| Meringue Bakery & Cafe Ltd | Wholesale & retail | 2013 |
| Meritcove Properties Limited | Real estate | 1983 |
| Merlin Design and Survey LLP | | 2024 |
| Mert Homes Ltd | Construction | 2021 |
| MES Sweet Ltd | Hospitality | 2025 |
| Meshviz Ltd | Information & communication | 2015 |
| Messung Ltd | Manufacturing | 2024 |
| META-4 Ways Ltd | Professional & scientific | 2024 |
| Metamorphous Consulting Limited | Professional & scientific | 2014 |
| Metapic Limited | Manufacturing | 1960 |
| Metermedics Limited | Construction | 2015 |
| Metersmart Limited | Energy | 2010 |
| Methodology MAN Ltd | Professional & scientific | 2023 |
| Metrix Courier Limited | Transport & logistics | 2018 |
| Meynell Hunt Developments Ltd | Construction | 2024 |
| MFA (Derbyshire) Ltd | Financial services | 2001 |
| MFR Engineering Services Ltd | Manufacturing | 2017 |
| MFS Property Holdings Ltd | Real estate | 2026 |
| MG Electrical (Derbyshire) Limited | Manufacturing | 2011 |
| MGB Development's Ltd | Households | 2025 |
| MGF Consulting Limited | Information & communication | 1997 |
| MGF Site Solutions Limited | Wholesale & retail | 2015 |
| MGH Splicing Limited | Information & communication | 2022 |
| MGM UK AF Limited | Wholesale & retail | 2016 |
| Mguild Project Services Limited | Professional & scientific | 2016 |
| MHJ Consulting Ltd | Professional & scientific | 2025 |
| Mhtep Holdings Limited | Administrative & support | 2017 |
| Miarose Limited | Information & communication | 2023 |
| Mica HDD Limited | Professional & scientific | 2026 |
| Micawber Consultancy Limited | Professional & scientific | 2015 |
| Michael Henshaw Development Ltd | Professional & scientific | 2018 |
| Michael Lettall Peaceful Pets Limited | Manufacturing | 2026 |
| Michael Lord (Plumbing & Heating) Limited | Construction | 2022 |
| Michael Wisher Limited | Administrative & support | 2017 |
| Michala D Taylor Consultancy Limited | Professional & scientific | 2025 |
| Michelle’S Food Hygiene Ltd | Hospitality | 2026 |
| Micon RMC Limited | Manufacturing | 2003 |
| Micro Leasing Ltd | Administrative & support | 2020 |
| Midall & Stones Electrical Services Limited | Construction | 1999 |
| Midall & Stones Holdings Limited | Financial services | 2025 |
| Midall & Stones Property Limited | Real estate | 2016 |
| Middlec Software Limited | Information & communication | 1999 |
| Middleton Estate Agents Ltd | Real estate | 2019 |
| Middleton Management Services Ltd | Wholesale & retail | 2018 |
| Midini Healthcare Services Ltd Ltd | Health & social care | 2020 |
| Midland Conveyors Holdings Ltd | Financial services | 2023 |
| Midland Conveyors Ltd | Manufacturing | 2017 |
| Midland Counties Canine Society Limited | Other services | 2018 |
| Midland ENG Limited | Manufacturing | 2020 |
| Midland Falcons Ltd | Wholesale & retail | 2022 |
| Midland Printing Company (Holdings) Limited | Manufacturing | 2025 |
| Midland Project Solutions Limited | Professional & scientific | 2015 |
| Midlands CIS Ltd | Professional & scientific | 2024 |
| Midlands Golf Buggies Limited | Wholesale & retail | 2016 |
| Midlands Mediation Limited | Professional & scientific | 2016 |
| Midlands Printing Company Limited | Manufacturing | 2014 |
| Miete Properties Ltd | Construction | 2021 |
| MIG LA Ltd | Education | 2026 |
| Mikenjuma Properties Limited | Real estate | 2022 |
| Mikenjuma UK Limited | Health & social care | 2016 |
| Miles Beyond Consulting Ltd | Financial services | 2024 |
| Milestone Concierge Holdings Limited | Financial services | 2021 |
| Milestone Concierge Services Limited | Professional & scientific | 2013 |
| Milestone Concierge Trustees Limited | Extraterritorial | 2021 |
| Milestone Corporate Finance Limited | Professional & scientific | 2020 |
| Milestone Development Solutions Ltd | Construction | 2015 |
| Milestone Entertainment Limited | Arts & recreation | 2025 |
| Milestone FP Ltd | Financial services | 2002 |
| Milestone JV LLP | | 2016 |
| Mill House Internet Services Limited | Information & communication | 1995 |
| Mill Lock Construction Limited | Construction | 2000 |
| Mill Lock Developments Limited | Extraterritorial | 2011 |
| Millbrook Precision Engineering Limited | Manufacturing | 2001 |
| Millennium Homecare Services Limited | Other services | 2000 |
| Miller Solutions Limited | Information & communication | 2002 |
| Millerstouchacademy Ltd | Education | 2026 |
| Millhouse Promotions Limited | Wholesale & retail | 2005 |
| Million Pound Draw Ltd | Arts & recreation | 2026 |
| Millstone Construction Ltd | Construction | 2026 |
| Millstone Hydro Ltd | Manufacturing | 2022 |
| Millthyme Limited | Manufacturing | 2021 |
| Milltown Management Ltd | Households | 2014 |
| Milly Mops Limited | Administrative & support | 2025 |
| Milton's Holding Company Ltd | Financial services | 2020 |
| MIM Systems (EOT) Limited | Financial services | 2024 |
| Mimi Thredz Limited | Wholesale & retail | 2025 |
| Mind & Move CIC | Education | 2026 |
| Mind Recovery Limited | Health & social care | 2017 |
| Mini Digger & Small Plant Hire Ltd | Administrative & support | 2024 |
| Minikiss Store Limited | Wholesale & retail | 2026 |
| Minimas Limited | Real estate | 2006 |
| Mining Surveys (U.K.) Limited | Professional & scientific | 1989 |
| Minorfern Limited | Wholesale & retail | 1978 |
| Mint Consulting (CRM) Limited | Information & communication | 2023 |
| Mintdale Engineering Limited | Manufacturing | 1984 |
| Mircea Moian Ltd | Health & social care | 2019 |
| Mission Motor Company Ltd | Wholesale & retail | 2024 |
| Mistley Quayside Management Limited | Households | 2000 |
| Misza-Transport Ltd | Transport & logistics | 2018 |
| Mitchell Brentnall Design Ltd | Professional & scientific | 2019 |