| Midlands Metalheads Radio Limited | Information & communication | 2017 |
| Midlands Roofing & Building Ltd | Construction | 2025 |
| Midnight Mocha Ltd | Hospitality | 2025 |
| Mighty Creations Ltd | Wholesale & retail | 2021 |
| MII Facilities Ltd | Construction | 2026 |
| Miiec UK Limited | Education | 2020 |
| Mikcards Limited | Wholesale & retail | 2023 |
| Mike Ford Premier Coaching Ltd | Arts & recreation | 2002 |
| Mike Hackett 01 Services Ltd | Manufacturing | 2014 |
| Mike Hawes Consulting Ltd | Information & communication | 2012 |
| Mike Marsh Tooling Ltd | Manufacturing | 2020 |
| Mike Phoenix Scooters Limited | Wholesale & retail | 2004 |
| Mike Sports & Soccer Ltd | Manufacturing | 2022 |
| Mikys Properties Ltd | Real estate | 2023 |
| Milaad Islamic Educational Centre Ltd | Education | 2023 |
| Milaad Travels Ltd | Administrative & support | 2017 |
| Milanos Pizzeria Limited | Hospitality | 2004 |
| Milarest Ltd | Hospitality | 2024 |
| Mildtown Ltd | Professional & scientific | 2018 |
| Miles PER Hire Rentals Limited | Administrative & support | 2017 |
| Miles Street Salvage Ltd | Wholesale & retail | 2019 |
| Milestone Community Training Limited | Administrative & support | 2015 |
| Mileu Ltd | Wholesale & retail | 2020 |
| Miljo Properties Ltd | Construction | 2018 |
| Mill Lane Apartments Lune (Halton) Ltd | Households | 2022 |
| Mill Lane Apartments Lune Ltd | Other services | 2009 |
| Mill Park Gardens Management Company Limited | Households | 2019 |
| Mill Street Fencing and Decking Ltd | Professional & scientific | 2018 |
| Mill T Ltd | Wholesale & retail | 2023 |
| Mill Town Construction and Development Ltd | Construction | 2025 |
| Millar & Brown Holdings Ltd | Real estate | 2019 |
| Millard Electrical Ltd | Construction | 2022 |
| Millbank (Greenfield) Management Company Limited | Households | 2007 |
| Millbank Financial Solutions Limited | Financial services | 2013 |
| Millcroft Consultants Ltd | Professional & scientific | 2023 |
| Millennium Components Ltd | Manufacturing | 2019 |
| Millennium Tyres 786 Ltd | Wholesale & retail | 2019 |
| Miller Dickinson Limited | Construction | 2024 |
| Millerink Ltd | Other services | 2019 |
| Millers Floral Design Ltd | Wholesale & retail | 2015 |
| Millers Mews RTM Company Limited | Households | 2026 |
| Millers Nationwide Construction Limited | Construction | 2019 |
| Millfold Consulting Limited | Information & communication | 2023 |
| Millgate Arts Centre Limited | Arts & recreation | 2007 |
| Millgate Joiners and Builders Limited | Construction | 2009 |
| Millgate Property Developments Limited | Real estate | 2005 |
| Millhawk Ltd | Hospitality | 2020 |
| Millie Allen Limited | Professional & scientific | 2024 |
| Millie Grundy Limited | Other services | 2023 |
| Mills & Hegab Ltd | Wholesale & retail | 2018 |
| Mills Docs Limited | Information & communication | 2022 |
| Mills Hill Developments Limited | Hospitality | 2013 |
| Millsands Riverside Exchange RTM Company Limited | Households | 2026 |
| Millshill Kitchens & Bedrooms Ltd | Construction | 2018 |
| Millspring Limited | Professional & scientific | 2025 |
| Millstek Ltd | Wholesale & retail | 2017 |
| Millyshome Ltd | Wholesale & retail | 2021 |
| Milner Dental Care Ltd | Health & social care | 2021 |
| Milo Advisory Services Ltd | Professional & scientific | 2024 |
| Milo Royton Limited | Hospitality | 2019 |
| Min-Ho Ltd | Wholesale & retail | 2024 |
| Mind Sense Corporate (Business) Limited | Health & social care | 2024 |
| Mind Sense Therapy (Oldham) Limited | Health & social care | 2024 |
| Mind Sense Therapy (Rochdale) Ltd | Health & social care | 2024 |
| Mind Sense Therapy Limited | Health & social care | 2024 |
| Mindchain AI Limited | Wholesale & retail | 2025 |
| Mindful Dove CIC | Health & social care | 2024 |
| Mindful Mayhem Ltd | Health & social care | 2023 |
| Mindless Club Ltd | Wholesale & retail | 2025 |
| Mindset-Uk Ltd | Health & social care | 2025 |
| Mineonlinestore Holdings Limited | Real estate | 2020 |
| Minha Enterprises Ltd | Wholesale & retail | 2026 |
| Mini-Shoppers Ltd | Wholesale & retail | 2025 |
| Minibrand Ltd | Wholesale & retail | 2025 |
| Minimagicmart Ltd | Wholesale & retail | 2024 |
| Minimarket Convenience Limited | Transport & logistics | 2016 |
| Minimarket Grocery Ltd | Agriculture & fishing | 2025 |
| Minstercrest Limited | Real estate | 1986 |
| Mint Insights Ltd | Professional & scientific | 2024 |
| Mint Office Supplies Ltd | Wholesale & retail | 2015 |
| MIR Mode Limited | Wholesale & retail | 2023 |
| Mirage Adolescent Services Ltd | Health & social care | 2024 |
| Miray Optical Ltd | Health & social care | 2026 |
| Mirha Properties Ltd | Real estate | 2025 |
| Mirrortech Limited | Wholesale & retail | 2011 |
| Mirus Contracts Limited | Construction | 2024 |
| Mirus Quartz & Co Ltd | Manufacturing | 2026 |
| Mirus Retail Solutions Limited | Wholesale & retail | 2025 |
| Misan Estates Ltd | Real estate | 2026 |
| Mischief Consulting Ltd | Information & communication | 2017 |
| Mischief Properties Limited | Real estate | 2025 |
| Mishis Logistics Ltd | Transport & logistics | 2025 |
| Mismeasured Ltd | Wholesale & retail | 2017 |
| Miso Motors Ltd | Wholesale & retail | 2025 |
| Mistech Ltd | Wholesale & retail | 2024 |
| Mister Spain Limited | Transport & logistics | 2021 |
| Mitchellthree Ltd | Real estate | 2023 |
| Mitextiles Ltd | Wholesale & retail | 2026 |
| Miwas (NW) Limited | Professional & scientific | 2021 |
| Mixed Economy Ltd | Professional & scientific | 2026 |