| Milton Pump Engineers Limited | Manufacturing | 1999 |
| Mimi's Ice Cream Factory Ltd | Wholesale & retail | 2025 |
| Mimi's Oasis Limited | Wholesale & retail | 2023 |
| Mimosa Unisex Haircuts Ltd | Other services | 2022 |
| Minalecom Ltd | Wholesale & retail | 2025 |
| Mind and Mind Ltd | Other services | 2023 |
| Mind Harmony Solutions Limited | Health & social care | 2024 |
| Mind Matters NE CIC | Health & social care | 2024 |
| Mind Mortal Ltd | Information & communication | 2025 |
| Mindful Cleaning Limited | Extraterritorial | 2018 |
| Mindful Gifting Limited | Other services | 2018 |
| Mindful Health Movement Limited | Health & social care | 2016 |
| Mindmerge Technologies Ltd | Information & communication | 2025 |
| Mindrisk Training Ltd | Education | 2026 |
| Mindserv Global Innovation Limited | Manufacturing | 2022 |
| Mindspark Consultants Limited | Professional & scientific | 2025 |
| Minel Leisure Limited | Hospitality | 2004 |
| Minel Venues LLP | | 2013 |
| Ming Kitchen Limited | Professional & scientific | 2013 |
| Minhoco 21 Limited | Manufacturing | 2013 |
| Minhoco 40 Limited | Hospitality | 2017 |
| Minhoco 41 Limited | Hospitality | 2017 |
| Minhoco 48 Limited | Hospitality | 2019 |
| Minhoco 57 Limited | Real estate | 2020 |
| Minhoco 61 Limited | Hospitality | 2021 |
| Minhoco 62 Limited | Financial services | 2021 |
| Minhoco 64 Ltd | Hospitality | 2021 |
| Minhoco 65 Limited | Financial services | 2021 |
| Minhoco 66 Limited | Hospitality | 2021 |
| Minhoco 80 Ltd | Financial services | 2023 |
| Minhoco 99 Limited | Financial services | 2026 |
| Mini BEE Photography Ltd | Professional & scientific | 2019 |
| Mini Campers Hire Limited | Administrative & support | 2019 |
| Mini Campers North East Limited | Wholesale & retail | 2012 |
| Mini Workgroups Ltd | Information & communication | 2024 |
| Minnehaha Events Limited | Administrative & support | 2015 |
| Minnie’S Pamper Parties Ltd | Other services | 2022 |
| Mint Business Club Ltd | Professional & scientific | 2017 |
| Mint Maintenance Limited | Administrative & support | 2012 |
| Mint Salon Ltd | Other services | 2021 |
| Mintbridge Development Ltd | Information & communication | 2015 |
| Minteck Limited | Health & social care | 2010 |
| Minted Envy Ltd | Administrative & support | 2025 |
| Minto Farms Limited | Real estate | 2023 |
| Minto Pet Supplies Ltd. | Manufacturing | 2024 |
| Minzu Investment Limited | Real estate | 2020 |
| Minzu Limited | Hospitality | 2018 |
| MIR Diamonds Ltd | Wholesale & retail | 2024 |
| MIR North East Properties Limited | Households | 2018 |
| MIR Properties North East Ltd | Real estate | 2023 |
| Mir's Builders Limited | Construction | 2024 |
| Mira Media Group Limited | Professional & scientific | 2018 |
| Mirac Kent Ltd | Hospitality | 2019 |
| Miraco Bridge Ltd | Real estate | 2024 |
| Mirage Cafe Limited | Hospitality | 2023 |
| Mirage Lounge Limited | Hospitality | 2023 |
| Mirame Tech Limited | Information & communication | 2025 |
| Mirana Ltd | Wholesale & retail | 2026 |
| Miras Property Limited | Real estate | 2023 |
| Miricioiu Limited | Professional & scientific | 2020 |
| Mirrors and Lights Limited | Wholesale & retail | 2010 |
| Mirza AB Ltd | Hospitality | 2022 |
| Mishragroup Ltd | Hospitality | 2025 |
| Misneach Holdings Ltd | Information & communication | 2022 |
| Miss Belle Ltd | Other services | 2019 |
| Miss Paint Ltd | Construction | 2025 |
| Mission Ctrl Services Limited | Information & communication | 2022 |
| Mistletoe Bakery Ltd | Manufacturing | 2021 |
| Mistral House Ltd | Real estate | 2019 |
| Mitali Media Ltd | Professional & scientific | 2020 |
| Mitchell & Davis Windows & Doors Limited | Construction | 2020 |
| Mitchell Lawson Logistics Ltd | Transport & logistics | 2025 |
| Mitchinson Casey Ltd | Real estate | 2017 |
| Mitford B Limited | Real estate | 2007 |
| Mitford Estate LLP | | 2008 |
| Mitford F Limited | Real estate | 2007 |
| Mithelp Limited | Households | 1988 |
| Mitoni Ltd | Financial services | 2024 |
| Mitron Ltd | Wholesale & retail | 2023 |
| Mitsumi UK Limited | Manufacturing | 1987 |
| Mizrach Healthcare Ltd | Other services | 2022 |
| MJ Armstrong Ltd | Health & social care | 2021 |
| MJ Food Enterprises | Hospitality | 2026 |
| MJ Repairs Ltd | Wholesale & retail | 2023 |
| MJA Prime Realty Ltd | Real estate | 2025 |
| Mjag Properties Ltd | Real estate | 2020 |
| MJB Garage Services Limited | Wholesale & retail | 2020 |
| MJB Improvements Ltd | Construction | 2025 |
| MJB Property NE Limited | Real estate | 2021 |
| MJC Accounting Services Limited | Professional & scientific | 2024 |
| MJD Bridal Limited | Wholesale & retail | 2009 |
| MJD Supply Corp Limited | Wholesale & retail | 2026 |
| Mjed Holdings Limited | Hospitality | 2025 |
| Mjej Consulting Limited | Real estate | 2025 |
| MJH Lifting Services Ltd | Manufacturing | 2018 |
| MJH Property Solutions Ltd | Real estate | 2026 |
| MJL Engineering Services Ltd | Professional & scientific | 2018 |
| MJL Roofing Limited | Construction | 2023 |
| Mjlc Offshore Ltd | Professional & scientific | 2025 |
| MJM Consultancy Ltd | Professional & scientific | 2020 |