| Muscatech Limited | Information & communication | 2019 |
| Museling Ltd | Information & communication | 2026 |
| Museophile Limited | Information & communication | 2002 |
| Museum Selection Limited | Wholesale & retail | 2003 |
| Music and Letters Trust | Education | 1956 |
| Music at Oxford | Arts & recreation | 1984 |
| Must Adapt Renovate Design Ltd. | Construction | 2025 |
| Musterlin Group PLC | | 1981 |
| Mutcare Limited | Health & social care | 2015 |
| Muzim Ltd. | Education | 2017 |
| Muzulu Limited | Information & communication | 2018 |
| MV Recovery Ltd | Hospitality | 2022 |
| MV Scaffolding & Scaffolding Safety Inspections Limited | Construction | 2009 |
| MVC Focused Flooring Ltd | Construction | 2025 |
| Mven Limited | Professional & scientific | 2009 |
| MVS Taxis Ltd | Transport & logistics | 2020 |
| Mxsoft Ltd | Information & communication | 2025 |
| My Barbers Ltd | Other services | 2024 |
| My Barbers Oxon Ltd | Other services | 2021 |
| My Blue Pencil Limited | Professional & scientific | 2009 |
| My Coaching Place Ltd | Information & communication | 2022 |
| My Fitness Class Ltd | Information & communication | 2018 |
| My IVA Limited | Professional & scientific | 2025 |
| My Online Seller Ltd | Wholesale & retail | 2025 |
| My Oxford Haven Ltd | Professional & scientific | 2025 |
| My Property World Limited | Real estate | 2024 |
| My. KUY Limited | Real estate | 2019 |
| My.Am & Co Limited | Real estate | 2019 |
| MY1PLUMBER Ltd | Construction | 2020 |
| MY1PROPERTYMANAGEMENT Limited | Real estate | 2023 |
| MY1PROPETYSOLUTIONS Ltd | Construction | 2023 |
| MYA Excavation Ltd | Construction | 2025 |
| Mybeautifulbody Ltd | Wholesale & retail | 2024 |
| Mycofeast Ltd | Professional & scientific | 2023 |
| Mycrystal Homes Ltd | Real estate | 2024 |
| MYFOOD365 Ltd | Wholesale & retail | 2023 |
| Myko Limited | Wholesale & retail | 2015 |
| Mylight Care UK Ltd | Health & social care | 2019 |
| Myma Property Holdings Ltd | Real estate | 2025 |
| Mymaths Limited | Information & communication | 2009 |
| Myocd Ltd | Wholesale & retail | 2025 |
| Myonlineschool Ltd | Education | 2014 |
| Mypeoplemanager Holdings Limited | Financial services | 2019 |
| Mypeoplemanager Limited | Information & communication | 2014 |
| Myray Limited | Other services | 2018 |
| Myriad Care Ltd | Health & social care | 2021 |
| Myriad Editions Limited | Information & communication | 1993 |
| Myvision Oxfordshire Ltd | Health & social care | 2010 |
| Mzak Limited | Health & social care | 2015 |
| N & F Langley Court Limited | Real estate | 2020 |
| N & F Properties and Developments Ltd | Real estate | 2021 |
| N Ahmadouk Medical Consultancy Limited | Health & social care | 2015 |
| N Glover Ltd | Health & social care | 2015 |
| N Squared Group Limited | Information & communication | 2023 |
| N. & S. Connolly Limited | Construction | 2007 |
| N2U Enterprises Ltd | Wholesale & retail | 2023 |
| N8 Express Ltd | Wholesale & retail | 2022 |
| Nabiy Limited | Health & social care | 2018 |
| Nabs Services Ltd | Health & social care | 2025 |
| Nacl Consulting Limited | Information & communication | 2016 |
| Nacmedical Ltd | Health & social care | 2023 |
| Nada & A.M.Y Ltd. | Other services | 2017 |
| Nadiflick Limited | Health & social care | 2024 |
| Nagis London Ltd | Wholesale & retail | 2025 |
| Naik & Co. Ltd | Real estate | 2026 |
| Nair Asset Management Ltd | Financial services | 2024 |
| NAJ MAS Property Investment Ltd | Real estate | 2025 |
| Najar Place Ltd | Hospitality | 2025 |
| Najib Ltd | Transport & logistics | 2020 |
| Nakn Limited | Real estate | 2020 |
| Nalder and Nalder Limited | Real estate | 1866 |
| Nalder Estate (East Challow) Management Company Limited | Households | 2014 |
| Nali Fitness Ltd | Arts & recreation | 2025 |
| Namaste Gurkha Kitchen Ltd | Hospitality | 2025 |
| Namaste Kitchen PVT Ltd | Hospitality | 2024 |
| Nami Properties Ltd | Real estate | 2018 |
| Namicon Ltd | Wholesale & retail | 2024 |
| Nanarose Ltd | Hospitality | 2026 |
| Nanolyse Technologies Limited | Professional & scientific | 2020 |
| Nanometrix Ltd | Information & communication | 2022 |
| Nansen Peak Limited | Real estate | 2021 |
| Naomi Swain Wellspace Ltd | Other services | 2025 |
| Napolitan Supplies Limited | Construction | 2019 |
| Nari Collective Ltd | Professional & scientific | 2026 |
| Nascent Leaf Limited | Wholesale & retail | 2022 |
| Nascot Homes Limited | Construction | 2013 |
| Naseem Property Limited | Real estate | 2018 |
| Nassor Ltd | Transport & logistics | 2025 |
| Natcapacct Ltd | Professional & scientific | 2018 |
| Natcha Ltd | Health & social care | 2015 |
| National ELF Service Limited | Information & communication | 2015 |
| Nationwide Barbers Limited | Extraterritorial | 2015 |
| Nationwide Fashion.Co Limited | Wholesale & retail | 2026 |
| Natlus Limited | Professional & scientific | 2008 |
| Natset Trading Ltd | Hospitality | 2018 |
| Naturaglow OIL Ltd | Wholesale & retail | 2025 |
| Natural & Complementary Health Limited | Manufacturing | 2023 |
| Natural History Ltd | Administrative & support | 2009 |
| Natural Hydrogen Consultants Limited | Professional & scientific | 2023 |
| Natural Stone and Tile Imports Ltd | Construction | 2026 |