| MR Bear's Media Ltd | Professional & scientific | 2021 |
| MR Invest NW Limited | Real estate | 2022 |
| MR Investa Ltd | Real estate | 2020 |
| MR Services Real Estate Ltd | Other services | 2021 |
| MR Thomas's Cafe Ltd | Hospitality | 2018 |
| MR. D Autocare Services Ltd | Administrative & support | 2026 |
| Mrbl Limited | Financial services | 2012 |
| Mrmsuk Ltd | Wholesale & retail | 2020 |
| MRS. A'S Kitchen Ltd | Hospitality | 2019 |
| MRW Estates Ltd | Real estate | 2026 |
| MS Community Trust | Other services | 2023 |
| MS Consulting Services Ltd | Information & communication | 2026 |
| MS Creative Hospitality Ltd | Wholesale & retail | 2025 |
| MS Flavors Limited | Wholesale & retail | 2025 |
| MS Kids Limited | Wholesale & retail | 2015 |
| MS Lending SPV 1 Limited | Financial services | 2022 |
| MS Lending SPV 2 Limited | Financial services | 2022 |
| MS Lending SPV 3 Limited | Financial services | 2022 |
| MS Lending SPV 4 Limited | Financial services | 2026 |
| MS Lending SPV 5 Limited | Financial services | 2026 |
| MS Lending SPV 6 Limited | Financial services | 2026 |
| MS Move ME Ltd | Transport & logistics | 2025 |
| MS Pharmaflex Ltd | Wholesale & retail | 2025 |
| MS Souvenirs & Gifts Ltd | Wholesale & retail | 2025 |
| MS Superstore Limited | Wholesale & retail | 2018 |
| MS Textile Limited | Wholesale & retail | 2025 |
| MSD Propertiesestates Ltd | Real estate | 2026 |
| MSH Marine Ltd | Administrative & support | 2018 |
| MSI Ceilings Ltd | Construction | 2020 |
| MSL Independent Financial Advisers Limited | Financial services | 2004 |
| MSL Sport Consultant Ltd | Arts & recreation | 2020 |
| MSM Logistics and General Ltd | Transport & logistics | 2018 |
| Msplattitude Ltd | Other services | 2022 |
| Mssr Solutions Limited | Professional & scientific | 2025 |
| MSY Investments Limited | Real estate | 2017 |
| MT Boxing & Fitness Ltd | Education | 2023 |
| MT Health Care Services Ltd | Health & social care | 2015 |
| MT Nanny and Governess Services Limited | Education | 2020 |
| MT Ptoperty Limited | Real estate | 2024 |
| MTE Office Ltd | Information & communication | 2019 |
| MTK Estates Ltd | Real estate | 2024 |
| MTN Caphe Ltd | Hospitality | 2025 |
| Mtrc (Trustees) Limited | Arts & recreation | 2016 |
| Mubish Limited | Wholesale & retail | 2023 |
| Mucklevision Limited | Information & communication | 2019 |
| Muffty Developments Limited | Construction | 2020 |
| Muhammad Maaz Ijaz Ltd | Wholesale & retail | 2025 |
| Mukkaram and Company Limited | Wholesale & retail | 2022 |
| Mulbery Design Studio Ltd | Professional & scientific | 2024 |
| Mulligan Limited | Administrative & support | 2006 |
| Munchyhub Limited | Manufacturing | 2020 |
| Munif Healthcare Limited | Health & social care | 2026 |
| Munif Management Limited | Real estate | 2022 |
| Munjal Limited | Wholesale & retail | 2025 |
| Munta Property Limited | Real estate | 2019 |
| Murad's Group Ltd | Other services | 2016 |
| Murphy Waldron Estates Limited | Real estate | 2017 |
| Murray Point Ltd | Real estate | 2025 |
| Muscle Corp Limited | Manufacturing | 2021 |
| Muscroft Engineering Limited | Professional & scientific | 2015 |
| Mushtaqq Ltd | Wholesale & retail | 2022 |
| Mushy Art Limited | Arts & recreation | 2019 |
| Music Action International Ltd | Health & social care | 2009 |
| Music House Family Limited | Information & communication | 2012 |
| Music Skylink Ltd | Arts & recreation | 2023 |
| Music Talks Limited | Arts & recreation | 2025 |
| Musicsource Limited | Education | 2024 |
| Muslim Hearts Limited | Information & communication | 2025 |
| Mustapha Holding Company Ltd. | Financial services | 2018 |
| Mvdc Kier Holdco 1 LLP | | 2023 |
| Mvdc Kier Holdco 2 LLP | | 2023 |
| Mvlo Limited | Administrative & support | 2026 |
| MW Recovery Services Ltd | Transport & logistics | 2021 |
| MW Strategy Limited | Professional & scientific | 2025 |
| My Chair Online Ltd | Manufacturing | 2021 |
| My Cosmetic Clinic Limited | Health & social care | 2018 |
| My Creative SAF Ltd | Health & social care | 2022 |
| My Dear Bubble Tea Ltd | Wholesale & retail | 2022 |
| My Future Planning Limited | Administrative & support | 2018 |
| My Lean Shakes Ltd | Manufacturing | 2026 |
| My Little Stories Ltd | Wholesale & retail | 2026 |
| My Little Sunshine Ltd | Health & social care | 2017 |
| My Media World Ltd | Professional & scientific | 2020 |
| My Opportunity Group Limited | Administrative & support | 2018 |
| My PAY CIS Ltd | Construction | 2025 |
| My Project Interview Limited | Education | 2025 |
| My Store Manchester Ltd | Information & communication | 2018 |
| My.Hair&Co Ltd | Other services | 2025 |
| Mydas Education and Training (UK) Consultancy Ltd | Education | 2020 |
| MYG Management Team Ltd | Real estate | 2019 |
| MYG Sheff Ltd | Households | 2025 |
| Myguru Global Limited | Administrative & support | 2022 |
| Myhandy Ltd | Construction | 2022 |
| Myhome Mortgages Limited | Financial services | 2025 |
| Myleson Group Ltd | Wholesale & retail | 2025 |
| Myliko International (Wines) Ltd. | Wholesale & retail | 1991 |
| Mylite Management Ltd | Real estate | 2025 |
| Mylt Ltd | Real estate | 2021 |
| Myrmidon IT Ltd | Information & communication | 2025 |
| Myroban Ltd | Construction | 2026 |