| ML Tech Group Limited | Information & communication | 2018 |
| MLC Retail Limited | Wholesale & retail | 2014 |
| MLM Global Solutions Ltd | Professional & scientific | 2026 |
| MLS Infrastructure Limited | Construction | 2023 |
| MLT (Chesterfield) Limited | Construction | 2012 |
| MMC Haulage Limited | Administrative & support | 2022 |
| Mmmgifts Ltd | Manufacturing | 2026 |
| MMV Sales Assistants Ltd | Wholesale & retail | 2023 |
| MN Interiors Limited | Wholesale & retail | 2017 |
| MNM Family Ltd | Health & social care | 2025 |
| MO Tait Ltd | Administrative & support | 2022 |
| Moai Systems Ltd | Information & communication | 2025 |
| Mobile Engineering Solutions Limited | Professional & scientific | 2017 |
| Mobile Recording Limited | Professional & scientific | 2008 |
| Mobility Scooter Traders Ltd | Wholesale & retail | 2023 |
| Mobin Company Ltd | Other services | 2019 |
| Mocha Coffee Houses Limited | Real estate | 1956 |
| Mode-Dev Limited | Construction | 2022 |
| Modrn Skin Clinic Ltd | Other services | 2025 |
| Mokiddiz Enterprises Ltd | Administrative & support | 2018 |
| Moldova SY Ltd | Wholesale & retail | 2018 |
| Mollys Jiffys Limited | Hospitality | 2024 |
| Momentum Fitness and Health Ltd | Professional & scientific | 2021 |
| Momo Enterprises Limited | Wholesale & retail | 2015 |
| Moneypennys Business Solutions Limited | Hospitality | 2003 |
| Monsoon Foods (Mansfield) Ltd | Wholesale & retail | 2013 |
| Monument Security Limited | Administrative & support | 2020 |
| Moon Inc. Properties Ltd | Real estate | 2020 |
| Moon Medical Services Limited | Health & social care | 2019 |
| Moon Predictions Limited | Other services | 2001 |
| Moore Jones Limited | Financial services | 2019 |
| Moorfield Construction Limited | Construction | 2021 |
| Moorland Falconry Supplies Limited | Agriculture & fishing | 2018 |
| Moorside Construction Limited | Construction | 2010 |
| Mopar Trans Ltd | Transport & logistics | 2026 |
| Mophizy Ltd | Hospitality | 2023 |
| MORE4LESS Property Solutions Ltd | Administrative & support | 2026 |
| Morgan Braddox Limited | Construction | 2021 |
| Morgan Fairford Consulting Ltd | Real estate | 2016 |
| Morgan Wright Limited | Wholesale & retail | 2013 |
| Morina Ltd | Other services | 2013 |
| Morleys of Nottingham Ltd | Construction | 2014 |
| Morlighem Ltd | Professional & scientific | 2025 |
| Morton Properties Management Services Limited | Construction | 2003 |
| Moss D Limited | Wholesale & retail | 2026 |
| Mothers’ Nature Ltd | Manufacturing | 2025 |
| Motion 5 Exhibitions Ltd | Construction | 2007 |
| Moto Vuoto Ltd | Wholesale & retail | 2026 |
| Motorsport Electrical Products Limited | Wholesale & retail | 2003 |
| Mouser Electronics Inc. | | 2011 |
| Move IT With MEE Removals Ltd | Transport & logistics | 2021 |
| Moxon Training & Consultancy Ltd | Professional & scientific | 2025 |
| MP Spencer Ltd | Administrative & support | 2022 |
| MP5WORKS Ltd | Manufacturing | 2019 |
| MPC Industrial Coatings Limited | Administrative & support | 2010 |
| MPH Optical Limited | Wholesale & retail | 2017 |
| MPJ Design Associates Ltd | Administrative & support | 2007 |
| MPRODUCTIONTIME2SHOW CIC | Other services | 2023 |
| MR Coaching & Consultancy Ltd | Education | 2021 |
| MR Construction (Mansfield) Limited | Construction | 2023 |
| MR G Sparrow Ltd | Construction | 2015 |
| MR G'S Collection Limited | Hospitality | 2014 |
| MR News and Booze Limited | Wholesale & retail | 2025 |
| MR Steel Limited | Wholesale & retail | 2016 |
| MR Transport Nottingham Ltd | Transport & logistics | 2023 |
| MR Vapex Heanor Ltd | Other services | 2019 |
| MR. G’S Maintenance Services Limited | Administrative & support | 2021 |
| MRC Properties Ltd | Real estate | 2024 |
| MRK (Leicester) Ltd | Wholesale & retail | 2018 |
| MRP Financial Planning Ltd | Professional & scientific | 2022 |
| MRS Training & Rescue Limited | Professional & scientific | 2002 |
| Mrsl Trustee Limited | Other services | 2014 |
| Mrufc Limited | Arts & recreation | 2016 |
| Mrufc Trading Limited | Arts & recreation | 2016 |
| MS Composites Ltd | Construction | 2017 |
| MS Financial Solutions Ltd | Financial services | 2016 |
| Msdr Stores Limited | Wholesale & retail | 2025 |
| MSG & Family Ltd | Real estate | 2020 |
| MSG Technic Marketing Ltd | Wholesale & retail | 2019 |
| MSM Electrical Ltd | Construction | 2018 |
| MSO Consultants Limited | Extraterritorial | 2015 |
| MSO Productions Limited | Arts & recreation | 2010 |
| MSU Consulting Ltd | Transport & logistics | 2015 |
| Mswf Ltd | Wholesale & retail | 2024 |
| MTB Elite Logistics Ltd | Transport & logistics | 2023 |
| MTB Estates Ltd | Real estate | 2019 |
| MTD Accountancy Hub Ltd | Professional & scientific | 2025 |
| MTD Landlord Services Ltd | Information & communication | 2026 |
| MTG Comms Limited | Construction | 2011 |
| MTW Mech Services Ltd | Professional & scientific | 2022 |
| Mtzck Ltd | Wholesale & retail | 2025 |
| Mugurex Limited | Transport & logistics | 2019 |
| Multideal Limited | Professional & scientific | 2010 |
| Multinvest 23 Limited | Real estate | 2023 |
| Multitudex Limited | Wholesale & retail | 2014 |
| Munster Progear Ltd | Wholesale & retail | 2022 |
| Musahab and Co Ltd | Wholesale & retail | 2026 |
| Museum Motors Limited | Wholesale & retail | 2023 |
| Musgrove Strategic Advisors Ltd | Professional & scientific | 2025 |
| Musson Developments Ltd | Real estate | 2025 |