| Midmech Ltd | Construction | 2019 |
| Midnight Munchies Birmingham Ltd | Wholesale & retail | 2019 |
| Midpath Ltd | Hospitality | 2025 |
| Midpoint Accommodation Limited | Hospitality | 2021 |
| Midpoint Serviced Accommodation LLP | | 2021 |
| Midpower Electrical Services Limited | Construction | 2023 |
| Midshire Asset Finance Limited | Financial services | 2019 |
| Mighty Light LED Ltd | Extraterritorial | 2013 |
| Mikba Hair and Beauty Ltd | Other services | 2020 |
| Mike Smith Training Ltd | Other services | 2020 |
| MILANO1899 Ltd | Hospitality | 2024 |
| Miles & O' Donnell Brickwork Ltd | Construction | 2015 |
| Miles & O'Donnell Property Ltd | Real estate | 2018 |
| Milestone Global (UK) Limited | Administrative & support | 2005 |
| Milestone Localization (UK) Limited | Administrative & support | 2021 |
| Milestone Planning Ltd | Professional & scientific | 2025 |
| Milk and Two Ltd | Hospitality | 2023 |
| Milktop Limited | Information & communication | 2013 |
| Mill Hollow Dorridge Management Company Limited | Households | 2011 |
| Mill Management (Stratford) Limited | Households | 1973 |
| Mill Mews Developments Limited | Construction | 2012 |
| Mill Mews Holdings Ltd | Financial services | 2024 |
| Mill Pool Consulting Limited | Professional & scientific | 2018 |
| Mill RI SC Limited | Financial services | 2020 |
| Millbrook Management (NO 2) Limited | Households | 1991 |
| Milleenya Property Management Ltd | Real estate | 2020 |
| Millennium Carpets Limited | Wholesale & retail | 1999 |
| Millgate Sheds Limited | Hospitality | 2023 |
| Millie-Rose Pooch Parlour Ltd | Other services | 2025 |
| Milliondollaracademy Ltd | Education | 2025 |
| Mills Electrical Limited | Construction | 2001 |
| Millstone Asset Management Ltd | Professional & scientific | 2024 |
| Milltown Construction Limited | Other services | 2017 |
| Millview Dent Limited | Health & social care | 2023 |
| Millwood Gardens Management Company Ltd | Real estate | 2024 |
| Millwood's Tankers Ltd | Construction | 2025 |
| Milner Landscapes and Construction Ltd | Administrative & support | 2017 |
| Milo Group Realty Limited | Real estate | 2025 |
| Miltown Developments LLP | | 2008 |
| Milvani Ltd | Real estate | 2026 |
| Milverton Property Investments Ltd | Real estate | 2017 |
| Milverton Terrace Management Company Limited | Households | 2004 |
| Minbage Soft Tech Ltd | Information & communication | 2024 |
| Mind DUO Limited | Health & social care | 2023 |
| Mind Space 247 Limited | Information & communication | 2021 |
| Mindful IT Limited | Information & communication | 2022 |
| Mindless Omission Ltd | Information & communication | 2017 |
| Mindspan Mentors Ltd | Education | 2025 |
| Mindwaze Ltd | Education | 2023 |
| Minelec Limited | Construction | 2020 |
| Minerva Health Limited | Professional & scientific | 2008 |
| Minihub Ltd | Wholesale & retail | 2025 |
| Minister for Every Occasion Ltd | Other services | 2013 |
| Ministry of Nikah Ltd | Professional & scientific | 2025 |
| Minortracts Builders Limited | Construction | 1961 |
| Minton Care (Tiverton) Limited | Construction | 2021 |
| Minton Investments (Industrial) Limited | Real estate | 1991 |
| Minton Tidbury Green Limited | Construction | 2023 |
| MIR Capital Ltd | Real estate | 2017 |
| Mira Education Ltd | Information & communication | 2018 |
| Mirabella's Events Ltd | Administrative & support | 2025 |
| Miraicore Ltd | Information & communication | 2025 |
| Mirfield Recruitment Limited | Administrative & support | 2013 |
| Mirfield Road (Solihull) Management Limited | Households | 2006 |
| Mirfield Services Limited | Professional & scientific | 2024 |
| Miss YOU Ltd | Real estate | 2023 |
| Mississippi Property Solutions Ltd | Real estate | 2026 |
| Mitaka House (Leamington Spa) Management Company Limited | Households | 2018 |
| Mitalby Limited | Real estate | 2015 |
| Mithraa Limited | Wholesale & retail | 2019 |
| Mithraa PVT Limited | Wholesale & retail | 2024 |
| MJ Adams Consultancy Limited | Administrative & support | 2012 |
| MJ Consultation Limited | Professional & scientific | 2017 |
| MJ Excavators Limited | Wholesale & retail | 2019 |
| MJ Fusion Limited | Professional & scientific | 2007 |
| MJ Hays Beauty Ltd | Other services | 2025 |
| MJ Matt James Ltd | Professional & scientific | 2023 |
| MJ Salon Solihull Ltd | Other services | 2021 |
| MJC Partnership Limited | Professional & scientific | 2007 |
| MJG Surveying Services Ltd | Financial services | 2016 |
| MJK Utilities Ltd | Construction | 2013 |
| Mjml Investments Limited | Financial services | 2021 |
| MJN Solutions Ltd | Information & communication | 2008 |
| MJP Global Procurement Solutions Ltd | Professional & scientific | 2021 |
| MJR Creative Limited | Professional & scientific | 2008 |
| MJS Red Solutions Ltd | Information & communication | 2015 |
| Mjsb IT Solutions Ltd | Information & communication | 2022 |
| MJW Contracts (Solihull) Limited | Professional & scientific | 2019 |
| MK Accessorize BT Limited | Manufacturing | 2025 |
| MK Administration Limited | Professional & scientific | 2025 |
| MK Attack Limited | Wholesale & retail | 2021 |
| MK Collective Group Limited | Arts & recreation | 2026 |
| MK Couriers Ltd | Transport & logistics | 2025 |
| MK Financial Ltd | Health & social care | 2023 |
| MK Healthhub Birmingham Limited | Arts & recreation | 2019 |
| MK Healthhub Holdings Limited | Financial services | 2019 |
| MK Healthhub Limited | Arts & recreation | 2009 |
| MK Heating & Plumbing Ltd | Construction | 2022 |
| MK PROPCO1 Limited | Real estate | 2020 |
| MK PROPCO2 Limited | Real estate | 2025 |