| Momentum Finance Group Construction Limited | Construction | 2024 |
| Momentum Finance Group Investments Limited | Extraterritorial | 2024 |
| Momentum Finance Group Limited | Financial services | 2023 |
| Momentum Finance Group Property Investments Limited | Real estate | 2026 |
| Momentum Finance Group SPV1 Limited | Financial services | 2023 |
| Momentum Finance Group SPV2 Limited | Financial services | 2023 |
| Momentum Finance Group SPV3 Limited | Financial services | 2023 |
| Momentum Fitness UK Ltd | Administrative & support | 2022 |
| Momina Ltd | Health & social care | 2012 |
| Momina Transport Limited | Transport & logistics | 2026 |
| Momme & Wick Ltd | Manufacturing | 2023 |
| Mommy Boba Ltd | Hospitality | 2025 |
| Mommy Thai (Leeds) Ltd | Hospitality | 2018 |
| Mommy Thai Merrion Ltd | Hospitality | 2025 |
| Momo Contrator Ltd | Construction | 2022 |
| Momo Studio Ltd | Professional & scientific | 2020 |
| MON Para Limited | Wholesale & retail | 2025 |
| Mona Aesthetics Leeds Ltd | Other services | 2024 |
| Monalisa Limited | Wholesale & retail | 2025 |
| Monarch Beds Ltd | Manufacturing | 2015 |
| Monarch Chemicals Limited | Wholesale & retail | 1989 |
| Monarch Growth Ltd | Professional & scientific | 2025 |
| Monarch Print Lounge Ltd | Manufacturing | 2025 |
| Monaw Services Ltd | Administrative & support | 2014 |
| Monday at Nine Holdings Limited | Financial services | 2020 |
| Monday at Nine Limited | Administrative & support | 2017 |
| Monde Property Limited | Real estate | 2017 |
| Mondex Property Holdings Ltd | Real estate | 2026 |
| Mondo JET Properties Ltd | Real estate | 2022 |
| Mondo Scripts Ltd | Other services | 2022 |
| Mone Bros. Civil Engineering Limited | Construction | 1984 |
| Mone Brothers Excavations Limited | Mining & quarrying | 1972 |
| Mone Brothers Group Ltd | Financial services | 2017 |
| Mone Brothers Limited | Administrative & support | 1970 |
| Mone Developments 1 LLP | | 2018 |
| Mone Developments 3 LLP | | 2018 |
| Monevo Holdco 2 Limited | Financial services | 2025 |
| Monevo Ipco 1 Limited | Financial services | 2025 |
| Monevo Limited | Financial services | 2008 |
| Monevo Technology Limited | Financial services | 2020 |
| Money Stone Investment Ltd | Construction | 2021 |
| MONEY4YOURMOTORS.COM Limited | Other services | 2015 |
| Moneycents Ltd | Professional & scientific | 2023 |
| Moneytruck Limited | Financial services | 2023 |
| Mongoose Energy Supply Limited | Energy | 2014 |
| Monica Healthcare Limited | Professional & scientific | 2005 |
| Monica Saikia Limited | Professional & scientific | 2019 |
| Monirates Limited | Financial services | 2022 |
| Monitor HUT Ltd | Information & communication | 2023 |
| Monje & Vendavales Ltd | Wholesale & retail | 2024 |
| Monjr Limited | Wholesale & retail | 2016 |
| Monk Buxton Limited | Hospitality | 2007 |
| Monk Fryston Stoves Limited | Wholesale & retail | 2003 |
| Monk Fryston Transport Limited | Transport & logistics | 2016 |
| Monk Fryston Village Shop Limited | Wholesale & retail | 2021 |
| Monkey Mill Limited | Wholesale & retail | 2013 |
| Monkey Minded Ltd | Wholesale & retail | 2025 |
| Monkey Tyres Ltd | Wholesale & retail | 2024 |
| Monkfryston Properties Ltd | Real estate | 2024 |
| Monkgate Court Management Company Limited | Real estate | 1996 |
| Monks Bay Consulting Ltd | Information & communication | 2019 |
| Monks Door Systems Limited | Construction | 2016 |
| Monks Security Systems Ltd. | Administrative & support | 1997 |
| Monkswood Limited | Wholesale & retail | 2017 |
| Monli Caisse Limited | Other services | 2022 |
| Monmill Limited | Real estate | 2016 |
| Monnezza Ltd | Transport & logistics | 2025 |
| Mono Architectural Design Limited | Professional & scientific | 2023 |
| Monodraught Holdings Limited | Financial services | 2017 |
| Monodraught Limited | Manufacturing | 1974 |
| Monodraught Topco Limited | Financial services | 2017 |
| Monolith Opera Limited | Other services | 2021 |
| Monorend Exteriors Ltd | Construction | 2023 |
| Monowide Ltd | Professional & scientific | 2018 |
| Monpeace Ltd | Health & social care | 2025 |
| Monread Lodge Nursing Home Limited | Health & social care | 1995 |
| Monroe Estate Agents (Guiseley) Ltd | Real estate | 2026 |
| Monroe Estate Agents (Yorkshire) Limited | Real estate | 2022 |
| Monroe Estate Agents Ltd | Real estate | 2020 |
| Monroe Land and New Homes Limited | Real estate | 2026 |
| Monroe Lettings and Property Management Ltd | Real estate | 2023 |
| Monsef Limited | Wholesale & retail | 2010 |
| Monster Data Cabling Ltd | Information & communication | 2018 |
| Monster Pet Holdings Ltd | Financial services | 2020 |
| Mont Blanc Guides Limited | Administrative & support | 2005 |
| Montagu Group Limited | Hospitality | 2016 |
| Montagu Property Investment Ltd | Real estate | 2022 |
| Montagu Street Property Limited | Real estate | 2023 |
| Montague Recruitment Ltd | Administrative & support | 2026 |
| Montaldo Consultants Limited | Professional & scientific | 2019 |
| Montana Anaser Limited | Transport & logistics | 2025 |
| Montapex Limited | Administrative & support | 2021 |
| Montford Homes Limited | Construction | 2006 |
| Montgomery & Coupers Ltd | Health & social care | 2010 |
| Montgomery Medical Services Ltd | Health & social care | 2022 |
| Montorio Limited | Administrative & support | 2020 |
| Montoya Sports & Prestige Ltd | Wholesale & retail | 2018 |
| Montpelier Professional (Galloway) Limited | Professional & scientific | 2006 |
| Montpellier Apartments Maintenance Limited | Households | 2008 |
| Montpellier Court Management Ltd | Households | 2023 |