| Moore Home Care Limited | Health & social care | 2024 |
| Mooreacrestouringandglamping Ltd | Hospitality | 2023 |
| Moorends Barber Shop Ltd | Other services | 2023 |
| Moores Bakery Limited | Manufacturing | 2003 |
| Moores Consulting Limited | Information & communication | 2026 |
| Moores Properties and Rentals Limited | Real estate | 2021 |
| Moorfield Cottage Creations Ltd | Hospitality | 2024 |
| Moorfield Homes Limited | Construction | 2024 |
| Moorfield Park (Bolsover) Management Company Limited | Households | 2022 |
| Moorgate Design Limited | Professional & scientific | 2023 |
| Moorgate Medical Andrology Limited | Health & social care | 2026 |
| Moorhen Design and Build Limited | Construction | 2023 |
| Moorhouse EC Limited | Arts & recreation | 2020 |
| Moorland Court (Doncaster) Limited | Professional & scientific | 2003 |
| Moorooboorai Ltd | Information & communication | 2010 |
| Moorstone Housing Limited | Real estate | 2009 |
| Mora Medtech UK Ltd | Health & social care | 2017 |
| Moran Paving Limited | Construction | 2023 |
| Morariu Services Ltd | Construction | 2025 |
| More Than a Memory Limited | Information & communication | 2019 |
| More Than Baths Limited | Wholesale & retail | 2007 |
| More Than Dreams Ltd | Information & communication | 2026 |
| More Than ED Independent School Limited | Education | 2020 |
| More Than Safe Ltd | Education | 2025 |
| Morespace Hire Services Limited | Administrative & support | 2008 |
| Morespace Limited | Administrative & support | 1997 |
| Morethan Backoffice Ltd | Administrative & support | 2023 |
| Morgan Dodd Limited | Professional & scientific | 2003 |
| Morgan Health Solutions Limited | Professional & scientific | 2009 |
| Morgan Inns Ltd | Hospitality | 2019 |
| Morgan North Property Hunters Ltd | Real estate | 2026 |
| Morgan TM Ltd | Construction | 2019 |
| Morgan Training & Safety Services Limited | Administrative & support | 2005 |
| Morling Electronics Ltd | Manufacturing | 2015 |
| Morning Batch Bakery Ltd | Extraterritorial | 2026 |
| Morpxheus Ltd | Manufacturing | 2012 |
| Morrell Farming Ltd | Agriculture & fishing | 2024 |
| Morrey Oils Holdings Limited | Transport & logistics | 2017 |
| Morrey Oils Limited | Transport & logistics | 1982 |
| Morris & Beck Limited | Real estate | 2007 |
| Morris & Co. (Handlers) Limited | Wholesale & retail | 1976 |
| Morris Bywater Limited | Wholesale & retail | 1975 |
| Morris Medical Services Ltd | Health & social care | 2025 |
| Morrison Aerospace Limited | Manufacturing | 2010 |
| Mortem Rail Engineering Ltd | Professional & scientific | 2019 |
| Mortgages Re-Mortgages Limited | Financial services | 2003 |
| Mortimore Financial Services LLP | | 2013 |
| Morvella Healthcare Ltd | Extraterritorial | 2026 |
| Morvexis Manufacturing Ltd | Extraterritorial | 2026 |
| Morweth Cottages Limited | Households | 2003 |
| Mosjan Ltd | Transport & logistics | 2017 |
| Moso Real Estate Ltd | Real estate | 2025 |
| Moss Carr Environmental Ltd | Agriculture & fishing | 2018 |
| Moss IS Ltd | Information & communication | 2018 |
| Moss Mortgages Limited | Financial services | 2009 |
| Most Hated Ltd | Wholesale & retail | 2025 |
| Most Wanted Marketing Limited | Professional & scientific | 2008 |
| MOT Works Ltd | Administrative & support | 2023 |
| Motek Portable Products Limited | Professional & scientific | 1978 |
| Motetrans Ltd | Transport & logistics | 2019 |
| Mother Hookers CIC | Arts & recreation | 2025 |
| Motherlinelegalservices Limited | Hospitality | 2014 |
| Motohawk Retail Ltd | Wholesale & retail | 2020 |
| Motor Bundle Ltd | Wholesale & retail | 2013 |
| Motor Chill Ltd | Wholesale & retail | 2019 |
| Motor Cycle Parts Limited | Wholesale & retail | 2013 |
| Motor Lube Limited | Wholesale & retail | 2024 |
| Motor Medics Doncaster Ltd | Wholesale & retail | 2025 |
| Motor Mouth Ltd | Hospitality | 2023 |
| Motorcraft Adventures Developments Ltd | Manufacturing | 2019 |
| Motorcraft Overland Travel Ltd | Administrative & support | 2024 |
| Motorcraft Overlander Accessories Limited | Manufacturing | 2023 |
| Motorcraft Overlander Holdco Limited | Manufacturing | 2024 |
| Motorcycle Guru Limited | Wholesale & retail | 2020 |
| Motorcycle Parts and Spares Limited | Wholesale & retail | 2018 |
| Motorflog Ltd | Wholesale & retail | 2023 |
| Motors 2 Go Limited | Wholesale & retail | 2015 |
| Motorsport Transport Solutions Limited | Other services | 2016 |
| Moults of Shropshire Limited | Wholesale & retail | 2021 |
| Mount Pleasant Inn Repton Limited | Hospitality | 2025 |
| Mountain Consultancy Limited | Professional & scientific | 2023 |
| Mountain Contractors Ltd | Construction | 2015 |
| Mountain Minerals Ltd | Wholesale & retail | 2023 |
| Mouse Park Limited | Agriculture & fishing | 2014 |
| Mousecat Productions Ltd | Extraterritorial | 2013 |
| Movers and Shapers Ltd | Manufacturing | 2024 |
| Movida Go Limited | Hospitality | 2019 |
| Mowatt Property Ltd | Real estate | 2019 |
| Mowbray NO. 2 Ltd | Water & waste | 2001 |
| Mowjoe Garden Services Ltd | Administrative & support | 2024 |
| MOX Capital Limited | Construction | 2020 |
| MOY Properties Limited | Real estate | 2017 |
| Mozza Prime Ltd | Hospitality | 2022 |
| MP Express Ltd | Transport & logistics | 2026 |
| MPA Couriers Ltd | Transport & logistics | 2020 |
| MPA Drivers Ltd | Transport & logistics | 2023 |
| MPA Northstar Transport Ltd | Transport & logistics | 2026 |
| MPC3 Limited | Professional & scientific | 2004 |
| MPG Driving Limited | Education | 2025 |
| MPH Property Solutions Ltd | Real estate | 2025 |