| Mogo (UK) Limited | Extraterritorial | 1995 |
| Mohawk Engineering Ltd | Professional & scientific | 2025 |
| Mohith Global Limited | Other services | 2024 |
| Molecusan UK Limited | Manufacturing | 2024 |
| Momo Mandap Limited | Hospitality | 2024 |
| Momo Station Ltd | Hospitality | 2014 |
| Momo Suppliers Ltd | Wholesale & retail | 2017 |
| Monk Conveyors Limited | Manufacturing | 2000 |
| Montale Limited | Wholesale & retail | 1998 |
| Monza Design Furniture Agency Ltd | Wholesale & retail | 2025 |
| MOO ROO Design Ltd | Information & communication | 2009 |
| Moonlit Productions Ltd | Administrative & support | 2026 |
| Morden Builders Ltd | Construction | 2014 |
| More for Your Money Mortgages Ltd | Professional & scientific | 2007 |
| More Therapy Limited | Health & social care | 2015 |
| Morrissey Elite Global Group Ltd | Transport & logistics | 2019 |
| Mossman Media Ltd | Information & communication | 2026 |
| MOT Reminders Limited | Wholesale & retail | 2021 |
| Mote DAI KO Restaurant Ltd | Hospitality | 2025 |
| Motest Holdings Limited | Financial services | 2022 |
| Motest Property (Camberley) Limited | Real estate | 2022 |
| Motest Property (Hemel Hempstead) Limited | Real estate | 2022 |
| Motest Property (Lewes) Limited | Real estate | 2023 |
| Motest Property (Reading) Limited | Real estate | 2022 |
| Motest Southern Limited | Wholesale & retail | 2017 |
| Mother Teresa Catholic Academy Trust | Education | 2011 |
| Motoxmad Ltd | Wholesale & retail | 2023 |
| Mount Everest Thakali Kitchen Ltd | Hospitality | 2026 |
| Mousetail Web Services Limited | Information & communication | 2013 |
| Move With Nicol Limited | Health & social care | 2026 |
| MPE Brickwork & Construction Ltd | Construction | 2019 |
| MPF Limited | Extraterritorial | 1988 |
| MPL Consultants Limited | Information & communication | 2025 |
| MR Electric Wholesale Limited | Professional & scientific | 1996 |
| MR. Wing & Co Limited | Hospitality | 1986 |
| Mr.Theesh Restaurant Limited | Hospitality | 2025 |
| MS Union Street Ltd | Other services | 2023 |
| MS Way Logistics Ltd | Transport & logistics | 2024 |
| MSD Commercial Ltd | Water & waste | 2017 |
| MSH Property Services Ltd | Real estate | 2024 |
| MSI Construct Ltd | Construction | 2026 |
| Mssk Corporate Consultancy (UK) Limited | Professional & scientific | 2022 |
| MUC Services Ltd | Administrative & support | 2023 |
| Multiple Operations Limited | Administrative & support | 2019 |
| Muna Hair and Beauty PVT Ltd | Other services | 2024 |
| Muna Property Ltd | Real estate | 2026 |
| Muna Unisex Hair & Beauty Salon Ltd | Other services | 2015 |
| Munaza Tasneem Ltd. | Real estate | 2015 |
| Murdock Plumbing and Maintenance Ltd | Construction | 2026 |
| Music Portal Ltd | Extraterritorial | 2006 |
| Mustard Inc. Limited | Wholesale & retail | 2025 |
| My Mobile Mechanic Ltd | Wholesale & retail | 2015 |
| My Mortgage Matters Limited | Financial services | 2017 |
| My Property Planner Ltd | Wholesale & retail | 2025 |
| MYF Training Limited | Education | 2002 |
| Mylegacymatters Ltd | Professional & scientific | 2018 |
| Myra Consultancy Limited | Professional & scientific | 2024 |
| Myriad Defence Ltd | Information & communication | 2023 |
| Mystri Limited | Other services | 2024 |
| Mystringer Ltd | Wholesale & retail | 2020 |
| N&N Investment Properties Limited | Real estate | 2023 |
| N&S Art Ltd | Arts & recreation | 2025 |
| NA Kebabish Limited | Hospitality | 2026 |
| NA Pizza Centre Limited | Hospitality | 2025 |
| Nabin & Nabin Ltd | Manufacturing | 2019 |
| Nadya Hickey Consulting Limited | Professional & scientific | 2023 |
| Naga House Limited | Hospitality | 2025 |
| Nagu Restaurant Limited | Hospitality | 2021 |
| Nails an Nails 59-61 Ltd | Other services | 2026 |
| Nails an Nails Ltd | Other services | 2025 |
| Nameimage Limited | Information & communication | 1990 |
| Namis Capital Ltd | Real estate | 2018 |
| Namis Development Ltd | Construction | 2016 |
| Namu & Sons PVT Ltd | Hospitality | 2024 |
| Namuna Aesthetic Korean Skincare Ltd | Other services | 2025 |
| Namuna Beauty Parlour Ltd | Other services | 2017 |
| Nana Properties UK Ltd | Real estate | 2024 |
| Nandi Express Ltd | Wholesale & retail | 2026 |
| Nanglo Bites Ltd | Hospitality | 2024 |
| Naome Murefu Ltd | Health & social care | 2011 |
| Narlyn Discion Limited | Health & social care | 2015 |
| Natalie Sudnik Limited | Wholesale & retail | 2021 |
| Nathan and Sons Landscaping Ltd | Administrative & support | 2024 |
| Nathaniel Cross Development Limited | Information & communication | 2011 |
| National Caravan Council Limited | Other services | 1953 |
| National Secure Ltd | Administrative & support | 2024 |
| Nationwide Cleaning Limited | Arts & recreation | 1990 |
| Nationwide Fire Door Services Ltd | Construction | 2020 |
| NAZ Hand Car Wash Ltd | Other services | 2019 |
| NCC Cris Limited | Information & communication | 2013 |
| NCC Events Limited | Administrative & support | 2010 |
| NDV Estates Ltd | Real estate | 2015 |
| Neapolis Terracotta Limited | Wholesale & retail | 2013 |
| Neater Heat Ltd | Construction | 2016 |
| Nebryx Blue Lotus Ltd | Wholesale & retail | 2025 |
| Nefin CIC | Wholesale & retail | 2025 |
| Nepal FED of Indigenous UK Limited | Health & social care | 2025 |
| Nepal Film SOC UK Ltd | Information & communication | 2020 |
| Nepal House PVT Limited | Hospitality | 2024 |
| Nepalese Business Directory Ltd | Professional & scientific | 2022 |