| Mindfulness Health Solutions Ltd | Health & social care | 2019 |
| Mindfulnest Solutions Ltd | Administrative & support | 2025 |
| MINE80 Limited | Public administration | 2025 |
| Minelco Minerals Ltd | Extraterritorial | 1909 |
| Minelco Specialities Ltd | Extraterritorial | 1973 |
| Mineral Trading Research Limited | Administrative & support | 2004 |
| Minerva Heights (Chichester) Management Company Limited | Households | 2020 |
| Ming's Court Ltd | Real estate | 2006 |
| Minha Property Limited | Real estate | 2026 |
| Minha Transport Ltd | Transport & logistics | 2024 |
| Mini Chic Ltd | Wholesale & retail | 2014 |
| Mini Dach Campers Ltd | Administrative & support | 2023 |
| Mini Fins Swim Academy Ltd | Education | 2022 |
| Ministry of Escapes Ltd | Arts & recreation | 2025 |
| Minoja Ltd | Real estate | 2026 |
| Minor Matters Limited | Professional & scientific | 1995 |
| Minster Conservatories, Doors & Windows Ltd | Construction | 2013 |
| Minster Products GD Limited | Professional & scientific | 2012 |
| Minster Surfacing Limited | Construction | 2000 |
| Mint (Eco) Ltd | Agriculture & fishing | 2021 |
| Mint Fresh Stays Ltd | Real estate | 2023 |
| Mint Place Cardiff Ltd | Real estate | 2025 |
| Minted Media Limited | Administrative & support | 2025 |
| MIR & Mortar Homes Ltd | Real estate | 2021 |
| Mirabooth Limited | Real estate | 2024 |
| Miracle Magic Ltd | Wholesale & retail | 2023 |
| Mircea Sotir Ltd | Wholesale & retail | 2020 |
| Mirch Masala (Derby) Ltd | Hospitality | 2021 |
| Mirembe Care Limited | Health & social care | 2019 |
| Mirena Healthcare Limited | Administrative & support | 2025 |
| Mirisha Property Limited | Real estate | 2022 |
| Mirpur Ways Limited | Transport & logistics | 2018 |
| Mirror Shine Auto Ltd | Construction | 2025 |
| Miscal Limited | Real estate | 2017 |
| Mischa Consulting Ltd | Professional & scientific | 2026 |
| Mischief Studio Limited | Information & communication | 2017 |
| Miss Coffee Ltd | Hospitality | 2015 |
| Miss Custom Denim Ltd | Arts & recreation | 2026 |
| Miss Great Britain Enterprises Limited | Arts & recreation | 2022 |
| Miss Great Britain Events Limited | Arts & recreation | 2024 |
| Mission Fitness/Martialarts Ltd | Arts & recreation | 2020 |
| Mission Millions Ltd | Real estate | 2020 |
| Mistech Global Ltd | Information & communication | 2025 |
| Mistry and Sons (Lettings) Limited | Real estate | 2023 |
| Mistry and Sons (Property) Limited | Real estate | 2018 |
| MIT Supplies Limited | Wholesale & retail | 2017 |
| Mitch's Wheel Repairs Ltd | Wholesale & retail | 2022 |
| Mitchell Management Associates Limited | Professional & scientific | 1988 |
| Mitchell-St.Joseph Ltd | Information & communication | 2014 |
| Mitee Consultancy Ltd | Information & communication | 2014 |
| Mitee Properties Ltd | Real estate | 2020 |
| Miths Ltd | Administrative & support | 2014 |
| Mitigator Ltd | Wholesale & retail | 2023 |
| Mitrab Limited | Other services | 2023 |
| MIX N MAC Ltd | Hospitality | 2018 |
| Mixing OUT Limited | Information & communication | 2013 |
| Miyagi Garcia Ltd | Hospitality | 2023 |
| Mizko Limited | Information & communication | 2026 |
| MJ Customs Ltd | Other services | 2022 |
| MJ Tonks Consulting Limited | Information & communication | 2025 |
| MJA Heating Services Limited | Construction | 2011 |
| MJB Building Services (Midlands) Limited | Construction | 2019 |
| MJC Plant Services Limited | Wholesale & retail | 2023 |
| MJD Geotechnical Ltd | Professional & scientific | 2016 |
| MJD Property Development Limited | Construction | 2019 |
| MJD Welding and Fabrication Limited | Manufacturing | 2026 |
| Mjgs Holdings Ltd | Manufacturing | 2020 |
| MJH Property & Development Ltd | Real estate | 2026 |
| MJJ Aviation Services Limited | Professional & scientific | 2020 |
| MJJ Business Consulting Limited | Professional & scientific | 2019 |
| Mjk-Ecommerce Limited | Wholesale & retail | 2025 |
| MJP Prop Limited | Real estate | 2022 |
| MJP Retail Ltd | Wholesale & retail | 2013 |
| MJS Customs and Retrofits Ltd | Wholesale & retail | 2026 |
| MJS Plumbing & Heating (Cheshunt) Limited | Construction | 2024 |
| MJS Stanley Ltd | Transport & logistics | 2019 |
| MJW Engineering Services Ltd | Professional & scientific | 2022 |
| MK Aesthetics Clinic Ltd | Other services | 2024 |
| MK Automotive Midlands Ltd | Wholesale & retail | 2025 |
| MK Family Lettings Ltd | Construction | 2022 |
| MK Hospitality Group Ltd | Hospitality | 2026 |
| MK Investments and Holdings Ltd | Real estate | 2022 |
| MK London Contractors Limited | Construction | 2021 |
| MK Luxury Hair & Beauty Ltd | Other services | 2023 |
| MK Modern Lettings Ltd | Real estate | 2022 |
| MK Ophthalmic Services Limited | Wholesale & retail | 2003 |
| MK Pharm Ltd | Wholesale & retail | 2022 |
| MK Property Development Derby Limited | Construction | 2024 |
| MK Property Ventures Ltd | Real estate | 2026 |
| MK Sameday Couriers Ltd | Manufacturing | 1978 |
| MK Shore Holdings Ltd | Financial services | 2021 |
| MK Studio Deluxe Ltd | Other services | 2024 |
| MK UK Holdings Limited | Wholesale & retail | 2022 |
| MKB Enterprise Ltd | Hospitality | 2026 |
| Mkind Ltd | Hospitality | 2026 |
| Mkkf Ltd | Information & communication | 2019 |
| MKM Logistics Ltd | Transport & logistics | 2022 |
| MKM Property Group Ltd | Real estate | 2026 |
| MKN Derby Ltd | Wholesale & retail | 2020 |
| Mkrfk Ltd | Construction | 2020 |