| MK Locksmiths Ltd | Administrative & support | 2025 |
| MK Property Rentals Ltd | Real estate | 2025 |
| Mmkazmierski Ltd | Administrative & support | 2019 |
| Mmlab Ltd | Wholesale & retail | 2024 |
| MMM Holdings Scarborough Ltd | Financial services | 2022 |
| MNL (UK) Limited | Manufacturing | 2002 |
| MOB Bling Ltd | Manufacturing | 2023 |
| Modular Design Solutions Ltd | Professional & scientific | 2025 |
| Modular Direct Limited | Professional & scientific | 2003 |
| Modular Technical Services Limited | Energy | 2021 |
| Moe's at Heta Ltd | Hospitality | 2025 |
| Molescroft Farm Children's Nursery Limited | Education | 2016 |
| Molescroft Farm Estate Limited | Financial services | 2022 |
| Molescroft Farms Limited | Agriculture & fishing | 1965 |
| Molescroft Mobility Ltd | Wholesale & retail | 2025 |
| Molesfarm Community Projects | Agriculture & fishing | 2011 |
| Monad Ticketing Limited | Information & communication | 2003 |
| Monkhouse Holdings Limited | Professional & scientific | 1997 |
| Monks Walk Inn Ltd | Hospitality | 2015 |
| Montgomery Holdings (Yorkshire) Limited | Construction | 2017 |
| Moor Hill Properties Limited | Real estate | 2022 |
| Morco GAS Services Limited | Wholesale & retail | 1977 |
| Morco Products Holdings Limited | Financial services | 2023 |
| Morco Products Limited | Wholesale & retail | 1899 |
| More Studio Ltd | Professional & scientific | 2017 |
| Morningstar 666 Limited | Financial services | 2024 |
| Motion Print Co Ltd | Manufacturing | 2025 |
| Moto SP Limited | Wholesale & retail | 2001 |
| Motogo Limited | Wholesale & retail | 2010 |
| Motorkarl Ltd | Wholesale & retail | 2015 |
| Mounce Hydrosmart Ltd | Information & communication | 2014 |
| Mount Kembla Communications Ltd | Professional & scientific | 2012 |
| Mount Pleasant Contracting Limited | Agriculture & fishing | 2010 |
| Mowbray Sports and Corporate Clothing Ltd | Manufacturing | 2010 |
| Mowbray Sports Events Ltd | Extraterritorial | 2020 |
| MP Cooper Properties Ltd | Real estate | 2020 |
| MQ Training Services Ltd | Other services | 2020 |
| MR Mole Limited | Information & communication | 2008 |
| Mrewa Real Estate Ltd | Real estate | 2025 |
| MRG Lettings Ltd | Real estate | 2019 |
| MRS X Limited | Professional & scientific | 2025 |
| MRT (Holdings) Limited | Financial services | 2004 |
| MSM Wright Consultancy Ltd | Professional & scientific | 2024 |
| MSW Solutions Ltd | Construction | 2022 |
| MTA Limited | Extraterritorial | 2024 |
| MTA Property Company Limited | Real estate | 2024 |
| MTA Software Solutions Limited | Information & communication | 2018 |
| Muddy Bears Limited | Hospitality | 2026 |
| Mulberry Residential Limited | Real estate | 2016 |
| Murdoch Associates Limited | Administrative & support | 2014 |
| MVO Trading Limited | Professional & scientific | 2013 |
| MW Farm Supplies Limited | Wholesale & retail | 2021 |
| MXR (B) Ltd | Other services | 2016 |
| My Delivery Service Ltd | Transport & logistics | 2020 |
| My Eventorium Ltd | Hospitality | 2023 |
| My Pockets Limited | Information & communication | 2011 |
| My Pockets People CIC | Information & communication | 2015 |
| My Spot Ltd | Real estate | 2022 |
| Mydeepclean.Com Ltd | Professional & scientific | 2020 |
| Myers Engineering Ltd | Professional & scientific | 2026 |
| Myretrofit Limited | Administrative & support | 2021 |
| Mysa & Co Wellness Ltd | Wholesale & retail | 2025 |
| MZ Sports Media Limited | Professional & scientific | 2023 |
| N D H Associates Limited | Real estate | 1999 |
| N D Lunn Limited | Transport & logistics | 1998 |
| N P M Associates Ltd | Professional & scientific | 2012 |
| NAA Properties Limited | Real estate | 2013 |
| Nails Nails Nails EH Ltd | Other services | 2025 |
| Nala Distribution Ltd | Hospitality | 2024 |
| Napolini Ltd | Hospitality | 2019 |
| National Access Engineering Limited | Professional & scientific | 2026 |
| National Futsal League C.I.C. | Arts & recreation | 2020 |
| Nationwide Concrete Flooring Limited | Construction | 2007 |
| Naturewall Group Ltd | Manufacturing | 2018 |
| Naturewall Holdings Ltd | Financial services | 2022 |
| Naturewall Management Services Limited | Other services | 2024 |
| NBB Beverley Ltd | Wholesale & retail | 2014 |
| NCP Services Ltd | Professional & scientific | 2015 |
| Ndrw-Lvr Limited | Real estate | 2021 |
| NDT Sewell Services Limited | Professional & scientific | 2025 |
| Nearfield Artists Ltd | Arts & recreation | 2023 |
| Nebular Ventures Limited | Professional & scientific | 2024 |
| Neesom Investments Limited | Professional & scientific | 1971 |
| Neil Eastwood Independent Logistics Limited | Transport & logistics | 2022 |
| Nellingua Ltd. | Education | 2017 |
| NET Zero Powergrid Ltd | Other services | 2021 |
| Netavo Global Data Services Ltd | Information & communication | 2019 |
| New Century Glasshouses Ltd | Construction | 2007 |
| New EL Gusto Ltd | Hospitality | 2025 |
| New Ocean Leisure (UK) Limited | Hospitality | 2019 |
| New Paths Music Limited | Arts & recreation | 2017 |
| New Riverwalk Ltd | Administrative & support | 2021 |
| New Road (Driffield) Flats Limited | Households | 2004 |
| New Tech Import Limited | Transport & logistics | 2000 |
| New UNI Market Limited | Wholesale & retail | 2018 |
| Newbegin Consulting Limited | Professional & scientific | 2013 |
| Newbegin House Limited | Hospitality | 2020 |
| Newdays (Solutions) Limited | Professional & scientific | 2010 |
| Newholm Retreat Limited | Hospitality | 2024 |
| Newland Management Services Ltd | Households | 2014 |