| Love Farming Ltd | Agriculture & fishing | 2011 |
| Lovell & Arne Ltd | Professional & scientific | 2022 |
| Lowery Consulting Limited | Professional & scientific | 2013 |
| LSJ Electrical Limited | Professional & scientific | 2025 |
| LSW Property Ltd | Real estate | 2026 |
| Lucien Enterprises Ltd | Professional & scientific | 2024 |
| Lucy Camm Limited | Financial services | 2018 |
| Lucy Usher Aggregates Limited | Wholesale & retail | 2023 |
| Lumiere Nail & Beauty Ltd | Other services | 2026 |
| Luminous Vision Limited | Financial services | 2024 |
| Lumley Construction Ltd | Construction | 2016 |
| Lumory Ltd | Information & communication | 2025 |
| Luxor Transfers Ltd | Transport & logistics | 2025 |
| Lynx Educational Academy C.I.C. | Education | 2015 |
| Lynxtra Limited | Other services | 2017 |
| M & a Energy Services Limited | Professional & scientific | 2026 |
| M & B Fixing Ltd | Other services | 2017 |
| M & T Traders (Retford) Limited | Wholesale & retail | 2010 |
| M a Brown Steel Services Limited | Construction | 2010 |
| M H Design Solutions Limited | Professional & scientific | 2010 |
| M K Steel Works Ltd | Manufacturing | 2018 |
| M K Survey & Design Works Ltd | Professional & scientific | 2025 |
| M V Construction (D & B) Limited | Construction | 2018 |
| M W J Estates LLP | | 2014 |
| M Wright Pipework Limited | Construction | 2020 |
| M&F Contractors Ltd | Construction | 2026 |
| M&G Paulson Limited | Agriculture & fishing | 2012 |
| M.E. Twidale & Sons Limited | Agriculture & fishing | 2011 |
| M2 Global Investments Limited | Real estate | 2010 |
| M2D (Retford) Limited | Financial services | 2014 |
| M2DF Engineering Limited | Financial services | 2012 |
| Machine Control Forum Ltd | Information & communication | 2020 |
| Mackley Pumps Limited | Professional & scientific | 2001 |
| Maclaren Associates Ltd | Administrative & support | 2016 |
| MAD Solutions Ltd | Information & communication | 2024 |
| Madame Crepe Ltd | Hospitality | 2020 |
| Mahony and Company Ltd | Financial services | 2013 |
| Maids by England Ltd | Administrative & support | 2016 |
| Main Asset Limited | Professional & scientific | 2023 |
| Maira’S Eatery DN22 Limited | Hospitality | 2026 |
| Major Oak Joinery Limited | Construction | 2024 |
| Malom Accountancy and Payroll Ltd | Professional & scientific | 2009 |
| Mamma Giusi's (Retford) Ltd | Hospitality | 2023 |
| Mamma’S Hub Kitchen Ltd | Hospitality | 2024 |
| Manby Road Property Limited | Extraterritorial | 2014 |
| Maple Financial Limited | Financial services | 2017 |
| Maple HR Limited | Administrative & support | 2022 |
| Maps Road Markings Ltd | Construction | 2021 |
| Marcus Bell Ltd | Wholesale & retail | 2020 |
| Marelli UK Limited | Professional & scientific | 1984 |
| Marine Zero Holdings Limited | Professional & scientific | 2021 |
| Marine Zero Limited | Professional & scientific | 2021 |
| Mark Stephenson PTA Limited | Education | 2016 |
| Markham Hotel Limited | Real estate | 1999 |
| Markham Moor Truck Stop Cafe Ltd | Hospitality | 2024 |
| Marque Homes Ltd. | Construction | 1999 |
| Marrew Construction Limited | Construction | 2024 |
| Marriott FOX Property Limited | Construction | 2026 |
| Marriotts Driving School Limited | Education | 2024 |
| Marshall Management and Consultancy Limited | Hospitality | 2009 |
| Marton Land Holdings Ltd | Construction | 2026 |
| Matt Cook Limited | Construction | 2014 |
| Matter of Life Ltd | Arts & recreation | 2022 |
| Mattersey Rifle and Pistol Club Limited | Other services | 2012 |
| Mattis Limited | Professional & scientific | 2013 |
| Maximum Specialist Cars Ltd | Wholesale & retail | 2017 |
| MB3D Design Services Ltd | Other services | 2021 |
| MBH Fireplaces Limited | Construction | 2009 |
| Mbrs Aydinoglu Limited | Real estate | 2015 |
| MC2 Procurement Limited | Professional & scientific | 2013 |
| MCA Property Group Limited | Construction | 2018 |
| MCC Business Services Retford Ltd. | Wholesale & retail | 1993 |
| Mccallum Leisure Ltd | Hospitality | 2025 |
| MCG European Ltd | Wholesale & retail | 2016 |
| MDM Plumbing & Heating (Notts) Limited | Construction | 2024 |
| MDP Catering Limited | Hospitality | 2010 |
| Mechinetic Ltd | Manufacturing | 2013 |
| Medetcrown Limited | Real estate | 1981 |
| Megs Food Ltd | Hospitality | 2026 |
| Melissa Nicola Therapeutic Services Ltd | Health & social care | 2021 |
| Mellors Livestock Limited | Extraterritorial | 1983 |
| Memento Care Limited | Health & social care | 2013 |
| Mendes (Investigation Services) Limited | Administrative & support | 2010 |
| MEP Tech Services Ltd | Professional & scientific | 2026 |
| Merton Surfacing Ltd | Construction | 2010 |
| MH Engineering Solutions Ltd | Wholesale & retail | 2025 |
| Michael GEE Transport Limited | Transport & logistics | 2017 |
| Michael Nichol-Smith Limited | Professional & scientific | 2010 |
| Microgeneration Technologies Ltd | Construction | 2013 |
| Midland Lifts (Installations) Limited | Professional & scientific | 2003 |
| Midlands Driving Trials Limited | Arts & recreation | 2004 |
| Mike Wintle Educational Consultant Limited | Education | 2011 |
| Mikenboard Limited | Professional & scientific | 2000 |
| Milanda (Consultancy) Limited | Other services | 2003 |
| Miles (Leverton) Limited | Wholesale & retail | 2016 |
| Miles Safer Ltd | Professional & scientific | 2025 |
| Miles Safety Consulting Ltd | Professional & scientific | 2017 |
| Mill Associates Limited | Wholesale & retail | 2008 |
| Mill Farm Merchants Limited | Wholesale & retail | 1990 |
| Millgrove Aggregate Limited | Wholesale & retail | 1964 |