| MAC Properties (Leicester) Limited | Real estate | 2022 |
| MAC24 Limited | Agriculture & fishing | 2024 |
| Macgill Ventures Ltd | Real estate | 2024 |
| Madina Multi Mart Limited | Wholesale & retail | 2025 |
| Mahroo Hair & Beauty Ltd | Other services | 2020 |
| MAJ Apparel Limited | Wholesale & retail | 2023 |
| MAJESTIC8 Holdings Limited | Administrative & support | 2023 |
| Makh Support Ltd | Information & communication | 2016 |
| Maliha B Limited | Financial services | 2018 |
| Mamoet Ltd | Transport & logistics | 2012 |
| Mancave Barber Lounge Ltd | Other services | 2019 |
| Mannix Brothers Pianos and Storage Limited | Transport & logistics | 2025 |
| Mannys Simply Delicious Ltd | Hospitality | 2017 |
| Manyonga B Limited | Health & social care | 2020 |
| Marcin Weron Ltd | Extraterritorial | 2017 |
| Markhams (Leicester) Limited | Construction | 2018 |
| Marlene Solutions Ltd | Administrative & support | 2023 |
| Martin House Properties Limited | Real estate | 2008 |
| Mash Healthcare Solutions Ltd | Health & social care | 2021 |
| Master Miles Limited | Education | 2025 |
| Matharu Healthcare Limited | Health & social care | 2023 |
| MAX Energy Savings & EPC Consultant Ltd | Wholesale & retail | 2018 |
| Mbua Satisfactory Solutions Ltd | Administrative & support | 2023 |
| MCL Auto Solutions Ltd | Manufacturing | 2023 |
| Mcodude Travel Limited | Transport & logistics | 2026 |
| MD Lift Solutions Ltd | Professional & scientific | 2026 |
| Meadow Heat Ltd | Construction | 2016 |
| Meadow Pubs Ltd | Hospitality | 2025 |
| Measom Freer & Company Limited | Manufacturing | 1960 |
| Meatboys Ltd | Wholesale & retail | 2026 |
| Medicwork Limited | Health & social care | 2024 |
| Mehar on Wheels Ltd | Transport & logistics | 2025 |
| Melton Orthodontics Ltd | Health & social care | 2017 |
| Mere Way Wines Ltd | Manufacturing | 2022 |
| Meridian Heating Limited | Construction | 2013 |
| Mezko Ltd | Financial services | 2026 |
| MH Insight Ltd | Professional & scientific | 2020 |
| MH Trading Post Limited | Wholesale & retail | 2025 |
| MH Windows & Doors Limited | Manufacturing | 2023 |
| MHE Design and Management Limited | Construction | 2018 |
| Mick and Dens Limited | Wholesale & retail | 2010 |
| Midas Inc Limited | Financial services | 2023 |
| Midcentral Highways Training Ltd | Administrative & support | 2017 |
| Midemikun Ltd | Administrative & support | 2025 |
| Midland Partitions Limited | Construction | 2019 |
| Midland Tile (Leicester) Ltd | Construction | 2008 |
| Midlands Dental Group Limited | Health & social care | 2025 |
| Midlands Industrial Supplies Limited | Wholesale & retail | 2022 |
| Midlands Property & Construction Ltd | Construction | 2025 |
| Mika & Sons Transport Limited | Transport & logistics | 2019 |
| Milled Lead Supplies Ltd | Manufacturing | 2011 |
| Millennial Vision CLO Limited | Wholesale & retail | 2020 |
| Miller Stanley Consulting Limited | Administrative & support | 2015 |
| Milo Sedani Ltd | Real estate | 2026 |
| Mimi's Group Ltd | Manufacturing | 2025 |
| Mini Warriors Ltd | Health & social care | 2019 |
| MK Properties (Leicester) Limited | Households | 2023 |
| MK Solutions (Leicester) Limited | Wholesale & retail | 2021 |
| MKC Group Holdings Ltd | Financial services | 2026 |
| MKC Property Holdings Ltd | Real estate | 2026 |
| MMC Transport Leicester Ltd | Transport & logistics | 2019 |
| MOE7 Barbers Ltd | Other services | 2025 |
| Money Risk Coach Limited | Financial services | 2024 |
| Mont Cherry Ltd | Wholesale & retail | 2014 |
| Mortgage Bridge Limited | Financial services | 2022 |
| Mortimer Services Ltd | Construction | 2025 |
| Mother Wellness Limited | Other services | 2024 |
| Motion MAX UK Ltd | Wholesale & retail | 2025 |
| Motorcast Limited | Wholesale & retail | 2023 |
| Moulton Repairs Ltd | Wholesale & retail | 2018 |
| MR Hundal Builders Ltd | Construction | 2022 |
| MRP Property Solutions Limited | Construction | 2026 |
| MRP Trading Ltd | Wholesale & retail | 2008 |
| MRS T'S Pantry Limited | Hospitality | 2018 |
| Mrvconstructiones Ltd | Construction | 2025 |
| MS Eram Ltd | Construction | 2024 |
| MS Managment Ltd | Wholesale & retail | 2022 |
| Msrk Financial Solutions Limited | Financial services | 2019 |
| MST Tech Ltd | Information & communication | 2016 |
| Muazim Limited | Wholesale & retail | 2024 |
| Mubzz Ltd | Transport & logistics | 2022 |
| Mugauri Care Ltd | Health & social care | 2026 |
| Mullen & Kelly Construction Limited | Construction | 1992 |
| My Future Education Ltd | Wholesale & retail | 2021 |
| Mztconstruction Ltd | Construction | 2025 |
| N S Sahj Limited | Construction | 2020 |
| NAILTASTIC68 Limited | Other services | 2022 |
| Nasag Group Ltd | Transport & logistics | 2024 |
| Natalia George Ltd | Transport & logistics | 2024 |
| Nature's Play Ltd | Education | 2022 |
| ND Skin Aesthetics Ltd | Wholesale & retail | 2021 |
| Near Grab Ltd | Water & waste | 2025 |
| Nedham Foods Ltd | Hospitality | 2023 |
| Nestify Baby Limited | Wholesale & retail | 2024 |
| Netphyre Ltd. | Information & communication | 2001 |
| Neuroability Limited | Health & social care | 2022 |
| Neuroability Services Limited | Health & social care | 2025 |
| New Frontier Ventures Limited | Transport & logistics | 2018 |
| New Leaf Social Care Limited | Health & social care | 2023 |
| New Skin Aesthetics Ltd | Other services | 2023 |