| MR Charcoal Ltd | Wholesale & retail | 2015 |
| MR Charcoal Wholesale Ltd | Wholesale & retail | 2026 |
| MR Chippyyy Limited | Hospitality | 2019 |
| MR Ladn Ltd | Information & communication | 2024 |
| MR Polish Ltd | Other services | 2016 |
| MR Proposal UK Ltd | Administrative & support | 2020 |
| MR Watch Gallery Ltd | Administrative & support | 2021 |
| MRC Business Consulting Ltd | Administrative & support | 2024 |
| MRJ Resourcing Limited | Administrative & support | 2026 |
| MRP Technology Limited | Administrative & support | 2006 |
| MRT Studio Limited | Manufacturing | 2005 |
| MS Landlord & Maintenance Ltd | Administrative & support | 2019 |
| MS North Star Limited | Financial services | 2019 |
| MS Production & Animation Limited | Information & communication | 2025 |
| MSD Tech Ltd | Information & communication | 2026 |
| Msht Properties UK Ltd | Real estate | 2018 |
| MSL (UK) Ltd | Administrative & support | 2014 |
| MSM Conventions Ltd | Construction | 2025 |
| MSM Hygiene Solutions Ltd | Administrative & support | 2014 |
| MSS Utilities Limited | Construction | 2024 |
| MT Car Valley Ltd | Wholesale & retail | 2024 |
| MT Lift Installation Ltd | Construction | 2011 |
| Mtbx Ltd | Information & communication | 2023 |
| MTC Surveying Limited | Professional & scientific | 2006 |
| MTM Development Ltd | Other services | 2022 |
| Mukajmedics Ltd | Health & social care | 2022 |
| Mulalley & Co. Limited | Construction | 1980 |
| Mulalley Operations Limited | Professional & scientific | 2018 |
| Multiplex IT Supports Limited | Information & communication | 2015 |
| Mum's Home Ltd | Real estate | 2019 |
| Munchie Combos Ltd | Professional & scientific | 2026 |
| Muramasa Industries Limited | Administrative & support | 2003 |
| Murphy Electrical Ltd | Administrative & support | 2017 |
| Music Station Ltd | Education | 2012 |
| Musicboxcompany Limited | Manufacturing | 2021 |
| Muslim Women's Advisory Council CIC | Health & social care | 2019 |
| Muzalaya Group PVT Ltd | Real estate | 2025 |
| Muzo Sound Limited | Other services | 2016 |
| Mvlt Limited | Construction | 2023 |
| MVN Block Management Ltd | Real estate | 2022 |
| MVP Wholesale Limited | Wholesale & retail | 2025 |
| MWM Sports Academy Limited | Wholesale & retail | 2015 |
| Mxgxpert Limited | Information & communication | 2010 |
| My Active Practice CIC | Other services | 2018 |
| My Clove Restaurant Ltd | Hospitality | 2026 |
| My Design Co (Global) Ltd | Manufacturing | 2021 |
| My Design Collections Limited | Manufacturing | 2013 |
| My Design Company (UK) Limited | Administrative & support | 2003 |
| My Food Service Ltd | Wholesale & retail | 2023 |
| My Holdings Limited | Extraterritorial | 2017 |
| My Holiday Retreat Ltd | Hospitality | 2026 |
| My Luxury Tour Ltd | Administrative & support | 2018 |
| My Own Accountant Limited | Real estate | 2011 |
| My Own Security Expert Ltd | Administrative & support | 2026 |
| My Pharma Group 1 Ltd | Wholesale & retail | 2024 |
| MYA Lois Carriere-Amoo Ltd | Extraterritorial | 2022 |
| MYD Studio London Limited | Professional & scientific | 2020 |
| Myla's Cafe Ltd | Hospitality | 2025 |
| Myles Residential Limited | Real estate | 2018 |
| Mylesit Limited | Information & communication | 2013 |
| Mylkman Ltd | Manufacturing | 2017 |
| Myrene Holdings Limited | Professional & scientific | 2016 |
| Myrene Signs Limited | Manufacturing | 1995 |
| Mystical Alchemy Limited | Hospitality | 2024 |
| Mytton Ltd | Administrative & support | 2014 |
| Mytwentytwo Ltd | Wholesale & retail | 2021 |
| MZ Auto Parts Ltd | Wholesale & retail | 2025 |
| MZ Systems Ltd | Information & communication | 2025 |
| N I & M Ltd | Wholesale & retail | 2019 |
| N&C Digital Limited | Administrative & support | 2014 |
| N. Boulton Limited | Arts & recreation | 2015 |
| N15 Films Limited | Information & communication | 2022 |
| NA - Cleanz Ltd | Administrative & support | 2022 |
| Naben Limited | Other services | 2003 |
| Nabilius Management Ltd | Real estate | 2021 |
| Nabilius Properties Ltd | Real estate | 2020 |
| Nachal Limited | Other services | 2019 |
| Nailslaza Ltd | Other services | 2026 |
| Nair Gynaecology Ltd | Health & social care | 2025 |
| NAJ Creative Ltd | Arts & recreation | 2019 |
| Nakum Ltd | Information & communication | 2016 |
| Nalimu Limited | Health & social care | 2013 |
| Nannie Annies Day Care Limited | Education | 2017 |
| Nannie Annies Holdings Limited | Financial services | 2025 |
| Nannie Annies Properties Limited | Real estate | 2022 |
| Nanotos Limited | Wholesale & retail | 2023 |
| Nappeez Ltd | Wholesale & retail | 2010 |
| Napt Property Investments Limited | Real estate | 2017 |
| NAR Turkish Grill Ltd | Hospitality | 2026 |
| Nasd Limited | Real estate | 2013 |
| Nash Distribution Limited | Extraterritorial | 2022 |
| Natasha Sandhu Ltd | Administrative & support | 2018 |
| Natio Recruitment Limited | Administrative & support | 2015 |
| National Skills Agency Limited | Administrative & support | 2017 |
| Nationwide Glazers Limited | Construction | 2024 |
| Natural Banyan Ltd | Arts & recreation | 2024 |
| Natural Progression Infinity Ltd | Wholesale & retail | 2014 |
| Natural Ventilation Controls Holdings Limited | Administrative & support | 2018 |
| Natural Ventilation Controls Limited | Administrative & support | 2016 |
| Natures Drop Limited | Hospitality | 2025 |