| Modern Thrills Ltd | Wholesale & retail | 2024 |
| Molecular Medicine Limited | Education | 2021 |
| Moller Upstream Consultancy Ltd | Professional & scientific | 2023 |
| Monemus Limited | Professional & scientific | 2011 |
| Moneyspider Productions Limited | Information & communication | 1997 |
| Monica Curtis Associates Limited | Professional & scientific | 2017 |
| Monkey Networking Ltd | Information & communication | 2018 |
| Monkton Barn Galleries Limited | Real estate | 2011 |
| Monkton's Rustic Table Ltd | Hospitality | 2020 |
| Monners Developments Ltd | Real estate | 2026 |
| MONSIEUR9 Ltd | Professional & scientific | 2022 |
| Montagu Decorating Services Ltd | Professional & scientific | 2019 |
| Montagu Property Group Ltd | Real estate | 2019 |
| Montagu Property Holdings Ltd | Real estate | 2017 |
| Montagu Rose Ltd | Real estate | 2022 |
| Montague Park (Shinfield) NO. 5 Management Limited | Households | 2004 |
| Montescola Limited | Education | 2004 |
| Montrose Abercorn Ltd | Financial services | 2016 |
| Moon Rabbit Creations Ltd | Information & communication | 2015 |
| Moonstep IT Limited | Information & communication | 2011 |
| Moorcrofts Corporate Law Limited | Professional & scientific | 2002 |
| Moorcrofts LLP | | 2005 |
| Moorcrofts Trustees Limited | Professional & scientific | 2020 |
| Moore Services Ltd | Professional & scientific | 2019 |
| Morgan Immunology Research Limited | Health & social care | 2013 |
| Mostable Limited | Information & communication | 2025 |
| Moulden Marketing Limited | Administrative & support | 2000 |
| Mountain Images Limited | Manufacturing | 2018 |
| Mountaxxe Ltd | Real estate | 2018 |
| Mow-Town Garden Services Limited | Administrative & support | 2023 |
| MPH Consulting Ltd | Professional & scientific | 2021 |
| MSC Commercial Limited | Hospitality | 2010 |
| Msibc Consultancy Ltd | Professional & scientific | 2026 |
| MSM Cases Limited | Manufacturing | 2008 |
| Mulady Solutions Limited | Administrative & support | 2006 |
| Mundaydean Consulting Ltd. | Professional & scientific | 1998 |
| Mundaydean Land Ltd | Real estate | 2025 |
| Musketeers Properties Limited | Real estate | 2004 |
| MWD Plumbing and Heating Limited | Construction | 2021 |
| My Beauty Doctor Ltd | Health & social care | 2010 |
| My Event Worldwide Limited | Administrative & support | 2015 |
| My Wooden House Ltd | Manufacturing | 2017 |
| Myers & Myers Consulting Limited | Professional & scientific | 2020 |
| Mynutridna Limited | Health & social care | 2023 |
| Mystic Sisters Limited | Health & social care | 2022 |
| Nadified Services Limited | Health & social care | 2023 |
| Nahda International (UK) Limited | Extraterritorial | 2018 |
| Napier Clarke Architects Limited | Professional & scientific | 2014 |
| Nasla Limited | Health & social care | 2008 |
| Navitas Holdings Limited | Wholesale & retail | 2015 |
| NBL Asset Management Ltd | Financial services | 2020 |
| NC Tuition Marlow Ltd | Education | 2024 |
| Nebu Servers Ltd | Manufacturing | 2025 |
| Nelson Court Limited | Households | 1996 |
| Neptoverse Ltd | Information & communication | 2026 |
| NET Zero Projects Limited | Construction | 2021 |
| Neuronatural CIC | Education | 2025 |
| New Journey Marketing Limited | Professional & scientific | 2011 |
| New World Norm Ltd | Administrative & support | 2023 |
| Newdays Consulting Limited | Professional & scientific | 2022 |
| Newdays Pharmacy Limited | Health & social care | 2006 |
| Newlands Apac Holdings Limited | Financial services | 2026 |
| Newlands Capital Management Limited | Real estate | 2017 |
| Newlands Chase Management Company Limited | Households | 2008 |
| Newton Creative Limited | Information & communication | 2022 |
| Newtonian Systems Limited | Construction | 2019 |
| Nexa Living Limited | Hospitality | 2025 |
| Nexa Propco Limited | Real estate | 2023 |
| Nexbrook Limited | Professional & scientific | 2012 |
| Nexcache Limited | Information & communication | 2025 |
| Nexe Holdings Limited | Financial services | 2024 |
| Nexova Limited | Professional & scientific | 2023 |
| Next Owner Ltd | Wholesale & retail | 2026 |
| Next Technology Vision Limited | Manufacturing | 2007 |
| Nexum Projects Limited | Construction | 2023 |
| Nexus London Ltd | Construction | 2024 |
| Nexus Training & Consultation Ltd | Professional & scientific | 2024 |
| NGH Marlow Limited | Professional & scientific | 2011 |
| Nick Flint Limited | Administrative & support | 2005 |
| Nigel Brown Consulting Limited | Information & communication | 2021 |
| NMT IT Transformation Ltd | Information & communication | 2023 |
| NMX IT Solutions Ltd | Information & communication | 2015 |
| Noble 1NE Properties Ltd | Real estate | 2022 |
| Noisy Communications Limited | Professional & scientific | 2012 |
| Nominee 71 Limited | Financial services | 2015 |
| North West Hockey Limited | Arts & recreation | 2021 |
| Northfield Court (Henley) Residents Association Limited | Households | 1978 |
| Northways Consulting Limited | Information & communication | 2007 |
| Norwood Alternative Health Ltd | Health & social care | 2022 |
| Novel Design Ltd | Information & communication | 2011 |
| NOW Agile Ltd | Professional & scientific | 2023 |
| NRF Investments Limited | Real estate | 2019 |
| Numa Laser Clinic Wokingham Limited | Other services | 2026 |
| Number 18 Marlow Limited | Households | 2017 |
| Number Seven River Terrace Management Company Limited | Households | 2008 |
| Numinous Technologies Ltd | Professional & scientific | 2021 |
| Nutritank Community Interest Company | Education | 2018 |
| Nutshell Productions Limited | Information & communication | 2005 |
| Nuttings Wood Ltd | Agriculture & fishing | 2023 |
| Nuvitalab Ltd | Manufacturing | 2025 |