| Measure Metrics Ltd | Information & communication | 2014 |
| Meatquill Trade Limited | Wholesale & retail | 2024 |
| MED Education Limited | Education | 2023 |
| MED21 Ltd | Other services | 2019 |
| Medball Limited | Health & social care | 2024 |
| Medihq Ltd | Education | 2024 |
| Meditate With Horses Ltd | Administrative & support | 2024 |
| Mediterranean Tours Limited | Administrative & support | 2009 |
| Melanit UK Ltd | Information & communication | 2025 |
| Melbec Development Limited | Professional & scientific | 2007 |
| Meldham Wood Luxury Lodges Limited | Hospitality | 2019 |
| Memberhub Ltd | Information & communication | 2023 |
| Memorisica Group Ltd | Information & communication | 2025 |
| Meowve - Lancashire Ltd | Professional & scientific | 2026 |
| Meranther Limited | Professional & scientific | 2018 |
| Merlin Control Systems Limited | Manufacturing | 1999 |
| Messrs G & M E Woodhouse & Sons Limited | Agriculture & fishing | 2023 |
| Metamark (UK) Limited | Manufacturing | 1992 |
| Metamark Technical Films Limited | Manufacturing | 2016 |
| Metis Cointelligence Ltd | Information & communication | 2026 |
| Metron Enterprises Ltd | Transport & logistics | 2024 |
| MF Window & Door Repairs Ltd | Construction | 2026 |
| Mgprojects Ltd | Administrative & support | 2025 |
| MH Secure Limited | Extraterritorial | 2024 |
| MH Stainton Homes Limited | Construction | 2015 |
| MHG Independent Social Work Ltd | Health & social care | 2023 |
| MHI Civils and Landscapes Limited | Administrative & support | 2022 |
| Mhlancaster Limited | Hospitality | 2022 |
| MHO Mayar Ltd | Real estate | 2016 |
| MI GEN CIC | Education | 2013 |
| Michael Andrews Compliance Solutions Ltd | Professional & scientific | 2024 |
| Michael Bond Design Associates Ltd | Wholesale & retail | 2015 |
| Michael Dutton Translation & Language Services Ltd | Manufacturing | 2022 |
| Micro Beauty Room Ltd | Other services | 2018 |
| Middle East Business Services Limited | Administrative & support | 2012 |
| Middle Highfield Property Management Limited | Households | 2006 |
| Mig-Tech Ltd | Information & communication | 2006 |
| Mihran & Samia Ltd | Wholesale & retail | 2015 |
| Mike Nixon Limited | Information & communication | 2024 |
| Mila Nails Ltd | Other services | 2024 |
| Mill House Flats (Lancaster) Limited | Households | 1982 |
| Millacre Court Limited | Households | 1995 |
| Milled & Found Ltd | Manufacturing | 2026 |
| Millers Ford Management Company Limited | Households | 2004 |
| Milliamp Laboratories Limited | Manufacturing | 2020 |
| Milliamp Technologies Limited | Manufacturing | 2009 |
| Mills Racing Limited | Arts & recreation | 2023 |
| Millstone Chippy Limited | Hospitality | 2019 |
| Mimmo Projects Limited | Real estate | 2023 |
| Mimshack Medical Services Limited | Health & social care | 2021 |
| Mindflow Training Ltd | Education | 2014 |
| Mindful PT Limited | Other services | 2021 |
| Minerva Heritage Limited | Professional & scientific | 2007 |
| Miniaturecity Ltd | Real estate | 2025 |
| Minni Stones Ltd | Wholesale & retail | 2025 |
| MIO Mondo Properties Ltd | Real estate | 2025 |
| Mirage Window Doors and Conservatories Limited | Construction | 2017 |
| Misso Hospitality Limited | Hospitality | 2023 |
| Mister Capital Holdings Limited | Real estate | 2006 |
| MJ Catterall Limited | Construction | 2014 |
| MJD Installations Ltd | Construction | 2014 |
| MJR Standen Ltd | Construction | 2025 |
| MJW Lighting Limited | Information & communication | 2019 |
| MK DOC Limited | Health & social care | 2022 |
| Mkbl Limited | Transport & logistics | 2024 |
| MKL Catering Ltd | Hospitality | 2020 |
| MM Groundworks and Construction Limited | Construction | 2026 |
| MMS Communications Limited | Professional & scientific | 2018 |
| Mobility & Healthcare Solutions Ltd | Manufacturing | 2018 |
| Mobilivity (UK) Limited | Information & communication | 2009 |
| Molito Limited | Professional & scientific | 2023 |
| Momalwasim Limited | Wholesale & retail | 2024 |
| Momeh Ltd | Health & social care | 2024 |
| Moments of Inspiration Ltd | Education | 2015 |
| Monday Night Media Limited | Professional & scientific | 2024 |
| Moneypenny Marketing Ltd | Professional & scientific | 2022 |
| Mongkok Lancaster Ltd | Hospitality | 2025 |
| Monkey Diggers Ltd | Wholesale & retail | 2016 |
| Monks Home Improvements Limited | Construction | 2025 |
| Montgomery Roofing Ltd | Construction | 2017 |
| Monthall Rise RTM Company Limited | Households | 2023 |
| Moonbeam Consulting Ltd | Professional & scientific | 2023 |
| Moonloft Limited | Other services | 2014 |
| Moorpark Consulting Limited | Professional & scientific | 2008 |
| Morecambe Bay Wills and Estates Limited | Professional & scientific | 2016 |
| Morecambe Carpets and Flooring Limited | Wholesale & retail | 2022 |
| Morecambe Community Care Limited | Extraterritorial | 2017 |
| Morecambe Community Riso Press CIC | Arts & recreation | 2022 |
| Morecambe Dinghy Angling Club Limited | Arts & recreation | 2002 |
| Morecambe Eats Limited | Hospitality | 2019 |
| Morecambe Fireplace Warehouse Limited | Wholesale & retail | 2002 |
| Morecambe Maritime Festival C.I.C. | Arts & recreation | 2024 |
| Morecambe Trucks Ltd | Extraterritorial | 2016 |
| Morecambe West END Properties Limited | Real estate | 2019 |
| Morecambe West Limited | Real estate | 2008 |
| Morehomes for the Bay (Developments) Limited | Construction | 2021 |
| Morehomes for the Bay (Investments) Limited | Construction | 2021 |
| Morgan Houses Limited | Real estate | 2020 |
| Morgan Roofing (Lancaster) Limited | Construction | 2003 |
| Morgan Three Wheeler Workshop Ltd | Wholesale & retail | 2021 |