| MOT & Motor Services Ltd | Wholesale & retail | 2022 |
| MOT Testing Centre Ltd | Wholesale & retail | 2016 |
| MOT Testing Ltd | Wholesale & retail | 2018 |
| Mothball Studios Ltd | Wholesale & retail | 2025 |
| Mother &Daughters Ltd | Health & social care | 2024 |
| Motion to Movement Ltd | Arts & recreation | 2026 |
| Motivated People Group Ltd | Administrative & support | 2021 |
| Motlhone Limited | Health & social care | 2022 |
| Motogear Marketing Limited | Wholesale & retail | 1972 |
| Motor Glaze Birmingham Limited | Wholesale & retail | 2025 |
| Motor Land 2008 Limited | Wholesale & retail | 2008 |
| Motor Mobile Recovery Ltd | Wholesale & retail | 2024 |
| Motorify Ltd | Wholesale & retail | 2024 |
| Moulali Medical Innovations Limited | Professional & scientific | 2026 |
| Mount Housing Association Limited | Administrative & support | 1992 |
| Move&Safetime Ltd | Transport & logistics | 2021 |
| Moving Boxes UK Limited | Wholesale & retail | 2014 |
| Moznier Ltd | Transport & logistics | 2024 |
| MP Eyecare Ltd | Wholesale & retail | 2026 |
| MP Property Group Ltd | Real estate | 2023 |
| MP Trade Hub Ltd | Wholesale & retail | 2026 |
| MPA Associates Ltd | Administrative & support | 2011 |
| MPH Driving Ltd | Transport & logistics | 2023 |
| Mpilo Healthcare Ltd | Health & social care | 2026 |
| MPL Real Estate Ltd | Real estate | 2021 |
| MPM Project Services Limited | Construction | 2024 |
| MPN Logistics Ltd | Transport & logistics | 2019 |
| MPT Pharma Limited | Administrative & support | 2006 |
| MR 1 Vape Ltd | Other services | 2024 |
| MR Chef (Walsall) Ltd | Hospitality | 2026 |
| MR Chipps Ltd | Hospitality | 2018 |
| MR Foam Ltd | Manufacturing | 2018 |
| MR G'Z Aldridge Limited | Hospitality | 2025 |
| MR GAS FIX Limited | Other services | 2018 |
| MR Grill Pizza and Peri Peri Ltd | Hospitality | 2025 |
| MR Interiors & Heating Ltd | Construction | 2026 |
| MR LAL Guarding Ltd | Administrative & support | 2026 |
| MR Rice Limited | Wholesale & retail | 2009 |
| MR Salvage Ltd | Wholesale & retail | 2025 |
| MR T First Limited | Hospitality | 2025 |
| MR T Housing Limited | Real estate | 2025 |
| MR Tiles and Carpenter Ltd | Construction | 2022 |
| MR Utilities Ltd | Other services | 2024 |
| MR Walsall Ltd | Wholesale & retail | 2023 |
| MRANDMRSMUSIC24 Ltd | Wholesale & retail | 2024 |
| MRB Investments Limited | Construction | 2022 |
| MRF Traders Ltd | Wholesale & retail | 2021 |
| MRP Global Services Ltd | Professional & scientific | 2016 |
| Mrpm Construction & Renovation Limited | Construction | 2015 |
| Mrpthree Limited | Energy | 2023 |
| MRS & MR Limited | Extraterritorial | 2021 |
| Mrtpharm Limited | Health & social care | 2023 |
| MRW Precision Engineering Limited | Professional & scientific | 2011 |
| MS Build Experts Ltd | Construction | 2025 |
| MS Financial Planning Ltd | Financial services | 2021 |
| MS Masonry Services Ltd | Construction | 2018 |
| MS Rendplast Ltd | Construction | 2013 |
| MS Solution Midland Limited | Wholesale & retail | 2022 |
| MS11 Ltd | Real estate | 2025 |
| MSA Care Services Ltd | Health & social care | 2019 |
| Msa-Hc Ltd | Financial services | 2025 |
| Msa-Ic Ltd | Real estate | 2025 |
| MSD Property Solutions Limited | Construction | 2025 |
| MSG1 Limited | Wholesale & retail | 2020 |
| MSH Holdings Limited | Professional & scientific | 2015 |
| MSJ Healthcare Limited | Wholesale & retail | 2013 |
| MSK Bar Ltd | Hospitality | 2021 |
| MSK Radiology Expert Limited | Health & social care | 2026 |
| MSK Transport Limited | Transport & logistics | 2007 |
| MSK1 Properties Ltd | Real estate | 2022 |
| MSL Motor Company Ltd | Wholesale & retail | 2026 |
| MSM Catering Services Ltd | Hospitality | 2025 |
| MSM Healthcare Solutions Limited | Health & social care | 2019 |
| Msolsce Photography Ltd | Professional & scientific | 2026 |
| MSP Global Solutions Ltd | Professional & scientific | 2019 |
| MSR Transport Ltd | Transport & logistics | 2023 |
| MSR Walsall Limited | Real estate | 2016 |
| MSS Mailorder Limited | Wholesale & retail | 2025 |
| MSS Recruitment Limited | Administrative & support | 2025 |
| Mstm Properties Ltd | Real estate | 2019 |
| Msuppal Ltd | Professional & scientific | 2014 |
| Msvr Limited | Wholesale & retail | 2022 |
| MT Globex Ltd | Transport & logistics | 2014 |
| MT Labs WM Ltd | Wholesale & retail | 2021 |
| MT Pharma Services Limited | Health & social care | 2026 |
| MTC Contracts Limited | Construction | 2014 |
| Mtds Limited | Professional & scientific | 2004 |
| MTK Housewares Limited | Manufacturing | 2017 |
| MTK IT Services Ltd | Information & communication | 2018 |
| MTM Locum Services Limited | Wholesale & retail | 2021 |
| MTR Auto Tyres Ltd | Wholesale & retail | 2023 |
| MTS Pharmco Ltd | Wholesale & retail | 2025 |
| MTT Chiropractic Ltd | Health & social care | 2022 |
| MU a Managements Ltd | Other services | 2018 |
| MU Holding Investments Limited | Professional & scientific | 2025 |
| MU Hospitality Ltd | Hospitality | 2022 |
| MUA Travel Services Limited | Transport & logistics | 2026 |
| Muaz Malik Ltd | Wholesale & retail | 2025 |
| Mucky Pups Dog Grooming Ltd | Agriculture & fishing | 2026 |
| Muerezen Ltd | Transport & logistics | 2024 |