| Mdhd Limited | Hospitality | 2014 |
| MDK London Group Limited | Administrative & support | 2019 |
| MDM Windows & Doors Ltd | Construction | 2016 |
| MDP Tech Limited | Wholesale & retail | 2025 |
| MDS Scaffolding Limited | Construction | 2011 |
| ME Time at Home Limited | Professional & scientific | 2016 |
| Meadows Electrical Ltd | Construction | 2017 |
| Meanygate Garage Limited | Wholesale & retail | 2011 |
| Measham 1 Ltd | Real estate | 2020 |
| MEC Coatings & Flooring Ltd | Wholesale & retail | 2019 |
| MED Factor Limited | Health & social care | 2022 |
| MED Kobani Ltd | Wholesale & retail | 2016 |
| Medex Health Group Ltd | Health & social care | 2023 |
| Medex Healthcare Limited | Health & social care | 2022 |
| Medex Rehab Limited | Health & social care | 2018 |
| Media Experiences Leasing Limited | Information & communication | 2020 |
| Mediavu Limited | Professional & scientific | 2015 |
| Medical Equipment Supplies and Management Holdings Limited | Professional & scientific | 2012 |
| Medical Equipment Supplies and Management Ltd | Wholesale & retail | 2007 |
| Medical-Legal Appointments Limited | Administrative & support | 1990 |
| Medics Travel Limited | Education | 2000 |
| Mediterranean Bistro Limited | Hospitality | 2024 |
| Medway Facilities Group Limited | Financial services | 2017 |
| Medway Mechanical Services Limited | Construction | 2026 |
| Medway Services Limited | Construction | 2021 |
| Medwells Care Ltd | Health & social care | 2022 |
| MEEHOL52 Limited | Households | 2025 |
| Meko Barbers Limited | Other services | 2024 |
| Melrose Investments & Management Services Ltd. | Real estate | 1998 |
| Melrose RC Limited | Health & social care | 2024 |
| Melt & Munch Ltd | Hospitality | 2025 |
| Melverley Drive Ltd | Real estate | 2026 |
| Meme Properties Ltd | Real estate | 2020 |
| Memorycow Ltd | Extraterritorial | 2016 |
| Mercato Capital Limited | Administrative & support | 2024 |
| Mercer & Barker Ltd | Wholesale & retail | 2019 |
| Merchandise 4 Impact Limited | Professional & scientific | 2022 |
| Mercia Partnership (UK) Ltd | Education | 2000 |
| Meridian Automation Ltd | Professional & scientific | 2022 |
| Meridian Crest Group Limited | Financial services | 2026 |
| Meridian Funeral Home Limited | Other services | 2013 |
| Merko Auto Ltd | Wholesale & retail | 2026 |
| Merlin Cycles Limited | Wholesale & retail | 1993 |
| Mersy Chicken Ltd | Hospitality | 2018 |
| Mesh Internet Limited | Information & communication | 2005 |
| MET Services Ltd | Construction | 2018 |
| Metal and Glass Design Limited | Construction | 2018 |
| Metal Treatment Experts Limited | Manufacturing | 2025 |
| Meter PAY Ltd | Energy | 2025 |
| Metric Developments Ltd | Construction | 2019 |
| Metshaw Construction Ltd | Construction | 2018 |
| Metta Move Limited | Arts & recreation | 2019 |
| Metvil Ltd | Information & communication | 2014 |
| MFA Property Developments Ltd | Real estate | 2025 |
| MG Commercial North West Ltd | Professional & scientific | 2020 |
| MG Millbrook Limited | Financial services | 2018 |
| MG Services (NW) Ltd | Professional & scientific | 2021 |
| MG Telematics Limited | Wholesale & retail | 2016 |
| MGF Wholesale & Distribution Ltd | Wholesale & retail | 2026 |
| Mgfl Haulage Ltd | Transport & logistics | 2005 |
| MH 888 Art Gallery Ltd | Arts & recreation | 2024 |
| MH Commercial Management Limited | Professional & scientific | 2014 |
| MH Cuisine Ltd | Hospitality | 2025 |
| MH Developments & Projects Limited | Construction | 2018 |
| MHS Technical Solutions Ltd | Construction | 2021 |
| Mhwellbeing Limited | Health & social care | 2015 |
| MIA C Services Ltd | Administrative & support | 2018 |
| MIA Living Ltd | Administrative & support | 2018 |
| MIB Limited | Manufacturing | 2002 |
| Michael Barnes Driving Services Ltd | Transport & logistics | 2023 |
| Michael Construction Ltd | Construction | 2014 |
| Michael Jane Architecture Ltd | Professional & scientific | 2021 |
| Michael Sewell Photography Ltd | Professional & scientific | 2010 |
| Michelle Howard Consulting Ltd | Professional & scientific | 2022 |
| Micky MOO Logistics Ltd | Transport & logistics | 2025 |
| Micro Computer Workshops Limited | Information & communication | 1984 |
| Micro Inns Ltd | Hospitality | 2026 |
| Microevitech Consulting Group UK Ltd | Professional & scientific | 2015 |
| Microevitech Limited | Professional & scientific | 2017 |
| Microworld Computers UK Limited | Wholesale & retail | 2012 |
| Mida Bros Ltd | Hospitality | 2023 |
| Midas Global Limited | Wholesale & retail | 2017 |
| Midas Touch Design & Landscape Centre Limited | Administrative & support | 2016 |
| Middleton Barton Asset Valuation Limited | Administrative & support | 2016 |
| Middleton Barton Holdings Limited | Administrative & support | 2018 |
| Midland GAS Ltd | Construction | 2017 |
| Midlands Logistic Solutions Ltd | Transport & logistics | 2020 |
| Miella LET Ltd | Real estate | 2024 |
| MIH Catering Ltd | Hospitality | 2025 |
| Mike Farr Trading Ltd | Professional & scientific | 2018 |
| Mike Harrison Commercial Services Ltd | Professional & scientific | 2020 |
| Mike Hawksey Transport Ltd | Transport & logistics | 2017 |
| Mike Heaton Ltd | Transport & logistics | 2015 |
| Mike Webb Transport Ltd | Transport & logistics | 2026 |
| Mill and Press Limited | Wholesale & retail | 2016 |
| Miller Lane Ltd | Construction | 2024 |
| Millersdale Management Company Ltd | Real estate | 2012 |
| Millfield Osceola Financial Consultancy Limited | Financial services | 2001 |
| Millfields Care Services Ltd | Health & social care | 2020 |
| Millhouse Plant and Construction Limited | Construction | 2015 |