| Manor Farm Energy Limited | Energy | 2013 |
| Manor Farm Feeds Limited | Manufacturing | 1995 |
| Manor Farm Investments Ltd | Financial services | 2019 |
| Manson & Co (Yorkshire) Limited | Information & communication | 2025 |
| Marine Court (Bridlington) Limited | Households | 2005 |
| Marine Point Management Services Limited | Households | 1995 |
| Mark Fanshaw Decorating Limited | Construction | 2002 |
| Mark Hart Motor Engineers Limited | Wholesale & retail | 2003 |
| Mark Hesp Paving & Groundworks Ltd | Construction | 2019 |
| Markopuse Ltd | Wholesale & retail | 2025 |
| Marsh Investments Bridlington Limited | Real estate | 2022 |
| Marshall Properties (Bridlington) Ltd | Households | 2019 |
| Marshall Property Ltd | Real estate | 2022 |
| Marshall Quarry Products Limited | Mining & quarrying | 1996 |
| Marshall Steel Buildings Ltd | Construction | 2017 |
| Marshall's High Street Building Company Limited | Real estate | 2018 |
| Martin Shipley Site Services Limited | Administrative & support | 2015 |
| Martindale Care Limited | Health & social care | 2015 |
| Martinezzzsleep Limited | Manufacturing | 2023 |
| Marton Care Homes Ltd | Health & social care | 2020 |
| Marton Care Limited | Health & social care | 2020 |
| Marton Care NO 2 Ltd | Health & social care | 2026 |
| Marton Grange Country House Ltd | Hospitality | 2019 |
| Marton Hall Leisure Limited | Professional & scientific | 2005 |
| Marton Valley Leisure Limited | Hospitality | 2017 |
| MASAL23 Ltd | Hospitality | 2025 |
| Masala Bridlington Ltd | Hospitality | 2023 |
| Masala Indian Cuisine Ltd | Hospitality | 2015 |
| Matthew Watson Transport Limited | Transport & logistics | 2011 |
| Maytree Buildings Ltd | Construction | 2006 |
| MBG Maintenance Limited | Construction | 2018 |
| MCH 2021 Ltd | Health & social care | 2021 |
| MCM Farm Services Limited | Agriculture & fishing | 2004 |
| Mcmichaell Limited | Wholesale & retail | 2025 |
| Mcpheat Ltd | Professional & scientific | 2020 |
| MDG Groundworks Ltd | Construction | 2015 |
| MDK Care Limited | Public administration | 2025 |
| Meds UK Limited | Wholesale & retail | 2009 |
| Megson Construction Limited | Construction | 2001 |
| Megson Utilities Limited | Construction | 2010 |
| Mercox Rigging & Lifting Services Ltd | Construction | 2024 |
| Meta-Design Limited | Professional & scientific | 2010 |
| Metcalfe Fabrications Limited | Construction | 2019 |
| Mfcl Limited | Professional & scientific | 2011 |
| MGM Houses Ltd | Real estate | 2024 |
| Michael Daly Caravans Limited | Wholesale & retail | 2023 |
| Mick Foster Limited | Wholesale & retail | 2015 |
| Mighty Lancer Games Ltd | Wholesale & retail | 2019 |
| Millbridge Leisure Park Limited | Hospitality | 2023 |
| Millfield Farming Limited | Agriculture & fishing | 2012 |
| Millhouse Carpets & Flooring Limited | Wholesale & retail | 2015 |
| Milli Property Ltd | Real estate | 2026 |
| Millie & Blake Ltd | Wholesale & retail | 2017 |
| Milo Mortgages UK Ltd | Financial services | 2026 |
| Mine Site Search Limited | Administrative & support | 2015 |
| Mirabelle Rentals Ltd | Real estate | 2024 |
| Mirage II Limited | Agriculture & fishing | 2010 |
| Mj&D Limited | Wholesale & retail | 2024 |
| MLB Developments Limited | Real estate | 2025 |
| Mlkwood Limited | Wholesale & retail | 2018 |
| Mnommnom Chish and Fips Ltd | Hospitality | 2019 |
| Modulus Systems Limited | Manufacturing | 1992 |
| Moments That Matter (North Yorkshire) Ltd | Hospitality | 2025 |
| Montara Events Ltd | Administrative & support | 2026 |
| Mooks Consultancy Limited | Professional & scientific | 2023 |
| Moorhouse Petroleum Limited | Mining & quarrying | 1994 |
| Mortons International Company Services Limited | Administrative & support | 1992 |
| Motion Sports Ltd. | Arts & recreation | 2025 |
| Motorbike Storage Space Ltd | Transport & logistics | 2025 |
| MP Residential Limited | Real estate | 2018 |
| MR Gift Limited | Wholesale & retail | 2020 |
| MS & YS Barker and SON Limited | Real estate | 2006 |
| MS Hunter Farming Ltd | Agriculture & fishing | 2021 |
| MSG Services (EY) Ltd | Wholesale & retail | 2010 |
| Multispace Systems Ltd | Construction | 2007 |
| Mundy Shot Blasting Limited | Administrative & support | 2022 |
| Muntons Malt Supply Chain Limited | Real estate | 2007 |
| Murray Hills Solicitors Limited | Professional & scientific | 2013 |
| Music Leisure Limited | Hospitality | 2007 |
| Mustard Groundworks Ltd | Construction | 2026 |
| MW Roofing (Bridlington) Ltd | Construction | 2011 |
| MWC Group Ltd | Professional & scientific | 2016 |
| MWM Developments Limited | Construction | 2023 |
| Mygul Group Limited | Wholesale & retail | 2023 |
| N R Jackson Limited | Agriculture & fishing | 2013 |
| N&L Coastal Properties Ltd | Other services | 2025 |
| N. Charles & SON Limited | Arts & recreation | 2004 |
| Nagra Properties Limited | Real estate | 2002 |
| National Caravan Supplies Ltd | Wholesale & retail | 2023 |
| Nautilus Imports Ltd | Wholesale & retail | 2003 |
| Navi Recruitment Solutions Ltd | Administrative & support | 2025 |
| Nbwtrading Ltd | Wholesale & retail | 2025 |
| NC Lettings Limited | Real estate | 2022 |
| Neil Whatling Decorite Limited | Construction | 2005 |
| Neville and Mary Mooney Hairdressers Limited | Other services | 2003 |
| New Wave Group (Yorkshire) Ltd | Other services | 2022 |
| Nexalmarket Ltd | Wholesale & retail | 2024 |
| Niche Housekeeping Services Ltd | Other services | 2017 |
| Niche Professional Services Limited | Professional & scientific | 2024 |
| Nicholls Car Sales Limited | Wholesale & retail | 2019 |