limited | Wholesale & retail | 2024 |
| Main Line Homes Limited | Real estate | 2021 |
| Main Line Travel Limited | Transport & logistics | 2023 |
| Maison Ceylan Limited | Wholesale & retail | 2025 |
| Maison DES Belles Ltd | Other services | 2022 |
| Maison XO Ltd | Wholesale & retail | 2025 |
| Maison-Chef Ltd | Hospitality | 2018 |
| Majestic Chemicals Limited | Manufacturing | 2004 |
| Majestic+ Heating & GAS Ltd | Construction | 2025 |
| Majitu Healthcare Ltd | Health & social care | 2015 |
| Major Heat Group Ltd | Wholesale & retail | 2025 |
| Majum Luxury Limited | Real estate | 2025 |
| MAK Cars Ltd | Wholesale & retail | 2023 |
| MAK Foods (HW) Limited | Wholesale & retail | 2021 |
| MAK Mobile Tyres & Recovery Ltd | Wholesale & retail | 2025 |
| MAK Motors (H.W) Ltd | Wholesale & retail | 2015 |
| Maka Boxing Ltd | Education | 2026 |
| Make YOU Move Records (Mymr) Limited | Information & communication | 2020 |
| Makhan Capital Ltd | Real estate | 2025 |
| Making Places Together Ltd | Professional & scientific | 2021 |
| Makk LOW Carbon Installations Ltd | Construction | 2025 |
| Maksyauto 17 Ltd | Other services | 2015 |
| Maksym Ltd | Construction | 2016 |
| Maktek Solutions Ltd | Real estate | 2015 |
| Malabiz PVT Ltd | Administrative & support | 2025 |
| Malc Portfolio Ltd | Real estate | 2025 |
| Malgam Ltd | Wholesale & retail | 2017 |
| Mali Management Group Limited | Professional & scientific | 2019 |
| Malik One Ltd | Other services | 2014 |
| Maliks & Sons Limited | Wholesale & retail | 2022 |
| Malik’S Furniture Hub Ltd | Wholesale & retail | 2025 |
| Mallard & Claret Ltd | Professional & scientific | 2016 |
| Mallard Living Limited | Real estate | 2025 |
| Malts Construction Ltd | Construction | 2026 |
| Mama Associates Limited | Information & communication | 2010 |
| MAMAS53 Limited | Real estate | 2024 |
| Mambagate Limited | Transport & logistics | 2021 |
| Mamtechvis Limited | Information & communication | 2021 |
| Mandala FX Ltd | Professional & scientific | 2022 |
| Mandala Property Services Limited | Real estate | 2018 |
| Mandy Gosling Therapy Limited | Health & social care | 2022 |
| Mangla Ltd | Real estate | 2024 |
| Mango Management Training Limited | Hospitality | 2022 |
| Manifest Fragrances Limited | Wholesale & retail | 2025 |
| Manigo Ltd | Professional & scientific | 2025 |
| Mann Sharma Ltd | Professional & scientific | 2022 |
| Mannats Beauty Ltd | Other services | 2022 |
| Mano Estates Limited | Real estate | 2025 |
| Manolo Construction Ltd | Construction | 2024 |
| Manor Cars High Wycombe Ltd. | Wholesale & retail | 2013 |
| Manor Court (Prescot) Management Company Limited | Extraterritorial | 2008 |
| Manor Farm Residents Association Limited | Real estate | 1970 |
| Manor Farm Road Alperton Management Limited | Real estate | 2003 |
| Maplin Group Ltd | Financial services | 2023 |
| Maplin Property Ltd | Manufacturing | 2015 |
| Maqamam Mahmudah Limited | Other services | 2021 |
| Maquisard Ltd | Professional & scientific | 2013 |
| MAR Sleeva Limited | Transport & logistics | 2025 |
| Maratom Ltd | Transport & logistics | 2018 |
| Maraval Limited | Professional & scientific | 2014 |
| Marble & Granite (UK) Services Ltd | Manufacturing | 2010 |
| Marble & Granite Investments Ltd | Extraterritorial | 2015 |
| Marble and Quartz Designs Limited | Professional & scientific | 2023 |
| Marble and Quartz Specialist Limited | Health & social care | 2016 |
| Marcaro Limited | Information & communication | 2023 |
| Marcel Animal Orthopaedics Ltd | Professional & scientific | 2017 |
| Marcmart Property Investments Limited | Real estate | 2025 |
| Marcon Building Services Limited | Construction | 2017 |
| Mares Holdings Ltd | Real estate | 2023 |
| Marf Accountants Limited | Professional & scientific | 2004 |
| Marfina Estates Ltd | Real estate | 2023 |