| Morley Home Improvement Ltd | Construction | 2017 |
| Moroccan Givings Limited | Wholesale & retail | 2026 |
| Morph UK Limited | Professional & scientific | 2001 |
| Morpheus Consultancy Ltd | Professional & scientific | 2025 |
| Mortgage Maker Limited | Financial services | 2024 |
| Mortgage Wheel Ltd | Financial services | 2015 |
| Moseley Chapman & Skemp Solicitors Limited | Professional & scientific | 2008 |
| Moss Evans Ltd | Professional & scientific | 2021 |
| Moss Network Consulting Limited | Real estate | 2023 |
| Mostdudno Properties Ltd | Real estate | 2020 |
| Mostly Management Limited | Other services | 2018 |
| Mostly Marketing Ltd | Administrative & support | 2011 |
| Mostly Websites Limited | Information & communication | 2012 |
| MOT Auto Repairs Ltd | Wholesale & retail | 2023 |
| MOT to Go Ltd | Wholesale & retail | 2021 |
| Motener Ltd | Construction | 2024 |
| Mother Huff CAP Management Ltd | Hospitality | 2021 |
| Mother India Cuisine Limited | Hospitality | 2012 |
| Motion Harrison Electrical Ltd | Construction | 2024 |
| Motivasian Limited | Wholesale & retail | 2018 |
| MOTIVE8 Youth C.I.C. | Education | 2021 |
| Motor Services Sutton Coldfield Ltd | Professional & scientific | 2026 |
| Motor Verso Limited | Information & communication | 2014 |
| Motorlec Services Limited | Construction | 2002 |
| Mount Pleasant Barns Limited | Construction | 2013 |
| Mountcreek Limited | Wholesale & retail | 2025 |
| Mountwood House Management Company Limited | Real estate | 1996 |
| Mouskos Catering Ltd | Administrative & support | 2024 |
| Mouton Noir Clothing Ltd | Wholesale & retail | 2023 |
| Move-On Housing Limited | Real estate | 2003 |
| Moving With Times Limited | Wholesale & retail | 2016 |
| MP & JP Enterprises Ltd | Other services | 2014 |
| MP Global Trading Company Limited | Administrative & support | 2006 |
| MPC Cost Consultancy Ltd | Professional & scientific | 2020 |
| MPH Technical Services Ltd | Administrative & support | 2013 |
| Mpire Executive Ltd | Transport & logistics | 2023 |
| MPK4 Ltd | Health & social care | 2015 |
| MPM International Group & Holdings Ltd | Financial services | 2024 |
| MPM International Ltd | Professional & scientific | 2025 |
| MR Barber CUT Ltd | Other services | 2022 |
| MR Chan's Chinese Restaurant Limited | Hospitality | 2016 |
| MR Chandra (UK) Limited | Information & communication | 2008 |
| MR GAS & Heat Limited | Construction | 2005 |
| MR Humbug Ltd | Professional & scientific | 2007 |
| MR Neville a Johnson Ba-Llb-Nba-Qa (UK) Limited | Wholesale & retail | 2016 |
| MR Neville a Johnson QA and MRS Lucretia M Johnson QA (Mercedes Benz) UK Limited | Extraterritorial | 2021 |
| MR Neville Alphonso Johnson MBA QA and MRS Helen Lisa Beech MBA QA (Lloyds) UK Ltd | Extraterritorial | 2021 |
| MR Party Wall Ltd | Professional & scientific | 2023 |
| MR Watts Lighting Ltd | Wholesale & retail | 2026 |
| Mrgh Ltd | Administrative & support | 2026 |
| MRP Asset Management Ltd | Construction | 2021 |
| MRS K'S Cookery School Ltd | Education | 2024 |
| MRS Lady Lorraine Coleshills Hill RD PUB Limited | Hospitality | 2018 |
| MS2018 Ltd | Wholesale & retail | 2024 |
| MSA Dental Ltd | Health & social care | 2020 |
| MSA Investors Ltd | Real estate | 2018 |
| MSC Car Sales Ltd | Wholesale & retail | 2023 |
| MSD Cottage Limited | Health & social care | 2024 |
| MSF Logistics Ltd | Administrative & support | 2025 |
| MSH Locums Limited | Health & social care | 2005 |
| Msja Properties Limited | Real estate | 2022 |
| MSM Building & Property Services Limited | Real estate | 2002 |
| MSO 99 Limited | Professional & scientific | 2021 |
| MSZ Surveys Ltd | Professional & scientific | 2013 |
| MT GAS Services Ltd | Administrative & support | 2017 |
| MT Holdings Global Limited | Construction | 2023 |
| MTA Medical Services Ltd | Health & social care | 2012 |
| MTE Construction Services Limited | Construction | 2006 |
| MTL Properties Limited | Real estate | 2025 |
| MU Designer Ltd | Wholesale & retail | 2023 |
| MU Sigma Properties Limited | Real estate | 2024 |
| Mubbashara Yasir Ltd | Hospitality | 2021 |
| Mulberry Consulting PT Ltd | Administrative & support | 2025 |
| Mulberry Offices Limited | Administrative & support | 2017 |
| Mullensgrove Holdings Limited | Real estate | 2023 |
| Mulroy Gardens Limited | Households | 2016 |
| Multi Ventures Ltd | Professional & scientific | 2019 |
| Mumma`S BOY Media Limited | Real estate | 2009 |
| Mums Works Limited | Health & social care | 2015 |
| Mumtazproperties Ltd | Real estate | 2024 |
| Munday Power Consulting Limited | Professional & scientific | 2009 |
| Munn Travel Ltd | Administrative & support | 2023 |
| Munvisas Creations Ltd | Wholesale & retail | 2026 |
| MUP Medico Limited | Health & social care | 2022 |
| Muppiri V Consultancy Ltd | Health & social care | 2026 |
| Murcotts Ltd. | Financial services | 2016 |
| Murphy Housing Limited | Real estate | 2025 |
| Murrell Consultancy Limited | Information & communication | 1995 |
| Murugan Medical Services Limited | Health & social care | 2021 |
| Music Monsters Sutton Coldfield Ltd | Education | 2024 |
| Mutec Ltd | Manufacturing | 2023 |
| Mutual-B UK Limited | Wholesale & retail | 2021 |
| Muzaffar Holdings Ltd | Real estate | 2024 |
| Muzaffar Investments Ltd | Financial services | 2024 |
| Mvus Homes Limited | Real estate | 2018 |
| Mvus Limited | Information & communication | 2016 |
| MW Aviation Solutions Limited | Transport & logistics | 2014 |
| MW Cantonese Restaurant Ltd | Hospitality | 2019 |
| Mwhv Power Services Ltd | Energy | 2025 |
| MWV UK (Midlands) Ltd | Information & communication | 2011 |