| MTM Property Sourcing Ltd | Real estate | 2025 |
| Muddy Boots Nursery (Hampshire) Ltd | Education | 2024 |
| Muddy Wheels 4 Festival Thrills Ltd | Administrative & support | 2026 |
| Mulanda Training and Consulting Limited | Administrative & support | 2025 |
| Mulberry Asset Management Ltd | Real estate | 2018 |
| Mulberry Contracting Ltd | Construction | 2019 |
| Mulberry Surveying Limited | Professional & scientific | 2024 |
| Multi Trade Services (Havant) Ltd | Construction | 2026 |
| Multiarte Limited | Information & communication | 2014 |
| Multicolours Painters & Decorators Limited | Construction | 2015 |
| Multiform Design Solutions Limited | Information & communication | 2006 |
| Mummyfit (Bradford & Calderdale) Ltd | Arts & recreation | 2024 |
| Munich Automotive Ltd | Wholesale & retail | 2026 |
| Murktweaks Ltd | Information & communication | 2022 |
| Murphy Holdings Limited | Professional & scientific | 2003 |
| Murray Mcintosh O'Brien | | 1997 |
| Murray Simons Medical Services Limited | Health & social care | 2012 |
| Murray TCC Limited | Wholesale & retail | 1984 |
| Muscle in Limited | Wholesale & retail | 1998 |
| Mushavi Private Limited | Health & social care | 2015 |
| MV Living Limited | Real estate | 2024 |
| Mvest Limited | Real estate | 2018 |
| MW Legal Ltd | Professional & scientific | 2022 |
| Mwogier Ltd | Information & communication | 2024 |
| My Bambino Ltd | Wholesale & retail | 2017 |
| My Dog Sighs Limited | Arts & recreation | 2015 |
| My Gym in a Box Ltd | Wholesale & retail | 2021 |
| My Next Office Ltd | Real estate | 2019 |
| My Online Pharmacy Limited | Wholesale & retail | 2024 |
| My Property (Southern) Ltd | Construction | 2024 |
| My Retro Computer Ltd | Manufacturing | 2014 |
| My Telecom Group Ltd | Information & communication | 2016 |
| My Yarnery Ltd | Wholesale & retail | 2016 |
| Mydj Limited | Arts & recreation | 2022 |
| Mystic Nest Limited | Wholesale & retail | 2024 |
| Mystudentpad Limited | Real estate | 2011 |
| N & J Plant Hire Ltd | Administrative & support | 2015 |
| N & MK Ltd | Education | 2018 |
| N and P Touring Ltd | Professional & scientific | 2018 |
| N B Paint Limited | Construction | 2002 |
| N D Solutions Southern Ltd | Construction | 2025 |
| N Gooch Engineering Ltd | Professional & scientific | 2017 |
| N L Gates Limited | Construction | 2013 |
| N-Force Legal Limited | Other services | 2014 |
| N.B.Powell Ltd | Transport & logistics | 2019 |
| N2 (UK) Ltd | Professional & scientific | 2013 |
| N86 Include-Ed Limited | Education | 2024 |
| Nails by THI Limited | Other services | 2025 |
| Nairdwood Limited | Financial services | 2018 |
| NAL21 Limited | Transport & logistics | 2021 |
| Nalyn Ltd | Information & communication | 2019 |
| Nance Maccabe Holdings Limited | Professional & scientific | 2017 |
| Nanomath UK Limited | Professional & scientific | 2023 |
| NAO Consultancy Ltd | Information & communication | 2022 |
| NAS Corporate Limited | Financial services | 2023 |
| NAS Corporation Limited | Transport & logistics | 2012 |
| Nash Creative Media Ltd | Information & communication | 2020 |
| Nason Associates Limited | Professional & scientific | 2017 |
| Nassau Investments Limited | Financial services | 2015 |
| Natan Consulting Ltd | Information & communication | 2017 |
| Nathan Butler Consulting Limited | Professional & scientific | 2021 |
| Nathaniel Johnson Limited | Construction | 2019 |
| National Regional Property Group Limited | Professional & scientific | 2015 |
| NATIONAL365 Limited | Transport & logistics | 2022 |
| Nations Light Ministries | Other services | 2007 |
| Nationwide Law Limited | Professional & scientific | 2025 |
| Natural Stone and Porcelain Ltd | Construction | 2020 |
| Naturally Curious Childcare Limited | Health & social care | 2020 |
| Nautilus Search Limited | Administrative & support | 2026 |
| Navarr Ltd | Wholesale & retail | 2026 |
| Nb-Iot Ltd | Manufacturing | 2023 |
| NBS Customs Ltd | Transport & logistics | 2025 |
| Ncb-Qs Ltd | Professional & scientific | 2023 |
| Ncgcare Ltd | Health & social care | 2018 |
| Nchanga Limited | Arts & recreation | 2020 |
| NCN Parcel Network Limited | Transport & logistics | 2025 |
| NE Group Holdings Limited | Professional & scientific | 2018 |
| NE Highways Consultancy Ltd | Administrative & support | 2022 |
| Neal Motorcycle Logistics Ltd | Transport & logistics | 2024 |
| Near ME Holdings Ltd | Financial services | 2025 |
| Near ME Plumbing and Heating Ltd | Construction | 2023 |
| Nedumparambil Ltd | Health & social care | 2015 |
| Neil Bull Limited | Construction | 2002 |
| Neil Doyle Consulting Limited | Professional & scientific | 2015 |
| Neoci Ltd | Administrative & support | 2020 |
| Neruda Capital Ltd | Other services | 2024 |
| Network Group Events Limited | Professional & scientific | 2012 |
| Network Group Management Limited | Administrative & support | 2016 |
| Netzero Innovations Limited | Professional & scientific | 2019 |
| NEU Practice Limited | Health & social care | 2017 |
| NEU Retreats Limited | Health & social care | 2023 |
| Neurodiagnosis Ltd | Health & social care | 2023 |
| Neuroinclusion Works Ltd | Information & communication | 2022 |
| New Down Developments Limited | Construction | 2024 |
| New Hayven Merchant Partners LP | | 2024 |
| New Holdings Limited | Transport & logistics | 2019 |
| New Image Aesthetics Ltd | Health & social care | 2017 |
| New Image Facilities Ltd | Construction | 2014 |
| New London Equity Limited | Financial services | 2021 |
| Newcole Limited | Professional & scientific | 2005 |