| Matcha Properties Ltd | Real estate | 2024 |
| Mather Field Medical Ltd | Professional & scientific | 2016 |
| Matica Consult Limited | Other services | 2014 |
| Matthew Ellis Contracts Limited | Professional & scientific | 2023 |
| Maven Technology Group Ltd | Manufacturing | 2019 |
| Maxwell Scott Travel Limited | Administrative & support | 2014 |
| Maybe Later Restaurant Ltd | Hospitality | 2024 |
| Mayfield Mortgages Limited | Administrative & support | 2008 |
| MB Developments York Ltd | Manufacturing | 2021 |
| MB Holdings (Yorkshire) Ltd | Financial services | 2025 |
| MC Foodservice Consultancy Ltd | Professional & scientific | 2019 |
| MCA Valets Ltd | Administrative & support | 2024 |
| Mccauley & Hanna Ltd | Information & communication | 2023 |
| Mcelwee Consulting Ltd | Professional & scientific | 2020 |
| Mckay Property Investments (Leeds) Limited | Real estate | 2023 |
| Mcmahon Psychiatry Ltd | Health & social care | 2026 |
| Mctale Ltd | Professional & scientific | 2015 |
| MD Construction Consulting Limited | Professional & scientific | 2021 |
| Meadow Technology Limited | Wholesale & retail | 2007 |
| Meadowvale Estates Limited | Construction | 1997 |
| Meat Outdoors Ltd | Hospitality | 2016 |
| Media Ambitions (Enterprises) Limited | Arts & recreation | 2005 |
| Mediahouse Marketing & Advertising Ltd | Professional & scientific | 2011 |
| Medical Engineers UK Ltd | Extraterritorial | 2011 |
| Medical Marketing Consultancy Ltd | Professional & scientific | 2018 |
| Medical Thinking Ltd | Professional & scientific | 2022 |
| Medicus Optimum Limited | Health & social care | 2016 |
| Medisell Consultancy Ltd | Professional & scientific | 2025 |
| Medisurgical Ltd | Professional & scientific | 2015 |
| MEE Partners Ltd | Financial services | 2016 |
| Melhome Developments Limited | Construction | 1972 |
| Merchants Gate Management Limited | Households | 2002 |
| Metallic Fabrications Ltd | Manufacturing | 1996 |
| METALS4U Limited | Wholesale & retail | 2002 |
| Metartal Ltd | Manufacturing | 2024 |
| Metcalfe Builders Ltd | Construction | 2011 |
| Metriqzz UK Ltd | Professional & scientific | 2024 |
| MFB Group Holdings Ltd | Other services | 2018 |
| MFP Investments Limited | Real estate | 2017 |
| MGE Sports Consulting Limited | Professional & scientific | 2023 |
| Michael Pearson Limited | Other services | 2004 |
| Mick Tomo Limited | Other services | 2009 |
| Micklethwaite Flats Limited | Real estate | 1975 |
| Micklethwaite Planning Consultancy Limited | Professional & scientific | 2020 |
| Micorp Ltd | Professional & scientific | 2020 |
| Middletons Assured Talent Ltd | Administrative & support | 2014 |
| Midway Performing Arts Limited | Education | 2025 |
| Miipet Ltd | Professional & scientific | 2024 |
| Mike Skipsey Ltd | Health & social care | 2023 |
| Military Sanctuary Foundation CIC | Education | 2026 |
| Milner Richards Building Contractors Limited | Construction | 2026 |
| Milner Richards Property Limited | Construction | 2011 |
| Mimamac Limited | Real estate | 2003 |
| Minralis Limited | Wholesale & retail | 2021 |
| Minskyai Technology Limited | Information & communication | 2024 |
| Missy Grey Events Ltd | Hospitality | 2018 |
| MJ Empire Limited | Real estate | 2018 |
| MJJ Holdings Limited | Financial services | 2020 |
| MJW (Leeds) Limited | Construction | 2024 |
| MK Design and Project Services Ltd. | Construction | 2014 |
| MKL Landscaping Ltd | Construction | 2026 |
| Mlrb Limited | Wholesale & retail | 2022 |
| MNS Computer Services Limited | Real estate | 1989 |
| MNS Properties Limited | Real estate | 2015 |
| Moda Emerald Management Co Limited | Real estate | 2021 |
| Moda Emerald Midco Limited | Financial services | 2021 |
| Moda Heating Limited | Wholesale & retail | 2021 |
| Moda Life (Project Acorn) Limited | Real estate | 2026 |
| Moda Life Limited | Real estate | 2016 |
| Moda Life Management Limited | Real estate | 2019 |
| Moda Living (Angel Gardens) Limited | Extraterritorial | 2014 |
| Moda Living (Broad Street) Limited | Real estate | 2015 |
| Moda Living (Great Charles Street) Limited | Construction | 2017 |
| Moda Living (Heworth Green) Limited | Real estate | 2019 |
| Moda Living (Holland Street) Limited | Real estate | 2015 |
| Moda Living (Lancefield Quay) Limited | Real estate | 2021 |
| Moda Living (London West) Limited | Real estate | 2021 |
| Moda Living (Milton Keynes) Limited | Extraterritorial | 2021 |
| Moda Living (New Garden Square) Limited | Real estate | 2021 |
| Moda Living (Pbsa) Limited | Construction | 2024 |
| Moda Living (Princes Dock) Limited | Real estate | 2015 |
| Moda Living (Project Acorn) Limited | Extraterritorial | 2017 |
| Moda Living (Project Hagrod) Limited | Real estate | 2022 |
| Moda Living (Project Maybury) Limited | Extraterritorial | 2021 |
| Moda Living (Project Osprey) Limited | Extraterritorial | 2022 |
| Moda Living (Project Sandygate) Limited | Real estate | 2022 |
| Moda Living (Sackville Road) Limited | Construction | 2018 |
| Moda Living (Soyo A&D) Limited | Construction | 2024 |
| Moda Living (Springside Block E) Limited | Real estate | 2019 |
| Moda Living (Springside) Limited | Extraterritorial | 2016 |
| Moda Living (SYD) Limited | Real estate | 2023 |
| Moda Living Limited | Real estate | 2014 |
| Moda Works Limited | Extraterritorial | 2016 |
| Modav UK Limited | Professional & scientific | 2006 |
| Mode Hair Studio Ltd | Other services | 2020 |
| Mode Living Yorkshire Ltd | Wholesale & retail | 2020 |
| Modesty Performance Ltd | Manufacturing | 2015 |
| Moji's Pizzeria (Wetherby) Limited | Hospitality | 2002 |
| Molecheck UK Limited | Health & social care | 2006 |
| Moment to Paws Ltd | Other services | 2020 |