| Milton Kebab Limited | Hospitality | 2018 |
| Miltril Ltd | Administrative & support | 2020 |
| Mindshiftworkshop Ltd | Arts & recreation | 2026 |
| Minutego Grocery Limited | Wholesale & retail | 2024 |
| Miran Cash & Carry Ltd | Wholesale & retail | 2024 |
| Miros Grill Limited | Hospitality | 2025 |
| Mirt (London) Ltd | Construction | 2018 |
| Missprint Limited | Wholesale & retail | 2007 |
| Mist Cafe Bistro Ltd | Hospitality | 2023 |
| Mister Trades Limited | Other services | 2015 |
| Mjcopywriting Limited | Arts & recreation | 2008 |
| MJD Controls Limited | Construction | 2018 |
| Mjett Limited | Real estate | 2016 |
| MJS Lettings Limited | Real estate | 2020 |
| MJS Locks and Carpentry Ltd | Construction | 2020 |
| MJW Property Sourcing Limited | Administrative & support | 2023 |
| MJW Property Staging Ltd | Professional & scientific | 2025 |
| MKA Asset Management Limited | Real estate | 2024 |
| MKA Coffee Ltd | Hospitality | 2024 |
| MKC Payroll Ltd | Administrative & support | 2025 |
| ML Product Distribution Limited | Wholesale & retail | 2023 |
| MMA Fortune Ltd | Real estate | 2020 |
| MNA Agri Limited | Wholesale & retail | 2019 |
| Mnsq (Yole) Ltd | Hospitality | 2021 |
| Mobile Bar Ltd | Hospitality | 2023 |
| Mobility Extra Solutions Limited | Wholesale & retail | 2022 |
| Modern Signs (London) Limited | Administrative & support | 2021 |
| Monarchy Barbering Ltd | Other services | 2024 |
| Moneyhut Ltd | Other services | 2023 |
| Monkhams Hall Property Company Limited | Professional & scientific | 1967 |
| Montessori Book Ltd | Manufacturing | 2019 |
| Moondew Ltd | Information & communication | 2020 |
| Moore Pressure Washing Limited | Administrative & support | 2025 |
| Moorehire Limited | Administrative & support | 2002 |
| More Than This Collective Ltd | Health & social care | 2026 |
| Morleys Holdings Ltd | Construction | 2025 |
| Mortona Limited | Construction | 2000 |
| Moscal Ltd | Construction | 2018 |
| Motor & Taxi Ltd | Transport & logistics | 2024 |
| Motorvation Bishop's Stortford Limited | Wholesale & retail | 2003 |
| Mount Toros Resource Group Limited | Wholesale & retail | 2025 |
| Movement SEO Ltd | Professional & scientific | 2019 |
| MOY Barbers Limited | Other services | 2019 |
| MP Real Estate (Investment) Limited | Extraterritorial | 2018 |
| MP Real Estate (Retail) Limited | Real estate | 2018 |
| MP Real Estate Limited | Professional & scientific | 2012 |
| MPL Capital Limited | Financial services | 2006 |
| Mpower Technical College Ltd | Professional & scientific | 2013 |
| MPS Properties Maintenance Ltd | Real estate | 2026 |
| Mrandmrsmuscle Properties Ltd | Real estate | 2023 |
| MS Mechanical Services Ltd | Construction | 2018 |
| MS Medical Aesthetics & Academy Ltd | Health & social care | 2026 |
| MSD Cafe Ltd | Hospitality | 2025 |
| MSY Capital Ltd | Real estate | 2026 |
| Mudcat Games Ltd | Information & communication | 2025 |
| Mueller Cabinet Makers Limited | Manufacturing | 2022 |
| Muga Rosado Ltd | Hospitality | 2019 |
| Muksha (UK) Limited | Wholesale & retail | 2014 |
| Mula Media Group Ltd | Professional & scientific | 2025 |
| Mulberry Solutions Limited | Households | 2011 |
| Muscleup Fitness Limited | Arts & recreation | 2025 |
| Muzo Mobile Barber Ltd | Other services | 2018 |
| MW Utility Solutions Limited | Construction | 2022 |
| MWA Retail Ltd | Wholesale & retail | 2017 |
| My Advisor Ltd | Professional & scientific | 2018 |
| My Choice Limited | Professional & scientific | 2023 |
| My Energy Game Ltd | Education | 2020 |
| My Idea Shed Ltd | Professional & scientific | 2020 |
| Myddelton Foods Limited | Wholesale & retail | 2021 |
| Myitguyuk Ltd | Wholesale & retail | 2022 |
| Myplanet Plumbing and Heating Ltd | Construction | 2022 |
| Myth Electric Limited | Extraterritorial | 2022 |
| N Harris Consultants Ltd | Professional & scientific | 2009 |
| N L Groundwork Ltd | Construction | 2016 |
| N Line Services Limited | Construction | 2011 |
| N&D Ventures Limited | Real estate | 2023 |
| N&J Fame Limited | Real estate | 2024 |
| N&L Distribucion Ltd | Information & communication | 2019 |
| N.F. Plastering Ltd | Construction | 2016 |
| N.Jones Joinery Limited | Manufacturing | 2018 |
| N1 Concrete MIX Ltd | Manufacturing | 2026 |
| N18 Food and Wines Limited | Wholesale & retail | 2013 |
| Nafets Ltd | Other services | 2025 |
| Naija Limited | Construction | 2019 |
| Nail Care TP Ltd | Other services | 2022 |
| Naini Limited | Professional & scientific | 2018 |
| Naivette Services Limited | Construction | 2000 |
| Nakupenda Limited | Information & communication | 2025 |
| Nannie Annie's Kitchen Ltd | Hospitality | 2025 |
| Naomi Chika Ltd | Professional & scientific | 2023 |
| Narisa Therapy & Massage Ltd | Other services | 2026 |
| National Law Limited | Administrative & support | 2021 |
| Natural Fruit & VEG Ltd | Wholesale & retail | 2018 |
| Naxos Headbase Ltd | Real estate | 2021 |
| NAZ Electronics Limited | Other services | 2025 |
| Nazar Cambridge Ltd | Real estate | 2025 |
| Naze Pizza Ltd | Hospitality | 2025 |
| Nazeing Investments Ltd | Real estate | 2018 |
| Nazeing Motors Ltd | Wholesale & retail | 2026 |
| Nazeing Self Storage Ltd | Real estate | 2026 |