| Modal Energy Solutions Limited | Wholesale & retail | 2024 |
| Modarc Ltd | Professional & scientific | 2018 |
| Modu-Fit Limited | Manufacturing | 2012 |
| Modu-Lit Limited | Manufacturing | 2004 |
| Mogoza Ltd | Wholesale & retail | 2014 |
| Mollie and MIA Holdings Limited | Construction | 2020 |
| Mollie's Makers (Taunton) Ltd | Wholesale & retail | 2026 |
| Mommas Cafe Limited | Hospitality | 2012 |
| Monarchs Gymnastics C.I.C. | Education | 2024 |
| Monavista Properties Limited | Construction | 2026 |
| Mondexdesign Limited | Professional & scientific | 2017 |
| Monkleigh Barton Developments Ltd | Construction | 2024 |
| Monmouth Scientific Limited | Manufacturing | 2003 |
| Monument Investigations Limited | Administrative & support | 2008 |
| Moor SW Ltd | Administrative & support | 2022 |
| Moorhen Farm Estates Limited | Real estate | 2017 |
| Moorhouse Campsite Limited | Hospitality | 2026 |
| Moorland Pine Limited | Wholesale & retail | 2000 |
| Moorside Residents Limited | Households | 2000 |
| Moose 66 Ltd | Hospitality | 2022 |
| Morey Market Limited | Wholesale & retail | 2026 |
| Morrison Blood Limited | Professional & scientific | 2014 |
| Morti Sport & Play Limited | Construction | 2018 |
| Mosaik Holding Ltd | Financial services | 2017 |
| Mosaik Hospitality Ltd | Wholesale & retail | 2025 |
| Mosaik Loyalty Limited | Information & communication | 2026 |
| Mosaik Management Ltd | Financial services | 2026 |
| Motor Mice Limited | Manufacturing | 2006 |
| Motormouth Productions Limited | Arts & recreation | 2017 |
| Mouldex Ltd | Construction | 2018 |
| Moule & Jones Ltd | Administrative & support | 2026 |
| Moule Plumbing & Heating Ltd | Construction | 2026 |
| Mow&Trim Ltd | Administrative & support | 2018 |
| MPS Associates Limited | Financial services | 2025 |
| MPV IT Consultancy Ltd | Information & communication | 2018 |
| MRB Motors Ltd | Wholesale & retail | 2020 |
| Mrkr Fleet Solutions Ltd | Professional & scientific | 2025 |
| Mrkr Refrigeration Ltd | Professional & scientific | 2025 |
| Mrre Limited | Professional & scientific | 2012 |
| MRS Gorilla Vapes Ltd | Wholesale & retail | 2023 |
| MST Reinforcements Limited | Construction | 2024 |
| MTB Developments Ltd | Real estate | 2019 |
| MTM Passive Fire Protection Ltd | Construction | 2019 |
| MTS Southwest Ltd | Transport & logistics | 2024 |
| Mumbospecial Limited | Health & social care | 2014 |
| Munchies Kebab 1 Ltd | Hospitality | 2026 |
| Munex Group Ltd | Wholesale & retail | 2026 |
| Murati Homes Ltd | Real estate | 2025 |
| Mushah Ltd | Construction | 2025 |
| Muskan Gifts Ltd | Wholesale & retail | 2023 |
| Muslim Fit Ltd | Wholesale & retail | 2024 |
| My Blue Horizon Limited | Wholesale & retail | 2020 |
| Mybean Properties Ltd | Real estate | 2023 |
| N J Popham & SON Structures Ltd | Construction | 2015 |
| N R Higgs Limited | Construction | 2010 |
| N R Keedwell Limited | Transport & logistics | 2013 |
| N. a. Edwards ( General Builders ) Limited | Construction | 2004 |
| N.E. Motors Limited | Wholesale & retail | 2013 |
| N.I.O Lifestyle Ltd | Professional & scientific | 2020 |
| N.J. Popham & SON Ltd | Manufacturing | 2013 |
| NAB Plant Engineering Limited | Professional & scientific | 2010 |
| Nadel Finance Overseas Limited | Real estate | 1981 |
| Naga PAY UK Ltd | Information & communication | 2021 |
| Nailchemy Limited | Wholesale & retail | 2017 |
| Narla Transport Ltd | Transport & logistics | 2021 |
| Nash & Sons Electrical (Somerset) Limited | Construction | 2010 |
| NAT James Property Ltd | Construction | 2015 |
| Natasha Howarth Estate Agents Ltd | Real estate | 2020 |
| Natio Enterprises Limited | Extraterritorial | 2011 |
| National Holistic Society Limited | Health & social care | 2019 |
| Nationwide Amusements Ltd | Arts & recreation | 2019 |
| Natural Materials Ltd | Construction | 2020 |
| Natural Stone Consulting Limited | Administrative & support | 2009 |
| Natural Woven Products Limited | Extraterritorial | 2007 |
| Nature's Bond Sling Library CIC | Administrative & support | 2023 |
| Navitas Project Solutions Limited | Professional & scientific | 2005 |
| NAW Interim Ltd | Professional & scientific | 2025 |
| NBI Electrical (UK) Ltd | Construction | 2010 |
| NDR Studio Ltd | Professional & scientific | 2024 |
| Neighbouraid Ltd | Information & communication | 2026 |
| Nemean Construction Limited | Construction | 2021 |
| Neptunes Table LLP | | 2019 |
| Nest Homely Interiors Limited | Wholesale & retail | 2021 |
| NET Trade Solutions Ltd | Wholesale & retail | 2026 |
| Netgain Nutrition Limited | Education | 2024 |
| Nettlewood Limited | Real estate | 1987 |
| Network Attached Storage (UK) Limited | Information & communication | 2000 |
| Neuro Global Limited | Information & communication | 2026 |
| Neuromatters UK Ltd | Professional & scientific | 2025 |
| New Sass Ltd | Wholesale & retail | 2018 |
| Newdeal Limited | Manufacturing | 1996 |
| Newfield Logistics Ltd | Transport & logistics | 2014 |
| Newholme Hotel Ltd | Hospitality | 2024 |
| Newiams Building Services Ltd | Construction | 2025 |
| Newton Tavern Ltd | Hospitality | 2026 |
| Newtown & Victoria Springboard Ltd | Other services | 2005 |
| Nexus Global Health Limited | Professional & scientific | 2024 |
| Nexus IFA Limited | Financial services | 2011 |
| Nexus Support Services CIC | Professional & scientific | 2025 |
| NFJ Ventures Ltd | Manufacturing | 2026 |