| Midland Cars Hub Ltd | Wholesale & retail | 2019 |
| Midland Displays Limited | Wholesale & retail | 2002 |
| Midland Stainless Specialists Limited | Manufacturing | 1997 |
| Midlands Cherry Estates Limited | Real estate | 2022 |
| Midlands Prestige Property Ltd | Real estate | 2025 |
| Mikam Trans Ltd | Transport & logistics | 2020 |
| Miko Empowerment Community Interest Company | Education | 2024 |
| Milano City Ltd | Hospitality | 2026 |
| Milano Express Travels Limited | Administrative & support | 2025 |
| Milburngate Phase 2 LLP | | 2023 |
| Miles a Limited | Wholesale & retail | 2024 |
| Milestone Trading Ltd | Construction | 2025 |
| Milkat Limited | Real estate | 2024 |
| Millan Trading Ltd | Hospitality | 2025 |
| Mimikron Parts Ltd | Wholesale & retail | 2026 |
| Mind-Full Consultants Limited | Professional & scientific | 2025 |
| Mindful Orbit - Interstellar Yoga Holistic Healing Ltd | Education | 2023 |
| Minee Monkeys Ltd | Health & social care | 2013 |
| Minerval Management Solutions Limited | Professional & scientific | 2016 |
| Mini Market Oldbury Ltd | Wholesale & retail | 2025 |
| MIR House Limited | Financial services | 2021 |
| MIR Properties Group Limited | Real estate | 2020 |
| Mircor Retail Limited | Hospitality | 2025 |
| Miron Property Group Ltd | Real estate | 2025 |
| Miron Repair Ltd | Wholesale & retail | 2025 |
| Mister Manns Limited | Transport & logistics | 2014 |
| Mitsu Goods Ltd | Wholesale & retail | 2023 |
| Mixologist Bar and Events Ltd | Hospitality | 2024 |
| MJ Car Parts Limited | Wholesale & retail | 2026 |
| MJ UK MAN Power Limited | Construction | 2026 |
| MJ13 Real Estate Limited | Real estate | 2024 |
| MJM Retailers Ltd | Wholesale & retail | 2025 |
| Mjot Transport Limited | Transport & logistics | 2025 |
| Mjsr Group Ltd | Administrative & support | 2026 |
| Mkahlon Transports Ltd | Transport & logistics | 2025 |
| Mkgm Ltd | Other services | 2023 |
| MM Glazing Ltd | Construction | 2023 |
| MM Recovery Ltd | Transport & logistics | 2024 |
| MMA Logistics Limited | Transport & logistics | 2025 |
| MMP Group Logistics Ltd | Transport & logistics | 2024 |
| MMS Developments Ltd | Real estate | 2021 |
| MN Sabir Ltd | Wholesale & retail | 2025 |
| Moats Way Limited | Construction | 2024 |
| Mobile Pizza Limited | Hospitality | 2025 |
| Mobisy Technologies UK Limited | Information & communication | 2019 |
| Model Eyebrows Limited | Other services | 2008 |
| Moden Limited | Manufacturing | 2015 |
| Modern Edge Recruitment (Coventry) Limited | Administrative & support | 2025 |
| Modern Edge Recruitment Ltd | Administrative & support | 2020 |
| Modern Selection Ltd | Construction | 2017 |
| Modren Ltd | Construction | 2026 |
| Moir D. SOT Limited | Wholesale & retail | 2007 |
| Mona Mondo Ltd | Wholesale & retail | 2015 |
| Monath Property Ltd | Real estate | 2025 |
| Monetgrange Ltd | Real estate | 2004 |
| Money LAB United Ltd | Wholesale & retail | 2019 |
| Monkspath Sports Academy Limited | Education | 2021 |
| Monument IT Consulting Ltd | Information & communication | 2018 |
| Monument Properties Ltd | Real estate | 2020 |
| Mooney Ltd | Manufacturing | 2016 |
| Moorfield Initiative Ltd | Information & communication | 2023 |
| Morgan J Limited | Wholesale & retail | 2023 |
| Morris Electrical Installations Limited | Construction | 2013 |
| Morris Motorsport Limited | Professional & scientific | 2017 |
| Mortgages by ABI Limited | Other services | 2023 |
| Mosaso Limited | Wholesale & retail | 2022 |
| MOT Central & Repairs Ltd | Wholesale & retail | 2025 |
| Motorite Protection Ltd | Wholesale & retail | 2025 |
| Movex Delivery Ltd | Transport & logistics | 2025 |
| Movexia Ltd | Transport & logistics | 2026 |
| Moza Khana Ltd | Hospitality | 2026 |
| MR FX B Ltd | Financial services | 2025 |
| MR J S M Dwyer Trauma & Orthopaedic Surgeon Limited | Health & social care | 2015 |
| MR Singh Limited | Construction | 2017 |
| MRB Home Improvements Ltd | Manufacturing | 2025 |
| Mrha Builders Services Ltd | Construction | 2024 |
| MRS FX R Ltd | Financial services | 2025 |
| MSJ Consultus Limited | Information & communication | 2016 |
| MSJ Holdings Limited | Financial services | 2019 |
| MSN Transport U.K. Limited | Transport & logistics | 2025 |
| MSS Pharma Ltd | Professional & scientific | 2021 |
| MSW Industries Limited | Professional & scientific | 2026 |
| MT Removals Limited | Transport & logistics | 2016 |
| Mtistanbul Ltd | Wholesale & retail | 2017 |
| Muderes Parcels Ltd | Transport & logistics | 2024 |
| Mudhugger Limited | Manufacturing | 2014 |
| Mukend Capital Properties Limited | Real estate | 2025 |
| Mukjo Limited | Wholesale & retail | 2025 |
| Multani Removal Ltd | Transport & logistics | 2026 |
| Multicarrier Express Limited | Real estate | 2023 |
| Muneersons Limited | Wholesale & retail | 2026 |
| Murad Khan Consulting Ltd | Arts & recreation | 2021 |
| Muras Trans Ltd | Transport & logistics | 2018 |
| Music Cafe Limited | Information & communication | 2009 |
| Mussa Courier Service Ltd | Transport & logistics | 2026 |
| My Cosmetic Doctor Limited | Health & social care | 2020 |
| Mynards (Cornwall) Limited | Hospitality | 2006 |
| Mynards Holidays Limited | Hospitality | 2006 |
| Mynards Limited | Hospitality | 1977 |
| Mytra Fusion Ltd | Wholesale & retail | 2017 |