| Movesure Movers Ltd | Transport & logistics | 2026 |
| Movid Ltd | Transport & logistics | 2026 |
| Moving U2 Ltd | Transport & logistics | 2020 |
| Movit UK Limited | Professional & scientific | 2010 |
| Mowberry Close and Malet Close (Management) Limited | Professional & scientific | 1977 |
| Moxham Books Ltd | Wholesale & retail | 2011 |
| Mozo Ltd. | Hospitality | 2025 |
| Mozol Ltd | Wholesale & retail | 2025 |
| Mozztec IT Ltd | Information & communication | 2013 |
| MPA Support Services Ltd | Information & communication | 2022 |
| MPG Roofing Limited | Construction | 2002 |
| MPM Housing Limited | Professional & scientific | 1998 |
| MPS Housing Limited | Administrative & support | 2018 |
| MPW Mechanical Services Ltd | Construction | 2018 |
| MPY Property Services Ltd | Construction | 2023 |
| MR and MRS P PUB Services Ltd | Arts & recreation | 2020 |
| MR B Next Barber Shop Limited | Other services | 2017 |
| MR Bonds Tonic Limited | Manufacturing | 2016 |
| MR CB Property Solutions Limited | Real estate | 2018 |
| MR M H Jaffer & Co Limited | Wholesale & retail | 2008 |
| Mr.Xxl Auto Garage Ltd | Wholesale & retail | 2026 |
| MRB Fire Safety Services Ltd | Public administration | 2023 |
| Mrbeardstone Limited | Information & communication | 2024 |
| Mrcb Homes Ltd | Real estate | 2020 |
| Mrcb Property Limited | Real estate | 2023 |
| Mritsa Ltd | Real estate | 2023 |
| MRK Estates Limited | Households | 2019 |
| MRS Melton's Smoke Shack Ltd | Wholesale & retail | 2024 |
| MRT (Europe) Limited | Administrative & support | 2001 |
| Mrthomaschapman Ltd | Health & social care | 2016 |
| MRU Property Ltd | Real estate | 2025 |
| MS Industry UK Ltd | Wholesale & retail | 2022 |
| MS LN Electrical Ltd | Construction | 2012 |
| MS2 Holdings Limited | Financial services | 2022 |
| MSB Autos Ltd | Wholesale & retail | 2017 |
| MSD Technologies Ltd | Administrative & support | 2024 |
| MSK Recruitment Limited | Administrative & support | 2022 |
| Mstarling Limited | Financial services | 2020 |
| MSW Property Management Ltd | Real estate | 2024 |
| MT Carpentry and Construction Ltd | Construction | 2026 |
| MT. Moon Tattoo Ltd | Other services | 2019 |
| Mtci Limited | Professional & scientific | 2019 |
| Mtfx Online Limited | Arts & recreation | 2001 |
| MTN Property Solutions Group Ltd. | Construction | 2024 |
| Muaaz Ltd | Wholesale & retail | 2025 |
| Muchacho Gloucester Ltd | Hospitality | 2025 |
| Muhammad Tech Solution Ltd | Wholesale & retail | 2026 |
| MUK a G'S Ltd | Manufacturing | 2023 |
| Mukietz Healthcare Limited | Health & social care | 2015 |
| Mukoro Investments Ltd | Financial services | 2025 |
| Mulberry Building & Security Services Limited | Administrative & support | 2005 |
| Mulganic Ltd | Wholesale & retail | 2026 |
| Mull Holdings Ltd | Professional & scientific | 2022 |
| Mulla Engineering Services Limited | Professional & scientific | 2025 |
| Mullaney Capital Limited | Financial services | 2023 |
| Mullaney Care Limited | Health & social care | 2025 |
| Mullaney Construction & Property Services Limited | Construction | 2022 |
| Mullaney Electrical Limited | Construction | 2023 |
| Mullaney Group Limited | Financial services | 2023 |
| Mullaney Living Limited | Real estate | 2024 |
| Mullerz Ltd | Wholesale & retail | 2025 |
| Mullis & Sons Ltd | Construction | 2025 |
| Multilink Management Care Ltd | Health & social care | 2016 |
| Multipest Limited | Administrative & support | 2005 |
| Multiple Skillz Ltd | Information & communication | 2021 |
| Mumy's Juicy Spice Ltd | Hospitality | 2025 |
| Munchies Stonehouse Limited | Wholesale & retail | 2023 |
| Muniparts Ltd | Extraterritorial | 2026 |
| Munrow Ltd | Real estate | 2026 |
| Murdock & Wasley Estate Agents Ltd | Real estate | 2020 |
| Murdock & Wasley Holdings Ltd | Real estate | 2021 |
| Murstack Limited | Wholesale & retail | 2024 |
| Murukandy Ltd | Wholesale & retail | 2017 |
| Musthud Design Ltd | Manufacturing | 2024 |
| Mustoe Management Ltd | Arts & recreation | 2012 |
| Mutual Benefit Care Limited | Health & social care | 2007 |
| Muwonigroup Ltd | Transport & logistics | 2019 |
| Muzzle Patch (Managers) Limited | Households | 1973 |
| MV Acquisition Limited | Real estate | 2021 |
| MV Selection Ltd | Wholesale & retail | 2025 |
| MVG Logistics Services Ltd | Transport & logistics | 2016 |
| MVM Ventures Ltd | Wholesale & retail | 2026 |
| MW Carpentry and Construction Ltd | Construction | 2020 |
| MW Golf Academy Ltd | Education | 2014 |
| MW Motorsport Ltd | Wholesale & retail | 2024 |
| MW People Solutions Ltd | Administrative & support | 2022 |
| MW Properties and Investments Ltd | Real estate | 2025 |
| Mwbuildingconservation Limited | Construction | 2013 |
| MWK Apparel Ltd | Wholesale & retail | 2025 |
| MWL Holdings Ltd | Financial services | 2023 |
| MXM Investments Ltd | Real estate | 2026 |
| My Bazaar Ltd | Wholesale & retail | 2025 |
| My Bubu Ltd | Real estate | 2025 |
| My Business Partner Limited | Professional & scientific | 2016 |
| My Care Companion Ltd | Information & communication | 2026 |
| My Dream Experience Limited | Administrative & support | 2017 |
| My Education Appeal Ltd | Education | 2025 |
| My Gift My Career CIC | Education | 2026 |
| My Lifestyle Changes Ltd | Wholesale & retail | 2025 |
| My Maintenance Limited | Construction | 2023 |