| Maison Cottonverse Ltd | Manufacturing | 2026 |
| Maison DES Petits Nursery Ltd | Education | 2025 |
| Maison Reeves Ltd | Wholesale & retail | 2024 |
| Majamial Ltd | Health & social care | 2018 |
| Majestic Sbct Ltd | Wholesale & retail | 2023 |
| Majestik Food (UK) Limited | Hospitality | 2003 |
| Major Foods Limited | Wholesale & retail | 2013 |
| MAK Pharma Ltd | Wholesale & retail | 2023 |
| MAK Wear Ltd | Wholesale & retail | 2021 |
| MAK10 Ltd | Wholesale & retail | 2019 |
| Makaan Enterprises Limited | Real estate | 2018 |
| Makaan Ltd | Real estate | 2016 |
| Make Your Mark B&D CIC | Health & social care | 2019 |
| Makeup Members Ltd | Other services | 2025 |
| Makoz Group Limited | Arts & recreation | 2022 |
| Makstar Ltd | Information & communication | 2014 |
| Malakit Singh Ltd | Construction | 2024 |
| Malavita Ltd | Information & communication | 2020 |
| Malearn Limited | Education | 2015 |
| Malgar Trading Ltd | Wholesale & retail | 2026 |
| Malhi Construction (Wolve) Limited | Construction | 2014 |
| Mali Restaurant Ltd | Hospitality | 2018 |
| Maliha Ecommerce Ltd | Wholesale & retail | 2025 |
| Malik Awan Construction Limited | Construction | 2019 |
| Malik Brothers Trading Ltd | Wholesale & retail | 2019 |
| Malik Gadgets Ltd | Manufacturing | 2019 |
| Malik Universal Trade Ltd | Wholesale & retail | 2023 |
| Malindi Care Services Limited | Health & social care | 2016 |
| Malita International College Limited | Education | 2022 |
| Mallu Claims Limited | Wholesale & retail | 2025 |
| Mallu Mechanics.Uk Ltd | Wholesale & retail | 2024 |
| Malui Limited | Real estate | 2016 |
| Maly Ltd | Administrative & support | 2023 |
| Mamanie Property Management Ltd | Real estate | 2021 |
| Mammamaternity Ltd | Wholesale & retail | 2025 |
| Mamsm Investments Ltd | Real estate | 2023 |
| MAN Made Plus Limited | Administrative & support | 2018 |
| MAN Made Properties Ltd | Real estate | 2021 |
| MAN Singh Limited | Construction | 2022 |
| Manage Outsource Services Limited | Administrative & support | 2025 |
| Manama Limited | Wholesale & retail | 2020 |
| Mancini Solutions Ltd | Construction | 2025 |
| Mandris Ltd | Wholesale & retail | 2016 |
| Maneemilestogo Ltd | Arts & recreation | 2025 |
| Manfruut Limited | Agriculture & fishing | 2019 |
| Mangata Global Limited | Professional & scientific | 2024 |
| Mango Fresh Limited | Wholesale & retail | 2024 |
| Manitar Consulting Ltd | Professional & scientific | 2025 |
| Manjit Sangha Limited | Real estate | 2024 |
| Mank Private Ltd | Wholesale & retail | 2014 |
| Mann Construction Group Ltd | Construction | 2025 |
| Manna Mission Church UK | Other services | 2011 |
| Mannan&Jagriti Trading Limited | Wholesale & retail | 2025 |
| Mannix Luxe Cleaning Ltd | Administrative & support | 2026 |
| Manor Living Ltd | Wholesale & retail | 2026 |
| Manorline Limited | Other services | 2024 |
| Manpreet SINGH2 Ltd | Construction | 2020 |
| Manshib Caffe Limited | Wholesale & retail | 2015 |
| Manshib Telecoms Limited | Information & communication | 2013 |
| Manson Estate Ltd | Real estate | 2011 |
| Mantas Construction Ltd | Construction | 2020 |
| Mantec College UK Ltd | Education | 2010 |
| Mantrix Management Consultancy Ltd | Professional & scientific | 2025 |
| Manuel Business Consultants Ltd | Information & communication | 2012 |
| Manuela Ltd | Administrative & support | 2023 |
| Manx Shearwater Limited | Administrative & support | 2024 |
| Manzoor & Sons Ltd | Wholesale & retail | 2025 |
| Mapj Ltd | Transport & logistics | 2025 |
| Maple Krest Ltd | Construction | 2019 |
| Maple Wharf Properties Holdings Limited | Financial services | 2026 |
| Maple Wharf Properties Ltd | Financial services | 2025 |
| Maplestead Ltd | Real estate | 2026 |
| MAR Express London Ltd | Wholesale & retail | 2021 |
| Mar-Bee London Ltd. | Wholesale & retail | 2017 |
| Marblearch Ltd | Health & social care | 2011 |
| Marcantonio Foods Limited | Extraterritorial | 2016 |
| March DPF Service Ltd | Wholesale & retail | 2025 |
| Mardol J Consulting & Support Services Ltd | Professional & scientific | 2025 |
| Marevci Motors Ltd | Wholesale & retail | 2018 |
| Marhaba Perfumes Ltd | Wholesale & retail | 2025 |
| Maria and SAM Immigration Advisers Ltd | Professional & scientific | 2026 |
| Maria Maria (U.K) Limited | Hospitality | 2024 |
| Maria OR Mariam Ltd | Health & social care | 2025 |
| Maria Trading Limited | Wholesale & retail | 2025 |
| Marian Logistics Ltd | Transport & logistics | 2015 |
| Marian Team Ltd | Construction | 2024 |
| Marianna Pharma Limited | Wholesale & retail | 2022 |
| Marie Jane Ltd | Wholesale & retail | 2022 |
| Mario Ghost Bakery Ltd | Manufacturing | 2023 |
| Mario Trade Ltd | Construction | 2020 |
| Mark MAN Transport Limited | Transport & logistics | 2018 |
| Market by Mazzi Ltd | Wholesale & retail | 2025 |
| Market Route Limited | Wholesale & retail | 2026 |
| Market Tasty Bites Limited | Hospitality | 2025 |
| Markland Mills Ltd | Real estate | 2017 |
| Marla Security Services Ltd | Administrative & support | 2021 |
| Marmer UK Limited | Manufacturing | 2006 |
| Marrers, Miksy and Mumu Limited | Health & social care | 2025 |
| Mars Consulting Services Ltd | Professional & scientific | 2014 |
| Marsden Media Group Limited | Professional & scientific | 2015 |