| Montblee Ltd | Wholesale & retail | 2026 |
| Montclare Equities Limited | Other services | 2014 |
| Montclares International Ltd | Transport & logistics | 2018 |
| Montdor Limited | Real estate | 1992 |
| Monteagle Bridge Ltd | Transport & logistics | 2020 |
| Montfleuri Investments Limited | Real estate | 2000 |
| Montrose Avenue Ltd | Real estate | 2021 |
| Montrosehouse London Ltd | Real estate | 2018 |
| Monushka Ltd | Real estate | 2021 |
| Monvera Ltd | Transport & logistics | 2025 |
| Moodswung Online Ltd | Wholesale & retail | 2025 |
| Mooit Ltd | Information & communication | 2016 |
| Moon Island Global Ltd | Energy | 2025 |
| Moon Lghts Ltd | Manufacturing | 2017 |
| Moon Stallion Ltd | Wholesale & retail | 2021 |
| Moonbowbyher Ltd | Wholesale & retail | 2024 |
| Moondance Events Limited | Professional & scientific | 2017 |
| Moondance Music & Video Ltd | Other services | 1999 |
| Moongipa Europe Ltd | Information & communication | 2010 |
| Moongipa Homes Ltd | Real estate | 2021 |
| Moonlight V Limited | Wholesale & retail | 2024 |
| Moonrakers Properties Ltd | Real estate | 2021 |
| Moonrise Management Limited | Real estate | 2020 |
| Moonstars London Services Ltd | Administrative & support | 2022 |
| Moor Tower Ltd | Real estate | 2025 |
| Moore Consulting Engineers Ltd | Professional & scientific | 2020 |
| Moores Property Developments Limited | Construction | 2012 |
| Moorings Care Home Ltd | Health & social care | 2013 |
| Moptop Ltd | Administrative & support | 2025 |
| Moral Cafee Limited | Hospitality | 2026 |
| Mordex Fashions Limited | Manufacturing | 2001 |
| More & More Consultancy Ltd | Professional & scientific | 2019 |
| More Baraka Ltd | Hospitality | 2023 |
| More Civil Engineering Limited | Construction | 2019 |
| More Paperwork Ltd | Real estate | 2020 |
| More Than a Conqueror | Other services | 2016 |
| Morgan Betts Management Ltd | Manufacturing | 2021 |
| Morgan Hall Legal Limited | Other services | 2008 |
| Morgan Hill Solicitors Ltd | Professional & scientific | 2020 |
| Morgan Z.E Ltd | Real estate | 2023 |
| Morgarmac Investment Company Limited | Real estate | 1958 |
| Morji Limited | Wholesale & retail | 2023 |
| Morley Developments Ltd | Construction | 2020 |
| Morley's Cafe Ltd | Hospitality | 2019 |
| Morleys Foods (GB) Limited | Wholesale & retail | 2015 |
| Morleys Fried Chicken Limited | Wholesale & retail | 2015 |
| Morleys Property Development Limited | Administrative & support | 2014 |
| Morning Lane Properties (UK) Limited | Real estate | 2001 |
| Morning Light Initiative CIC | Hospitality | 2026 |
| Morningside Ruskin Ltd | Other services | 2023 |
| Moro Professional Football Coaching Ltd. | Other services | 2007 |
| Moroccan Garden Ltd | Hospitality | 2012 |
| Moroccan Garden Tea House Limited | Hospitality | 2018 |
| Morodeco Ltd | Wholesale & retail | 2013 |
| Morralee Associates Limited | Administrative & support | 2011 |
| Morrin Limited | Information & communication | 2016 |
| Morris Nedd Ltd | Professional & scientific | 2024 |
| Morrissey Formwork & Groundworks Limited | Construction | 2020 |
| Morsecorp Ltd | Information & communication | 2013 |
| Mortar Property Group Ltd | Households | 2025 |
| Mortgage Analyst Limited | Financial services | 2003 |
| Mortgage Capital Limited | Financial services | 2015 |
| Mortimer Homes Ltd | Real estate | 2021 |
| Mortimer Trading Ltd | Real estate | 2016 |
| Morvex Limited | Wholesale & retail | 2026 |
| Mosa Consultant Ltd | Administrative & support | 2026 |
| Mosaic Homes Limited | Real estate | 2021 |
| Mosal Investments Limited | Real estate | 2022 |
| Mosquitco Ltd | Wholesale & retail | 2024 |
| Moss & Glow Ltd | Wholesale & retail | 2026 |
| Mossford Green Limited | Real estate | 2026 |
| Mossmik Ltd | Wholesale & retail | 2021 |
| Mostrad Limited | Financial services | 1991 |
| Mosu Trans Ltd | Transport & logistics | 2015 |
| Motca Limited | Hospitality | 2022 |
| Mother Care East London Ltd | Health & social care | 2024 |
| Mother's Kitchen International Ltd | Wholesale & retail | 2018 |
| Mothers Into Work CIC | Education | 2023 |
| Mothers Into Work Empowered Ltd | Administrative & support | 2025 |
| Mothersisterfriends Ltd | Administrative & support | 2026 |
| Mothersrise Wellness Ltd | Health & social care | 2025 |
| Mothertree Counselling Limited | Health & social care | 2024 |
| Motifz Couture Ltd | Wholesale & retail | 2014 |
| Motion IT Solutions Ltd | Information & communication | 2018 |
| Motion Vehicle Transport Ltd | Transport & logistics | 2025 |
| Motionx Logistics Ltd | Transport & logistics | 2025 |
| Motolend Ltd | Financial services | 2025 |
| Motor Deco Ltd | Wholesale & retail | 2026 |
| Motor Parts VDM Limited | Wholesale & retail | 2026 |
| Motor Pulse Limited | Wholesale & retail | 2026 |
| Motor's Point London Limited | Wholesale & retail | 2024 |
| Motorable Ltd | Wholesale & retail | 2025 |
| Motorexe Ltd | Wholesale & retail | 2019 |
| Motorflow Ltd | Wholesale & retail | 2026 |
| Motoring Mechanism Limited | Wholesale & retail | 2020 |
| Motorsline Ltd | Wholesale & retail | 2017 |
| Mototech London Ltd | Wholesale & retail | 2022 |
| Mototoys Ltd | Wholesale & retail | 2018 |
| Motrans Haulage Limited | Transport & logistics | 2019 |
| Moul Pharm Ltd | Wholesale & retail | 2024 |