| Microbio-Eolas Limited | Professional & scientific | 2018 |
| Microbiology SL Ltd | Administrative & support | 2024 |
| Microsystem UK Limited | Administrative & support | 2003 |
| Microwave Inspection Technologies Ltd | Professional & scientific | 2014 |
| MID Cheshire Cabinetmaker Limited | Manufacturing | 2020 |
| Mid-Life Crisis Comedy Limited | Arts & recreation | 2023 |
| Midas Consultancy Services Ltd | Information & communication | 2009 |
| Midas Consultants Ltd | Professional & scientific | 2012 |
| Midas Ventures Ltd | Information & communication | 2013 |
| Midcol Properties Ltd | Real estate | 2025 |
| Middleton Commercial Properties Limited | Professional & scientific | 1991 |
| Middleton MAY Services Limited | Administrative & support | 2016 |
| Midgley Joinery & Interiors Limited | Construction | 2023 |
| Midlands and Coast Canal Carriers Ltd | Transport & logistics | 2018 |
| Midlife Beyond Limits Ltd | Health & social care | 2025 |
| Midon Limited | Transport & logistics | 2019 |
| Midsteel Northern Limited | Wholesale & retail | 1991 |
| Miers Legal Limited | Professional & scientific | 2017 |
| Mifflin Ltd | Professional & scientific | 2024 |
| MIG Experts Ltd | Transport & logistics | 2025 |
| Migo Enterprises Limited | Financial services | 2014 |
| Mihai Telecom Ltd | Information & communication | 2025 |
| Mike Constantia Artiste Management Ltd | Arts & recreation | 2005 |
| Mike Karim Consulting Limited | Administrative & support | 2024 |
| Mike Paton Engineering Design Limited | Administrative & support | 2012 |
| Mike Rhodes Accountancy Services Limited | Professional & scientific | 2022 |
| Mike Williams Benefits Limited | Administrative & support | 2009 |
| Mila Mini Market Ltd | Wholesale & retail | 2024 |
| Mila Process Solutions Ltd | Professional & scientific | 2025 |
| Mildred Digital Ltd. | Information & communication | 2018 |
| Mileage Asset Management Limited | Real estate | 2022 |
| Mileage IT Services Ltd | Information & communication | 2019 |
| Milebid Ltd | Professional & scientific | 2018 |
| Miles Omni Design Services Limited | Administrative & support | 2007 |
| Miles-Williams Consultancy Limited | Administrative & support | 2015 |
| Milesco Ltd | Information & communication | 2011 |
| Milestone IT Management Services Limited | Administrative & support | 2010 |
| Milhaltedlot Ltd | Real estate | 2025 |
| Militar Ltd | Manufacturing | 2020 |
| Milk-It Ltd | Extraterritorial | 2025 |
| Mill Brow Worsley Limited | Real estate | 2010 |
| Mill Croft (Management Company) Limited | Real estate | 2018 |
| Mill House Consultancy Ltd | Construction | 2024 |
| Mill Industrial Plastics Limited | Manufacturing | 2018 |
| Mill Test Services Limited | Administrative & support | 2014 |
| Millbrook Place (Crewe) Residents Management Company Limited | Households | 2024 |
| Millennials Fashion Ltd | Wholesale & retail | 2025 |
| Millennium Supplies Limited | Wholesale & retail | 2002 |
| Miller Hospitality Recruitment Limited | Professional & scientific | 2026 |
| Millers Specialist Joinery Ltd | Manufacturing | 1994 |
| Milliedolls Ltd | Agriculture & fishing | 2023 |
| Mills and Sons Properties Ltd | Real estate | 2025 |
| Millsdale Pharm Limited | Professional & scientific | 2012 |
| Millstone Durbax Limited | Manufacturing | 2021 |
| Milltech Consultancy Limited | Administrative & support | 2015 |
| Milman Project Management Limited | Administrative & support | 2012 |
| Milner Street Development Ltd | Real estate | 2016 |
| Milo Engineering Limited | Administrative & support | 2026 |
| Milsom Property Law Limited | Professional & scientific | 2025 |
| Mind - Unlimited Possibilities Ltd | Health & social care | 2025 |
| Mindcandy Consulting Limited | Administrative & support | 2010 |
| Mindful Housing Ltd | Extraterritorial | 2015 |
| Mindfully BE Ltd | Extraterritorial | 2019 |
| Mindgrove Ltd. | Information & communication | 2001 |
| Mindpurify Limited | Health & social care | 2023 |
| Minds EYE Presentations Limited | Professional & scientific | 2013 |
| Mingofish Properties Ltd | Extraterritorial | 2022 |
| Mini Shop Buttermarket Limited | Wholesale & retail | 2025 |
| Mini Soil Surveys North Ltd | Administrative & support | 2023 |
| Minidba Software Limited | Information & communication | 2019 |
| Ministry of Finest Ltd | Wholesale & retail | 2019 |
| Minity Ltd | Wholesale & retail | 2025 |
| Miniza Engineering Services Limited | Administrative & support | 2015 |
| MINNESOTA1 Ltd | Wholesale & retail | 2026 |
| Minnie Property 2 Limited | Real estate | 2025 |
| Minnie Property Limited | Real estate | 2025 |
| Minor Arcana Limited | Information & communication | 2019 |
| MINS01 Ltd | Transport & logistics | 2024 |
| Minwow Design Studios Limited | Professional & scientific | 2018 |
| Mipa Solutions Ltd | Construction | 2020 |
| MIR Advisory Ltd | Professional & scientific | 2025 |
| Mirac Catering Ltd | Hospitality | 2025 |
| Mirall Ltd | Hospitality | 2022 |
| Mircel Consulting Ltd | Information & communication | 2026 |
| Mires Group Holdings Limited | Professional & scientific | 2021 |
| Mirmac Limited | Manufacturing | 2002 |
| Miroc Limited | Professional & scientific | 2006 |
| Mirror Portfolio Monitoring Services Limited | Financial services | 2014 |
| Mirz Logistics Ltd | Transport & logistics | 2016 |
| Misa Holdings 123 Limited | Real estate | 2025 |
| Misk Consultancy Ltd | Information & communication | 2021 |
| Miska Tech Ltd | Information & communication | 2024 |
| Miss FOX Invents Limited | Arts & recreation | 2011 |
| Miss Frog Limited | Manufacturing | 2021 |
| Miss Mcfetridge Tutoring Limited | Administrative & support | 2025 |
| Mission THREE60 Ltd | Professional & scientific | 2017 |
| Missold Sipps Claims Limited | Professional & scientific | 2017 |
| Mistral Surveys Ltd | Professional & scientific | 2026 |
| Mitaylord Limited | Other services | 2017 |
| Mitchell Assets Limited | Professional & scientific | 2010 |