| Mons Lucis Limited | Health & social care | 2024 |
| Monstera Ltd | Hospitality | 2019 |
| Montag Montane Ltd | Extraterritorial | 2023 |
| Montague Close Management Company Limited | Households | 2019 |
| Montana Prono Ltd | Information & communication | 2025 |
| Montgomery Services Limited | Construction | 2020 |
| Montriddy Holdings Limited | Information & communication | 2020 |
| Montriddy Limited | Real estate | 2015 |
| Montrose Heritage Limited | Real estate | 1995 |
| Montz Social Care Consultancy Limited | Public administration | 2020 |
| Mony’S Cafe Limited | Hospitality | 2025 |
| Monza Car Storage Ltd | Transport & logistics | 2025 |
| Mood Pants Ltd | Manufacturing | 2018 |
| Moods Investments Ltd | Real estate | 2022 |
| Mooma 1 Ltd | Wholesale & retail | 2013 |
| Moonlight Facilities Management Ltd | Administrative & support | 2021 |
| Moonlight Services PVT Ltd | Other services | 2026 |
| Moontree Tech Ltd | Information & communication | 2023 |
| Moore Creative Ltd | Professional & scientific | 2023 |
| Moore Steel Limited | Construction | 2007 |
| Moorland Gardens (Luton) Limited | Households | 2013 |
| Moorland Gardens Maintenance Company Limited | Households | 1981 |
| Moorthy Kannammal Sellappan Limited | Information & communication | 2023 |
| Moosekickz Ltd | Wholesale & retail | 2023 |
| Mopharm Limited | Health & social care | 2021 |
| Moracle Consulting Limited | Professional & scientific | 2020 |
| Moracle Foundation | Administrative & support | 2010 |
| Moracle Limited | Administrative & support | 2013 |
| Moralex Ltd. | Hospitality | 2020 |
| More Engineer Ltd | Professional & scientific | 2018 |
| More Health Partners Limited | Wholesale & retail | 2026 |
| More Margin Ltd | Professional & scientific | 2009 |
| More Margin Solutions Limited | Information & communication | 2014 |
| More Than a Roof Ltd | Hospitality | 2022 |
| Moreton Road North Flats Management Company Limited | Real estate | 2010 |
| Morgan Corporation Ltd | Manufacturing | 2019 |
| Morgan DE Vere & Partners LLP | | 2010 |
| Morgan Wiseman Solicitors Ltd | Professional & scientific | 2017 |
| Morix Properties Ltd | Real estate | 2023 |
| Morley Contracts Ltd | Administrative & support | 2025 |
| Morning Till Night Ltd | Wholesale & retail | 2018 |
| Morogom UK Ltd | Hospitality | 2023 |
| Morris Gordon Limited | Construction | 1987 |
| Morrison Plastering Ltd | Construction | 2016 |
| MOS Eisley Cantina Ltd | Hospitality | 2025 |
| MOS Shop Ltd | Wholesale & retail | 2026 |
| MOS Transport Ltd | Transport & logistics | 2025 |
| Mosa Trades Limited | Wholesale & retail | 2025 |
| Moscal Construction Ltd | Manufacturing | 2023 |
| Mossbank Property Development Limited | Real estate | 2024 |
| Mossbank Property Limited | Real estate | 2022 |
| MOT Luton Limited | Wholesale & retail | 2024 |
| MOT Masterz Limited | Wholesale & retail | 2025 |
| Mota Windows & Doors Ltd | Construction | 2025 |
| Motag Care Ltd | Administrative & support | 2026 |
| Motaworx Limited | Wholesale & retail | 2024 |
| Motcomb Street Limited | Real estate | 2021 |
| Motec Limited | Wholesale & retail | 2015 |
| Motest Recovery Services Ltd | Transport & logistics | 2021 |
| Mothercap Investment Limited | Real estate | 2018 |
| Motin Writers Ltd | Professional & scientific | 2025 |
| Motion International Group Contracts Limited | Construction | 2017 |
| Motionhaus Ltd | Professional & scientific | 2025 |
| Motor 2 Finance Ltd | Financial services | 2025 |
| Motor Car Parts Services Ltd | Wholesale & retail | 2019 |
| Motor Class Hire Ltd | Administrative & support | 2021 |
| Motor District Ltd | Wholesale & retail | 2025 |
| Motor Mate Luton Ltd | Wholesale & retail | 2025 |
| Motor Parts Buyer Limited | Wholesale & retail | 2017 |
| Motor Spotter (UK) Limited | Wholesale & retail | 2019 |
| Motor Tyres Ltd | Wholesale & retail | 2025 |
| Motor X Assistance Ltd | Wholesale & retail | 2025 |
| Motor Zone Limited | Transport & logistics | 2015 |
| Motorfection Detailing Ltd | Wholesale & retail | 2019 |
| Motorhaus Prestige Ltd | Wholesale & retail | 2026 |
| MOTORHOMES2BUY Limited | Wholesale & retail | 2016 |
| Motoring Centre Luton Ltd | Wholesale & retail | 2011 |
| Motors Heaven Ltd | Extraterritorial | 2019 |
| Motors World Limited | Wholesale & retail | 2020 |
| Motorworld Luton Ltd | Wholesale & retail | 2026 |
| Motoskull Limited | Transport & logistics | 2022 |
| Motrac Limited | Extraterritorial | 2011 |
| Mouhcina Ltd | Professional & scientific | 2018 |
| Moult & Co Ltd | Professional & scientific | 2017 |
| Moulton Residents (Luton) Limited | Households | 1972 |
| Mount Sanford Ltd | Professional & scientific | 2024 |
| Mount Vernon Terrace Residential Care Home Limited | Health & social care | 2015 |
| Mountain DEW Property Company Limited | Construction | 2013 |
| Mountain of Fire and Miracles Ministries Holy Ghost Assembly Ltd | Other services | 2026 |
| Mountvale Projects Ltd | Construction | 2014 |
| Mountview Ventures Ltd | Information & communication | 2018 |
| Mouri Tech Ltd | Information & communication | 2019 |
| Move Line Commercial Ltd | Transport & logistics | 2025 |
| Movemate Logistics Ltd | Transport & logistics | 2024 |
| Movement Innovation Art Ltd | Other services | 2023 |
| Movera Ltd | Wholesale & retail | 2025 |
| Moving Image Luton CIC | Manufacturing | 2024 |
| Moyart Ltd | Real estate | 2024 |
| Moynul Khan IT Ltd | Information & communication | 2023 |
| MP General Building Ltd | Construction | 2016 |