| Muinin Consulting Group Limited | Information & communication | 2023 |
| Muinin Equity Partners Limited | Financial services | 2022 |
| Muir Oesterhus Ltd | Real estate | 2023 |
| Mujtaba Solutions Limited | Professional & scientific | 2013 |
| Mukedo Limited | Real estate | 2020 |
| Mulberry Construction Group Limited | Construction | 2023 |
| Mulberry Contracts London Limited | Construction | 2017 |
| Mulberry First Limited | Real estate | 2019 |
| Mulberry Property & Interiors Limited | Real estate | 2024 |
| Mulberry Property Group Ltd | Real estate | 2020 |
| Mulbury Homes (Greg Street) Limited | Construction | 2016 |
| Mulch Leeds CIC | Administrative & support | 2026 |
| Mulhern & Hickey Limited | Wholesale & retail | 1991 |
| Mulik Ltd | Real estate | 2025 |
| Mullaco Cash & Carry Ltd | Wholesale & retail | 2018 |
| Mullaco Foods Ltd | Wholesale & retail | 2024 |
| Mulroy Antiques Limited | Wholesale & retail | 2015 |
| Mulroy Provincial Limited | Wholesale & retail | 2015 |
| Mulservegroup Ltd | Administrative & support | 2025 |
| Multaqa Cafe Ltd | Hospitality | 2024 |
| Multi Cleaning Limited | Health & social care | 2025 |
| Multi Drinks Ltd | Wholesale & retail | 2024 |
| Multi Facilities Provision ( MFP UK ) Limited | Administrative & support | 2017 |
| Multi Trade Operations Ltd | Construction | 2025 |
| Multi-Color Cwmbran UK Limited | Manufacturing | 1999 |
| Multi-Color Daventry England Ltd | Manufacturing | 1987 |
| Multi-Color UK Holdings 2 Limited | Financial services | 2017 |
| Multi-Line Building Contractor Ltd | Manufacturing | 2008 |
| Multi-Treatments Limited | Construction | 2005 |
| Multibright Limited | Real estate | 1993 |
| Multicare Electronics Limited | Other services | 2000 |
| Multicode Limited | Information & communication | 2018 |
| Multieuro Limited | Hospitality | 1991 |
| Multifaceted Online Mart Ltd | Wholesale & retail | 2024 |
| Multiflight Limited | Transport & logistics | 1994 |
| Multihaz Ltd | Information & communication | 2022 |
| Multilinea Ltd | Extraterritorial | 2017 |
| Multilingual Services Limited | Administrative & support | 1992 |
| Multisol Europe Limited | Transport & logistics | 2004 |
| Multisol Group Limited | Professional & scientific | 2003 |
| Multisol Limited | Manufacturing | 1968 |
| Multisped Ltd. | Transport & logistics | 2017 |
| Multiwallet Ltd | Professional & scientific | 2026 |
| Multiwebhost Ltd | Extraterritorial | 2020 |
| Mumbai Beverages Limited | Hospitality | 2026 |
| Mumbai Kitchen Garforth Limited | Hospitality | 2016 |
| Mumbai of Pontefract Ltd | Hospitality | 2025 |
| Mumbai of Rodley Ltd | Hospitality | 2025 |
| Mumbai of Swillington Ltd | Hospitality | 2026 |
| Mumbi & Co Ltd | Wholesale & retail | 2026 |
| Mummy Gummy Ltd | Wholesale & retail | 2025 |
| Mummyfit (NW Leeds & Bradford) Ltd | Arts & recreation | 2020 |
| Mummyfit (South Leeds and Wakefield) Ltd | Arts & recreation | 2025 |
| Mumtaz and Gulzar Consultants Ltd | Professional & scientific | 2020 |
| Mumtaz Leeds Limited | Hospitality | 2007 |
| Munaliam Private Limited | Health & social care | 2019 |
| Munch Event Catering Ltd | Hospitality | 2024 |
| Munch Express@Leeds Ltd | Hospitality | 2025 |
| Munchbox (Leeds) Ltd | Hospitality | 2018 |
| Munchies 24-7 Ltd | Hospitality | 2023 |
| Munchies Cafe Bar Ltd | Hospitality | 2025 |
| Munchkins Limited | Health & social care | 2026 |
| Mund Consulting Ltd | Information & communication | 2010 |
| Mundane Delivery Ltd | Transport & logistics | 2026 |
| Mungano CIC | Education | 2024 |
| Muninn Protection Services Ltd | Administrative & support | 2023 |
| Munir Khattak Limited | Wholesale & retail | 2025 |
| Munkel Investment Ltd | Real estate | 2023 |
| Munna Ltd | Professional & scientific | 2019 |
| Munnch NGM Ltd | Professional & scientific | 2024 |
| Munogona Mwari Limited | Health & social care | 2015 |
| Muny Momentum Ltd | Transport & logistics | 2025 |
| Mupeto Healthcare Ltd | Wholesale & retail | 2022 |
| Muphil Limited | Transport & logistics | 2023 |
| Mura Studio Ltd | Professional & scientific | 2016 |
| Murcia Homes Ltd | Real estate | 2020 |
| Murdoch Logistic Services Ltd | Administrative & support | 2011 |
| Mureed Link Travel and Tourism Ltd | Administrative & support | 2026 |
| Murga Solutions Limited | Information & communication | 2025 |
| Murgatroyd's Salt & Chemical Company Limited | Professional & scientific | 1947 |
| Murmur Live Limited | Arts & recreation | 2023 |
| Murphy Utilities Limited | Construction | 2011 |
| Murray & Joy Consultants Ltd | Professional & scientific | 2024 |
| Murray Hill Engineering Ltd | Professional & scientific | 2025 |
| Murray Hurst Interiors Limited | Professional & scientific | 2010 |
| Murray Johnstone Private Acquisitions Partnership II 'C' | | 1996 |
| Murray Johnstone Private Acquisitions Partnership II 'D' | | 1996 |
| Murray Johnstone Private Acquisitions Partnership II `B' | | 1996 |
| Murray Johnstone Private Acquisitions Partnership Ii'A' | | 1996 |
| Murray Oncology Solutions Limited | Health & social care | 2026 |
| Murray Property Group Limited | Financial services | 2017 |
| Murrells Bakery Ltd | Hospitality | 2021 |
| Murri Marketing Limited | Professional & scientific | 2015 |
| Murrielle Ltd | Manufacturing | 2018 |
| Murs Private Ltd | Real estate | 2025 |
| Murse Property Limited | Real estate | 2025 |
| Murtaza Holdings Ltd | Financial services | 2022 |
| Murtaza Invest Ltd | Real estate | 2024 |
| Murton White House Steading Management Limited | Real estate | 2008 |
| Murugan Ilanthalir Limited | Real estate | 2026 |