| Mirliton Productions | Information & communication | 2019 |
| MIRO57 Limited | Transport & logistics | 2017 |
| Miroslav Delivery Limited | Transport & logistics | 2026 |
| Miroslaw Mocarski Transport Ltd. | Transport & logistics | 2016 |
| Mirror Glass Processors Limited | Construction | 1990 |
| Mirror Image (Yorkshire) Limited | Manufacturing | 2018 |
| Mirror Sound Limited | Information & communication | 2023 |
| Mirrorq Limited | Wholesale & retail | 2025 |
| Mirsevo Solutions Ltd | Administrative & support | 2023 |
| Mirza 12 Ltd | Hospitality | 2024 |
| MIS Global Ltd | Administrative & support | 2022 |
| Misbah Tahir Ltd | Health & social care | 2026 |
| Misc Movements Limited | Arts & recreation | 2024 |
| Mischemix Ltd | Administrative & support | 2021 |
| Mishelley's Ltd | Hospitality | 2023 |
| Mishiana Care Ltd | Health & social care | 2024 |
| Mishsar Limited | Construction | 2024 |
| Miss Crystal Ltd | Manufacturing | 2024 |
| Miss Greene Ltd | Manufacturing | 2025 |
| Miss HD Limited | Information & communication | 2026 |
| Miss Penny's Cleaning Ltd | Administrative & support | 2024 |
| Miss Universe Film Ltd | Information & communication | 2026 |
| Mission Economics Ltd | Professional & scientific | 2024 |
| Mission Translations Limited | Professional & scientific | 2018 |
| Mission:Active C.I.C. | Education | 2020 |
| Mister Axle Holdings Limited | Financial services | 2026 |
| Mister Axle Ltd | Professional & scientific | 2021 |
| Mister Peebles Limited | Administrative & support | 2017 |
| Mister Vape International Ltd | Manufacturing | 2019 |
| Mistral (Kenwood Road) Management Company Limited | Households | 2004 |
| Mistral Entertainment Limited | Information & communication | 2008 |
| Misty Blue Ltd | Wholesale & retail | 2025 |
| Mitchel & King Skates Limited | Professional & scientific | 1984 |
| Mitchell Accounting Ltd | Professional & scientific | 2012 |
| Mitchellandhukinhair Ltd | Other services | 2024 |
| Mitec-Ndt Ltd | Construction | 2023 |
| Mitex (UK) Limited | Other services | 2009 |
| Mitotype Precision Labs Limited | Professional & scientific | 2025 |
| Mitrut Transport Limited | Transport & logistics | 2018 |
| Mitsue Limited | Wholesale & retail | 2007 |
| Mitsy's Caribbean Kitchen Ltd | Hospitality | 2020 |
| Miwa Enterprises Ltd | Wholesale & retail | 2026 |
| Miyoo Limited | Wholesale & retail | 2025 |
| Mizu Hospitality Ltd | Hospitality | 2026 |
| Mizuki Motors Limited | Wholesale & retail | 2024 |
| MJ & a Peel Properties Limited | Households | 2021 |
| MJ ANY Event Limited | Transport & logistics | 2019 |
| MJ Gleeson PLC | Financial services | 2014 |
| MJ Hughes Developments Limited | Construction | 2026 |
| MJ Hughes Structural Steel Limited | Professional & scientific | 2010 |
| MJ Professional Services Limited | Administrative & support | 2020 |
| MJ Surfacing Ltd | Construction | 2012 |
| Mj's Local Ltd | Wholesale & retail | 2021 |
| Mj's Properties South Yorkshire Ltd | Hospitality | 2021 |
| MJA Holdings Ltd | Construction | 2016 |
| Mjama Transport Ltd | Transport & logistics | 2016 |
| MJB Consulting Services Ltd | Administrative & support | 2016 |
| MJB Delivery Services Ltd | Transport & logistics | 2025 |
| MJB Joinery & Building Services Limited | Construction | 2016 |
| MJB Transport Ltd | Transport & logistics | 2025 |
| MJC Media Productions Ltd | Information & communication | 2012 |
| Mjceuropeantransport Ltd | Transport & logistics | 2026 |
| MJD Building Solutions Ltd | Construction | 2017 |
| MJE CAD Services Ltd. | Real estate | 2016 |
| MJF Cleaning Services Limited | Administrative & support | 2006 |
| MJG Supplements Limited | Wholesale & retail | 2011 |
| MJH Decorators Ltd | Construction | 2017 |
| MJJ Ltd | Health & social care | 2024 |
| MJJ Staffing Ltd | Health & social care | 2023 |
| MJK Steel Consulting Ltd | Professional & scientific | 2024 |
| MJK Transport Ltd | Transport & logistics | 2013 |
| Mjlx Ltd | Other services | 2026 |
| MJM Building Solutions Limited | Construction | 2023 |
| MJM Data Recovery Limited | Information & communication | 1999 |
| MJM88 Ltd | Wholesale & retail | 2026 |
| MJN Software Ltd | Information & communication | 2005 |
| MJO FX Limited | Administrative & support | 2011 |
| MJO Holdings Limited | Wholesale & retail | 2019 |
| MJP Performance Ltd | Arts & recreation | 2024 |
| MJR Engineering Solutions Limited | Other services | 2018 |
| Mjrcc Limited | Information & communication | 2018 |
| Mjreeder Ltd | Professional & scientific | 2025 |
| MJS Project Solutions Ltd | Information & communication | 2018 |
| MJS Signs Limited | Manufacturing | 2023 |
| MJT Engineering Limited | Professional & scientific | 2012 |
| MJT Precision Limited | Professional & scientific | 2025 |
| MJT Tiling Limited | Construction | 2025 |
| MJV Property Solutions Limited | Construction | 2023 |
| MJW Bathrooms Ltd | Construction | 2021 |
| MJW Performance Ltd | Wholesale & retail | 2022 |
| MJW Specialists Limited | Professional & scientific | 2010 |
| Mjwp Projects Ltd | Other services | 2020 |
| MK Auto Sales Ltd | Wholesale & retail | 2019 |
| MK Billericay Ltd | Arts & recreation | 2012 |
| MK Bodywork and Paint Limited | Manufacturing | 2026 |
| MK Coaching Ltd | Health & social care | 2021 |
| MK Corner Shop Ltd | Wholesale & retail | 2022 |
| MK Corporation Ltd | Real estate | 2018 |
| MK Elite Housing Limited | Construction | 2021 |
| MK Fitness Consulting Ltd | Administrative & support | 2021 |