| Moon Watcher Entertainment Limited | Information & communication | 2007 |
| Moonachie Associates Ltd | Professional & scientific | 2016 |
| Moonachie Investments Ltd | Other services | 2022 |
| Moongaze Creative Ltd | Information & communication | 2020 |
| Moor Lane Maulden Management Company Ltd | Households | 2021 |
| Moore Capital Holdings Ltd | Professional & scientific | 2025 |
| Moore Holmes Properties Limited | Real estate | 2023 |
| Moorhouse Compliance Management Ltd | Professional & scientific | 2025 |
| Moorside FJ Cottontops Limited | Wholesale & retail | 2020 |
| Mopzilla Ltd | Administrative & support | 2025 |
| Mordem Operations Limited | Construction | 2012 |
| More 4 Property Ltd | Real estate | 2017 |
| More Choice Financial Ltd | Financial services | 2006 |
| More IQ Group Limited | Information & communication | 2021 |
| More IQ Limited | Information & communication | 2021 |
| Moretaine Beans Ltd | Hospitality | 2025 |
| Moretaine Investments Ltd | Real estate | 2023 |
| Morgan Mobility Lift Services Ltd | Manufacturing | 2022 |
| Morgan Sewell Limited | Manufacturing | 2019 |
| Morley Motion Pictures Limited | Information & communication | 2017 |
| Morris Property Investments Ltd | Real estate | 2019 |
| Morrocan Bliss Ltd | Health & social care | 2025 |
| Mortak Solutions Ltd | Manufacturing | 2021 |
| Mortgage Adviser Directory Ltd | Information & communication | 2023 |
| Mortimer Asset Management Limited | Financial services | 2025 |
| Mosaic Board Printers Limited | Manufacturing | 1996 |
| Moseri Ltd | Manufacturing | 2024 |
| Moss MOT Ltd | Wholesale & retail | 2025 |
| Moss&Ivy Florist Ltd | Wholesale & retail | 2025 |
| Moster Ltd | Administrative & support | 2018 |
| Motaquip Limited | Wholesale & retail | 2014 |
| Mothers-Daughters Vineyard Ministries CIC | Education | 2026 |
| Moti Properties Limited | Real estate | 2026 |
| Motif Holdings Group Limited | Financial services | 2020 |
| Motif Sports Limited | Information & communication | 2022 |
| Motif Studios Limited | Information & communication | 2019 |
| MOTION5 Ltd | Administrative & support | 2025 |
| Motionkind CIC | Information & communication | 2025 |
| Moto Mavericks Junior Motocross Limited | Arts & recreation | 2023 |
| Motolab Ltd | Wholesale & retail | 2021 |
| Motorhouse (Beds) Ltd | Wholesale & retail | 2023 |
| Motorport Ltd | Wholesale & retail | 2025 |
| Motors Hub Limited | Wholesale & retail | 2019 |
| Motors Master Ltd | Wholesale & retail | 2024 |
| Motorsafe Rescue Ltd | Wholesale & retail | 2025 |
| Motosolutions Limited | Wholesale & retail | 2004 |
| Motya Limited | Professional & scientific | 2022 |
| Moulin Limited | Administrative & support | 2002 |
| Moulton Lawn House Ltd | Real estate | 2021 |
| Mountain ASH (Saundersfoot) Limited | Real estate | 2020 |
| Mountain Buggy Limited | Wholesale & retail | 2009 |
| Mountcare UK Limited | Administrative & support | 2026 |
| Mounter Carpets & Flooring Limited | Wholesale & retail | 2005 |
| Mouve Consulting Ltd | Professional & scientific | 2026 |
| Move Events Official UK Ltd | Administrative & support | 2025 |
| Move With EZE Clinic Ltd | Other services | 2026 |
| Move-Shine Limited | Transport & logistics | 2020 |
| Movefit Pilates Ltd | Health & social care | 2024 |
| Moveo UK Ltd | Transport & logistics | 2009 |
| Movertop Ltd | Transport & logistics | 2023 |
| Movie Figures Limited | Wholesale & retail | 2013 |
| Moving Machines Limited | Wholesale & retail | 2024 |
| MOW With Grace C.I.C. | Administrative & support | 2025 |
| Mow-Sure Training Ltd | Professional & scientific | 2018 |
| Mowbray Financial Limited | Professional & scientific | 2008 |
| Mowsbury Car Sales Limited | Wholesale & retail | 2025 |
| Mowsbury Investments Limited | Real estate | 2024 |
| Moxon Nightingale Limited | Real estate | 2020 |
| MP Coaching Systems Ltd | Administrative & support | 2019 |
| MP Labels Ltd | Manufacturing | 2021 |
| MP Logictics Limited | Transport & logistics | 2025 |
| MP Mixer Hire Ltd | Transport & logistics | 2023 |
| Mp-Tec UK Ltd | Manufacturing | 2025 |
| Mpalahealthcare Limited | Health & social care | 2025 |
| Mpathy Therapy Ltd | Health & social care | 2020 |
| MPD Property Limited | Real estate | 2022 |
| MPH Building Services Limited | Construction | 2016 |
| MPH HR Consultancy Ltd | Professional & scientific | 2024 |
| MPH Property Limited | Real estate | 2018 |
| MPP (Bedford South) Ltd | Administrative & support | 2022 |
| MPP (Bedford) Ltd | Other services | 2020 |
| MQ Mobile Tyres Limited | Wholesale & retail | 2012 |
| MR Combi Limited | Professional & scientific | 2006 |
| MR Combi Sales Limited | Information & communication | 2009 |
| MR EAR Nose Throat Ltd | Health & social care | 2020 |
| MR Property Invest Ltd | Real estate | 2025 |
| MR Property Maintenance Limited | Construction | 2012 |
| MR Woolley Ltd | Information & communication | 2018 |
| MRB Building Ltd | Construction | 2025 |
| MRC Planning Limited | Other services | 2015 |
| MRE Switch Ltd | Information & communication | 2025 |
| Mrfr Homes Ltd | Real estate | 2025 |
| MRJ Trading Limited | Administrative & support | 2007 |
| Mrktplace Ltd | Administrative & support | 2025 |
| MRN Medeleanu Ltd | Construction | 2017 |
| MRR Marius Ltd | Transport & logistics | 2021 |
| MRS T Weddings Ltd | Administrative & support | 2022 |
| MRV Investment Group Ltd | Wholesale & retail | 2022 |
| MRX Construction Group Limited | Construction | 2026 |
| MRX Fixers Ltd | Construction | 2021 |