| Lomond Group Ltd | Financial services | 2020 |
| Long Byre Investments Limited | Administrative & support | 2011 |
| Lost Panda Properties Ltd | Real estate | 2022 |
| Lotus Care PVT Limited | Health & social care | 2017 |
| Lotus Investment Property Limited | Real estate | 2020 |
| Louis Courtney Photography Ltd | Professional & scientific | 2017 |
| Love Your Hair (Redditch) Limited | Other services | 2016 |
| Lowi Limited | Information & communication | 2005 |
| Lp(A) Education and Research Forum | Professional & scientific | 2023 |
| Lucellas Solutions Ltd | Information & communication | 2023 |
| Lunarvalenest Ltd | Transport & logistics | 2019 |
| Lydex Solutions Ltd | Information & communication | 2026 |
| Lyndon Court Limited | Real estate | 1981 |
| Lyndon Kidzone Limited | Health & social care | 2019 |
| M & H Network & Cabling Ltd | Construction | 2021 |
| M Mansell Engineering Ltd | Professional & scientific | 2011 |
| M V P Davies Limited | Real estate | 2026 |
| M-Tec ES Ltd | Administrative & support | 2026 |
| MA Maison Property Ltd | Real estate | 2025 |
| Mactaverns Limited | Hospitality | 2017 |
| Madoc Ltd | Professional & scientific | 2014 |
| Magna Consulting Ltd | Real estate | 2023 |
| Mahoney Brickworks Ltd | Construction | 2018 |
| Maiia Ltd | Administrative & support | 2011 |
| Make Noise Pro Audio Ltd | Wholesale & retail | 2020 |
| MAL Consultancy Ltd | Professional & scientific | 2022 |
| Malcolm Nicholls (Holdings) Limited | Financial services | 2017 |
| Manflowers Ltd | Wholesale & retail | 2013 |
| Manik Ventures Limited | Professional & scientific | 2013 |
| Manutex Ltd | Agriculture & fishing | 2025 |
| Maple (262) Limited | Administrative & support | 2005 |
| Maple Court (Shooters Hill SE18) Limited | Other services | 2010 |
| Marchella Ltd | Wholesale & retail | 2023 |
| Marcus David Emerson Limited | Extraterritorial | 2025 |
| Marigolds Domestic Services Limited | Administrative & support | 2016 |
| Marla (Alcester) Limited | Extraterritorial | 1953 |
| Marla Tube Fittings Limited | Wholesale & retail | 1956 |
| Marmillow Limited | Extraterritorial | 2017 |
| Martin-Davis Stationery Limited | | 1987 |
| Marvel Windows Limited | Construction | 2014 |
| Matchmakers Dating Limited | Other services | 2011 |
| Mateita Limited | Transport & logistics | 2023 |
| Maudslay Mart CIC | Wholesale & retail | 2024 |
| Mavericks Hair Ltd | Other services | 2011 |
| Maxwell 247 Limited | Information & communication | 2017 |
| MB Builders (Midlands) Limited | Construction | 2019 |
| MC Furniture Makers Limited | Manufacturing | 2019 |
| Mcgregor & Ross Ltd | Transport & logistics | 2019 |
| Mcjw Limited | Financial services | 2016 |
| Mcpherson Rose Consulting Ltd | Professional & scientific | 2025 |
| Mcpherson Rose Developments Ltd | Real estate | 2022 |
| Mcpherson Rose Old Dairy Limited | Real estate | 2023 |
| MD Holt Ltd | Administrative & support | 2022 |
| Meaden INT Ltd | Real estate | 2016 |
| Meat Sales (UK) Limited | Wholesale & retail | 2018 |
| Medtech Consulting Ltd | Professional & scientific | 2019 |
| MEI Youth Services CIC | Health & social care | 2025 |
| MEJ Engineering Consultants Limited | Professional & scientific | 2025 |
| Melcius Ltd | Administrative & support | 2019 |
| Mercatusretail Ltd | Wholesale & retail | 2024 |
| Merem Limited | Real estate | 2015 |
| MFT Properties Limited | Construction | 2006 |
| MI Workshops Limited | Manufacturing | 2021 |
| MIB Autotecniq Ltd | Professional & scientific | 2009 |
| Middle England Farm Ltd | Agriculture & fishing | 2021 |
| Middleton Homes Consultancy Ltd | Construction | 2024 |
| Midland & Continental Investments Limited | Real estate | 1984 |
| Midland Boiler Services Ltd | Construction | 2025 |
| Midland Mustangs Limited | Wholesale & retail | 2017 |
| Midlands Lighting Solutions Ltd. | Professional & scientific | 2016 |
| Midshires Care Holdings Limited | Professional & scientific | 2011 |
| Midshires Care Limited | Health & social care | 2000 |
| Milestone Investments (UK) Limited | Administrative & support | 2005 |
| Mill Lane Users Limited | Households | 2010 |
| Mill Pond House Limited | Real estate | 2014 |
| Mill Street Lettings Limited | Real estate | 2025 |
| Miller Hughes Construction Ltd | Construction | 2002 |
| Miller Hughes Partnership Limited | Real estate | 2003 |
| Milporo Ltd | Wholesale & retail | 2019 |
| Mise EN Plan Ltd | Professional & scientific | 2025 |
| Mission Energy Limited | Extraterritorial | 2017 |
| Mission Heru Ltd | Professional & scientific | 2011 |
| Mission Planet Foundation CIC | Information & communication | 2025 |
| MJB Consultancy (UK) Limited | Professional & scientific | 2013 |
| Mjgcr Emerson Limited | Extraterritorial | 2025 |
| Mjvf Consulting Ltd | Professional & scientific | 2022 |
| MKO Resourcing Limited | Administrative & support | 2011 |
| MNA Barber Ltd | Professional & scientific | 2017 |
| MNX Healthcare Limited | Health & social care | 2016 |
| Mode Hoists UK Ltd | Wholesale & retail | 2026 |
| Molloy & Co Associates Ltd | Professional & scientific | 2023 |
| Molloy & Co Holdings Limited | Financial services | 2025 |
| Mona’S Home Cooking Ltd | Hospitality | 2018 |
| Montierco Ltd | Health & social care | 2023 |
| Moonrisesports Ltd | Education | 2020 |
| Moore Elevation Scaffolding Ltd | Construction | 2025 |
| Mopheads Group Limited | Administrative & support | 2019 |
| Mopheads Solihull Limited | Administrative & support | 2020 |
| More Global Marketing Ltd | Professional & scientific | 2023 |
| Mormentum Consulting Ltd | Professional & scientific | 2026 |