| MNU Solutions Ltd | Construction | 2020 |
| MO Action Group Ltd | Wholesale & retail | 2020 |
| MO Hussain Consultancy Limited | Transport & logistics | 2025 |
| Mobile Phone Extra Ltd | Other services | 2015 |
| Mobile Stuff Limited | Wholesale & retail | 2017 |
| Mockandberries Ltd | Wholesale & retail | 2024 |
| Moda London Ltd | Wholesale & retail | 2015 |
| Modeco Corp Limited | Hospitality | 2025 |
| Modena Transport Ltd | Transport & logistics | 2019 |
| Modern Building Solutions Ltd | Construction | 2025 |
| Mogeh Haid Supply Chain Solutions Ltd | Wholesale & retail | 2022 |
| Mojam Afrocaribbean Ltd | Wholesale & retail | 2020 |
| Mokola M. Limited | Wholesale & retail | 2025 |
| Momentera Management Ltd | Administrative & support | 2018 |
| Monarch Consultants Limited | Health & social care | 2009 |
| Monarch Healthcare (HB) Ltd | Health & social care | 2021 |
| Monarch Healthcare Limited | Health & social care | 1992 |
| Monarch Healthcare(Ferndene) Ltd | Health & social care | 2018 |
| Monique's Enterprises Ltd | Wholesale & retail | 2020 |
| Monisha.Locum Ltd | Health & social care | 2022 |
| Monster Mayhem Youth Club Limited | Education | 2020 |
| Monteith Scott Limited | Professional & scientific | 2000 |
| Montres Kler Ltd | Manufacturing | 2021 |
| Moon Thai Massage Theropist Ltd | Other services | 2024 |
| Moore Transport Limited | Transport & logistics | 2014 |
| Moran Construction Limited | Construction | 2022 |
| Morfinity Commercial Ltd | Financial services | 2025 |
| Morfinity Limited | Financial services | 2021 |
| Morgan Holistic Limited | Public administration | 2023 |
| Morganite Holdings Limited | Real estate | 2018 |
| Morris Upholstry Limited | Manufacturing | 2016 |
| Moseley Urban Village - 04 Ltd | Real estate | 2024 |
| Mossclear Ltd | Construction | 2022 |
| Mothership Projects C.I.C. | Education | 2018 |
| Mothi Tech Ltd | Information & communication | 2025 |
| Moto Travel Limited | Transport & logistics | 2019 |
| Motohub UK Ltd | Wholesale & retail | 2024 |
| MOTRU1 Ltd | Administrative & support | 2026 |
| Mount Nemrut Restaurant Limited | Hospitality | 2025 |
| Movement & Stillness CIC | Health & social care | 2025 |
| MP Furniture Repairs Ltd | Other services | 2017 |
| MP Transport WM Ltd | Transport & logistics | 2024 |
| MQ Powder Coating Ltd | Manufacturing | 2026 |
| MR Bubbles Limited | Administrative & support | 2009 |
| MR Grill Walsall Ltd | Hospitality | 2024 |
| MR Speedy Locksmith Ltd | Other services | 2026 |
| MR Tyreman (UK) Ltd | Other services | 2020 |
| MRK Motorhaus Ltd | Wholesale & retail | 2026 |
| MS Heating Services Ltd | Construction | 2020 |
| MSA Impex Limited | Wholesale & retail | 2022 |
| MSA Properties and Investments Ltd | Real estate | 2024 |
| Msgd Ltd | Real estate | 2021 |
| MSH Analytics Limited | Professional & scientific | 2024 |
| MSJ Logistics Limited | Transport & logistics | 2025 |
| MSP Gants Hill Ltd | Hospitality | 2025 |
| Msrta.M Limited | Wholesale & retail | 2025 |
| MSS Housing Ltd | Hospitality | 2024 |
| MSS Painting and Decorating Ltd. | Construction | 2025 |
| Msyl Ltd | Real estate | 2022 |
| MT Innovation & Enterprises Ltd | Real estate | 2024 |
| MTR Investment Properties Ltd | Real estate | 2024 |
| MTS - Chauffeur Service & Airport Transfers Limited | Transport & logistics | 2022 |
| Muhamet Ltd | Hospitality | 2026 |
| Muhsina Locum Services Limited | Health & social care | 2025 |
| Multi Lands Ltd | Wholesale & retail | 2022 |
| Multi Quick Powder Coating Limited | Manufacturing | 2007 |
| Multi Service JG Ltd. | Arts & recreation | 2005 |
| Multinetwork Limited | Information & communication | 2013 |
| Mummy's Corner Ltd | Hospitality | 2022 |
| Munch on the Move Ltd | Extraterritorial | 2024 |
| Mundi ASL Limited | Transport & logistics | 2024 |
| Murcuree Metrix Ltd | Professional & scientific | 2025 |
| Murry Cargo Ltd | Transport & logistics | 2025 |
| Muse Link Limited | Information & communication | 2020 |
| Mushtaq Legal Services Ltd | Professional & scientific | 2024 |
| Music Boutique Limited | Education | 2015 |
| Muskaan Estates Ltd | Real estate | 2006 |
| Muslim Funeral Services - Midlands Ltd | Other services | 2024 |
| Mustafa Supermarket Ltd | Wholesale & retail | 2018 |
| Mutlihub Goods Limited | Wholesale & retail | 2025 |
| MV Business Consulting Ltd | Administrative & support | 2015 |
| MVN Home ADD ONS & Security Services Ltd | Administrative & support | 2025 |
| MW Hearing Clinic Ltd | Health & social care | 2023 |
| My Care Birmingham Limited | Health & social care | 2019 |
| My Home Improvement Ltd | Construction | 2022 |
| My Mechanic Ltd | Extraterritorial | 2021 |
| My Textiles Limited | Wholesale & retail | 2021 |
| My Toppings Ltd | Hospitality | 2025 |
| Myben Verandas Ltd | Construction | 2022 |
| Myit Ltd | Arts & recreation | 2022 |
| Myriadmarketuk Ltd | Wholesale & retail | 2023 |
| MZ Consultancy Services Ltd | Professional & scientific | 2019 |
| MZI Pharm Ltd | Health & social care | 2012 |
| N D B Supplies Limited | Wholesale & retail | 2006 |
| N Holding (LON) Ltd | Professional & scientific | 2016 |
| N Kaur Limited | Wholesale & retail | 2020 |
| N Payroll Limited | Manufacturing | 2016 |
| N S Aulakh Properties Limited | Real estate | 2025 |
| N Wholesale Ltd | Wholesale & retail | 2016 |
| N&B Accountax Ltd | Professional & scientific | 2023 |