| Marta Klinta Ltd | Professional & scientific | 2025 |
| Martin Marine Limited | Arts & recreation | 2015 |
| Martin VON Bergen Team Ltd | Extraterritorial | 2022 |
| Martin Whiteley Limited | Agriculture & fishing | 2013 |
| Martins Garden Machinery Limited | Professional & scientific | 2002 |
| Marula Automation Ltd | Construction | 2018 |
| Marwell Beds Ltd | Manufacturing | 2021 |
| Maryam Pharma Limited | Health & social care | 2017 |
| Marygate House Development Limited | Real estate | 2019 |
| Maryuk Limited | Transport & logistics | 2021 |
| Mase Transport Limited | Transport & logistics | 2025 |
| Mash JV Ltd | Health & social care | 2023 |
| Mash Medical Limited | Health & social care | 2022 |
| Maskill Holdings Limited | Real estate | 2021 |
| Mason Commercial Ltd | Professional & scientific | 2023 |
| Masonic Hall Company (Wakefield) Limited(The) | Other services | 1947 |
| Masons Construction Ltd | Construction | 2022 |
| Mass Group Services UK Ltd | Construction | 2015 |
| Massimo Express Limited | Hospitality | 2026 |
| Massimo Pizza (Wakefield) Ltd | Hospitality | 2023 |
| Massimo Pizza and Kebab Ltd | Hospitality | 2025 |
| Master Plast Ltd | Professional & scientific | 2011 |
| Master Quality Healthcare Services Ltd | Health & social care | 2012 |
| Master Tier Gaming CIC | Education | 2023 |
| Masterwork Automation Ltd | Manufacturing | 2020 |
| Matcon Engineering Limited | Professional & scientific | 2025 |
| Material Evolution LAB Ltd | Professional & scientific | 2016 |
| Maths Revolution Academy Limited | Education | 2024 |
| Matrik Computer Services Limited | Administrative & support | 2003 |
| Matrix Logistics Ltd | Transport & logistics | 2024 |
| Mattech Engineering Limited | Professional & scientific | 2012 |
| Matthew Aylard AI Consultancy Ltd | Information & communication | 2026 |
| Matthew High Contractors Limited | Construction | 2003 |
| Mattress & Divan Centre Ltd | Wholesale & retail | 2022 |
| Mavas Pizza Fast Food Ltd | Hospitality | 2025 |
| Maven TV Ltd | Information & communication | 2018 |
| MAX & Co Dog Boutique Ltd | Wholesale & retail | 2020 |
| MAX Couriers (Yorkshire) Ltd | Transport & logistics | 2017 |
| MAX Detailing Ltd | Administrative & support | 2025 |
| MAX Drywall Limited | Construction | 2019 |
| MAX Oberwegner Ltd. | Professional & scientific | 2018 |
| MAX Thomas Developers Limited | Construction | 2017 |
| Maxelerator Ltd | Information & communication | 2007 |
| Maxia Developments Limited | Real estate | 2022 |
| Maxim Telecom Ltd | Manufacturing | 2016 |
| Maxliner UK Ltd. | Wholesale & retail | 2026 |
| Maya & Co Properties Limited | Real estate | 2024 |
| Maybush Holdings Limited | Financial services | 2021 |
| Maybush Medical Centre Limited | Health & social care | 2024 |
| Maybush Medicare Limited | Wholesale & retail | 2023 |
| Maybush Pharmaceuticals UK Ltd | Manufacturing | 2025 |
| Mayfair Morris Ltd | Real estate | 2010 |
| Mayhems Solutions Limited | Manufacturing | 2014 |
| Mayman Property Solutions Ltd | Real estate | 2025 |
| Mayroyd Moorings Ltd | Real estate | 2019 |
| Mayu Rituals Ltd | Other services | 2026 |
| Mazar Restaurants Leeds Limited | Hospitality | 2021 |
| Maze Recruitment Group Ltd | Administrative & support | 2020 |
| Mazinident Ltd | Health & social care | 2018 |
| MB Construction & Sons Ltd | Construction | 2021 |
| MB Electrical & Renewables Ltd | Construction | 2025 |
| MB FIX2LET Limited | Real estate | 2025 |
| MB Freight Ltd | Transport & logistics | 2022 |
| MB Joiners Ltd | Manufacturing | 2021 |
| MB Trading House Limited | Information & communication | 2003 |
| Mbemz Ltd | Transport & logistics | 2024 |
| MBK Interiors Limited | Construction | 2015 |
| MBM Property Management Limited | Construction | 2021 |
| Mbps (UK) Limited | Real estate | 2015 |
| MBR Risk Solutions Ltd | Financial services | 2026 |
| MCC Facilities Limited | Construction | 2025 |
| Mcdr Services Limited | Construction | 2024 |
| Mcgrath Environmental Ltd | Professional & scientific | 2019 |
| Mcgrath Group Limited | Professional & scientific | 2019 |
| Mcgrath Trenchless Limited | Construction | 2019 |
| Mcgrath Utility Solutions Ltd | Construction | 2019 |
| Mcgregor Bros. Limited | Wholesale & retail | 1998 |
| Mcgregors Autosalvage Ltd | Wholesale & retail | 2026 |
| MCH Accounting Ltd | Professional & scientific | 2019 |
| Mckelvie Properties Limited | Real estate | 2025 |
| Mckenzie Fisher Limited | Professional & scientific | 2017 |
| Mcknight Developments Ltd | Construction | 2021 |
| Mcknight Investment Holdings Ltd | Financial services | 2023 |
| Mcleansdecor Limited | Construction | 2021 |
| Mcmanus Plumbing and Heating Limited | Construction | 2010 |
| Mcmorran Construction Limited | Construction | 2017 |
| Mcpherson Lawson Limited | Professional & scientific | 2013 |
| MCS (Yorkshire) Limited | Construction | 2018 |
| MD Foods (Yorkshire) Ltd | Wholesale & retail | 2022 |
| MD Joinery Manufacturers Ltd | Manufacturing | 2018 |
| MD Technologies Limited | Information & communication | 2026 |
| MD Trade Partners Ltd | Wholesale & retail | 2023 |
| MDG Foods Ltd | Wholesale & retail | 2016 |
| MDK Property Investments Ltd | Real estate | 2025 |
| MDM Wakefield Ltd | Hospitality | 2025 |
| MDS Car Sales Limited | Wholesale & retail | 2013 |
| MDS Homes PVS Ltd | Real estate | 2020 |
| Me-Too.Net Limited | Information & communication | 2000 |
| Meadow Automotive Limited | Wholesale & retail | 2016 |
| Meadow Development Group Ltd | Real estate | 2018 |