| Miracle Health Ltd | Other services | 2026 |
| Misterroy Limited | Transport & logistics | 1996 |
| Mitchell Beckett Homes Limited | Real estate | 2020 |
| Mjls Trading Limited | Wholesale & retail | 2025 |
| MJM Properties Ltd | Real estate | 2026 |
| MK Inter Ltd | Manufacturing | 2018 |
| Mkspropertymaintenance Ltd | Construction | 2020 |
| ML Properties Essex Ltd | Real estate | 2025 |
| MM Drylining Services Ltd | Construction | 2020 |
| Modern Heritage Limited | Construction | 2019 |
| Mojo Design Limited | Professional & scientific | 1996 |
| MOM Ltd | Professional & scientific | 2014 |
| Momutad Ltd | Health & social care | 2014 |
| Monday Limited | Extraterritorial | 2009 |
| Monico Amusements Limited | Arts & recreation | 2005 |
| Monico Leisure Limited | Hospitality | 1996 |
| Monn Housing Ltd | Real estate | 2025 |
| Moons Investment Co. Limited | Real estate | 1996 |
| Moons Property Developments Limited | Extraterritorial | 2007 |
| Moor Sportz Limited | Education | 2025 |
| Moorlands Energy Ltd | Energy | 2021 |
| Moose London Limited | Other services | 2015 |
| Morelli's Cappuccino Bars (Basildon) Limited | Hospitality | 2005 |
| Mori Consult Ltd | Information & communication | 2022 |
| Mortgageemz Limited | Financial services | 2025 |
| Mortimer Stamps Limited | Wholesale & retail | 2026 |
| Moviestarr Limited | Extraterritorial | 2016 |
| Mozart Compliance Solutions Limited | Administrative & support | 2025 |
| MPH Investments Ltd | Real estate | 2018 |
| MPL Site Services (Bracknell) Limited | Administrative & support | 2019 |
| MPL Site Services (Heathrow) Ltd | Administrative & support | 2014 |
| MPL Site Services Limited | Administrative & support | 2004 |
| Mproofing Ltd | Construction | 2013 |
| MPS Painting and Decorating Limited | Construction | 2011 |
| MRA Construct Ltd | Construction | 2021 |
| MRS Salisburys of Coggeshall Ltd | Hospitality | 2024 |
| MSB & Co Canvey Island Limited | Professional & scientific | 2020 |
| MU Groundworks Limited | Construction | 2012 |
| Munchies Kebab Desert Ltd | Hospitality | 2025 |
| Murree Staffing Services Limited | Administrative & support | 2021 |
| Murree Support Services Limited | Administrative & support | 2019 |
| Musoke Limited | Health & social care | 2015 |
| MV and EW Limited | Real estate | 2024 |
| MV and EW SUB Ltd | Real estate | 2025 |
| MW Industries Ltd | Health & social care | 2018 |
| My Dream Car Ltd | Wholesale & retail | 2020 |
| Myelec Limited | Extraterritorial | 2012 |
| N&N GAS Fitters Limited | Construction | 2017 |
| N14YCE Ltd | Professional & scientific | 2015 |
| N2 Electrical Ltd | Construction | 2020 |
| Nabgem Holdings Ltd | Real estate | 2024 |
| Nabgem Ltd | Real estate | 2024 |
| Naftaliventures Limited | Real estate | 2025 |
| Najaka Properties Limited | Financial services | 2016 |
| Nakonaum Limited | Arts & recreation | 2026 |
| Nakonaum Management Limited | Financial services | 2026 |
| Nakonaum Properties Limited | Real estate | 2026 |
| Nasco Services Ltd | Hospitality | 2016 |
| Nascroft Properties Ltd | Real estate | 2014 |
| Nassa Properties Limited | Households | 2019 |
| Natem Group Ltd | Professional & scientific | 2021 |
| National Events Caterers Limited | Hospitality | 2019 |
| Nationwide Traffic Limited | Construction | 2024 |
| Natural Space Design Limited | Professional & scientific | 2021 |
| Natural Space Property & Finance Ltd | Financial services | 2023 |
| Natures First Limited | Extraterritorial | 2015 |
| Nawab Dynasty Ltd | Hospitality | 2024 |
| Nawab Entertainment Ltd | Hospitality | 2024 |
| NBD Property Limited | Real estate | 2021 |
| NBTWENTY2 Ltd | Wholesale & retail | 2025 |
| NCM Pre-Fab Limited | Administrative & support | 2025 |
| NDS Mechanical Services Limited | Administrative & support | 2003 |
| NEE NAW Parties Ltd | Health & social care | 2020 |
| Nelmo & Co Limited | Professional & scientific | 2011 |
| Nevill Developments Limited | Construction | 2001 |
| New Byte Order Limited | Information & communication | 2020 |
| Newbridge Accident Repair Centre (Basildon) Ltd | Extraterritorial | 2012 |
| Newbridge Accident Repair Centre (Dartford) Ltd | Wholesale & retail | 2023 |
| Newbridge Accident Repair Centre (London) Ltd | Wholesale & retail | 2011 |
| Newbridge Accident Repair Centre Ltd | Wholesale & retail | 2006 |
| Newbridge Group (Holdings) Limited | Financial services | 2023 |
| Newbridge Group Limited | Wholesale & retail | 2017 |
| Newbridge Sports Horses Limited | Agriculture & fishing | 2015 |
| Newfi Ltd | Professional & scientific | 2018 |
| Newtech Consulting Limited | Information & communication | 2017 |
| Nexis Security Group Limited | Construction | 2025 |
| Next-Age Consulting Ltd | Information & communication | 1999 |
| Nguyen HD Ltd | Other services | 2025 |
| Nicholas James Fire Protection & Security Engineers Ltd | Professional & scientific | 2001 |
| Nicholls Fire Services Ltd | Construction | 2025 |
| Nighttide Limited | Other services | 2024 |
| Ninsight Publications Limited | Information & communication | 2021 |
| Ninty Media Limited | Information & communication | 2021 |
| Nladitan Limited | Other services | 2019 |
| Nldainius Ltd | Construction | 2022 |
| NO Shocks Electrical Ltd | Construction | 2009 |
| NO Small Beer Limited | Hospitality | 2015 |
| Nobi Cuts Ltd | Other services | 2019 |
| Noise TEC Systems Limited | Manufacturing | 2014 |
| North and South Property Services Limited | Construction | 2017 |