| LV Hospitality Group Ltd. | Hospitality | 2018 |
| LW Cloud Limited | Real estate | 2022 |
| LWP Facilities Limited | Construction | 2005 |
| Lyla and Leche Ltd | Wholesale & retail | 2021 |
| Lynn Roberts Ltd | Other services | 2026 |
| M & S Carpet & Flooring Ltd | Construction | 2024 |
| M & S Carpets & Flooring LLP | | 2007 |
| M and M Scaffolding Ltd | Construction | 2021 |
| M Moloney Consulting Ltd | Information & communication | 2026 |
| M O R Environmental Limited | Professional & scientific | 2014 |
| MA Chaudhry Ltd | Health & social care | 2024 |
| Macaw Property Holdings Ltd | Real estate | 2017 |
| Maclean Design & Build Ltd | Construction | 2022 |
| Macphil Limited | Health & social care | 2014 |
| Madison Black Ltd | Arts & recreation | 2025 |
| Madleigh Services Limited | Professional & scientific | 2017 |
| Magnolia Therapy Space Ltd | Health & social care | 2026 |
| Maguire Property Solutions Ltd | Households | 2019 |
| Mahogany Muse Limited | Wholesale & retail | 2025 |
| Mahoney's Pipework Services Ltd | Construction | 2014 |
| Mahyoshana Limited | Real estate | 2023 |
| Maid to Pictures Limited | Information & communication | 2024 |
| Maistry Consultancy Limited | Information & communication | 2016 |
| Major Trauma Network CIC | Administrative & support | 2014 |
| Makagroup Ltd | Administrative & support | 2021 |
| Make a Move Soulutions Limited | Construction | 2017 |
| Mama’S Party and Play Ltd | Hospitality | 2025 |
| MAN & HAN Investments Limited | Other services | 2015 |
| MAN & HAN Trading Limited | Other services | 2015 |
| MAN LEE Coulsdon Limited | Hospitality | 2022 |
| Manchester Stays Limited | Real estate | 2026 |
| Mantle Land Ltd | Construction | 2025 |
| Maple Care Group Ltd | Health & social care | 2023 |
| Marcj Consulting Limited | Wholesale & retail | 2019 |
| Marcon Construction Limited | Construction | 1996 |
| Marinisha Ltd | Hospitality | 2026 |
| Marshal IT Ltd | Information & communication | 2023 |
| Martco Ltd | Construction | 2019 |
| Martina Produce Ltd | Wholesale & retail | 2022 |
| Mary Convenience Stores Ltd | Other services | 2019 |
| Maryam Aesthetic Clinic Ltd | Other services | 2024 |
| Master Medicine Worldwide Limited | Education | 2025 |
| Mastering Multi-Units Ltd | Professional & scientific | 2013 |
| Maxjack Limited | Professional & scientific | 2024 |
| Maxtrain Limited | Hospitality | 2019 |
| Mayhall Investments Limited | Real estate | 2025 |
| Mayle Investments Ltd | Real estate | 2023 |
| MBR Global Consulting Limited | Other services | 2023 |
| MC Medical Aesthetics Limited | Health & social care | 2020 |
| Mcgrady Properties Limited | Hospitality | 2024 |
| Mean Machine Limited | Wholesale & retail | 2024 |
| Measured Solutions UK Limited | Professional & scientific | 2015 |
| Media & More Marketing Ltd | Professional & scientific | 2021 |
| Medihire Limited | Other services | 2002 |
| Meliorum Limited | Professional & scientific | 2018 |
| Melissa.Assess Ltd | Health & social care | 2020 |
| Memory Mate Ltd | Information & communication | 2024 |
| MEN of Vision Limited | Extraterritorial | 2012 |
| Mensah Property Solutions Limited | Real estate | 2025 |
| Mensah Smart Solutions Limited | Information & communication | 2023 |
| Mercy X Grace Limited | Wholesale & retail | 2023 |
| Metalworks Windows and Doors Limited | Manufacturing | 2025 |
| Metamorphosis Consulting Ltd | Information & communication | 2019 |
| Metropolitan Scaffolding London Ltd | Construction | 2012 |
| MGM Wholesales Ltd | Wholesale & retail | 2019 |
| MGW People Limited | Professional & scientific | 2025 |
| Michaela J White Consulting Ltd | Professional & scientific | 2025 |
| Michal Charemza Limited | Information & communication | 2015 |
| Micro Point Advanced Technology Limited | Wholesale & retail | 2019 |
| Micron Conect Ltd | Wholesale & retail | 2024 |
| Mikado M R Limited | Professional & scientific | 2017 |
| Mikey Doble Racing Limited | Arts & recreation | 2025 |
| Millicent Holdings Ltd | Real estate | 2021 |
| Minal Investments Limited | Construction | 2014 |
| Mindpeople Ltd | Professional & scientific | 2022 |
| Minerva Property Solutions (MPS) Limited | Construction | 2016 |
| Minixtek Ltd | Information & communication | 2025 |
| Mirella Alves Ltd | Information & communication | 2021 |
| Mission Consulting Limited | Professional & scientific | 2001 |
| Mitchell Jenkins Interiors Limited | Construction | 2018 |
| Mithunam Limited | Information & communication | 2026 |
| MJ Leasing Limited | Wholesale & retail | 2013 |
| MJB Building & Roofing Ltd | Construction | 2021 |
| MJC Rentals Limited | Real estate | 2026 |
| MJH Designs Ltd | Professional & scientific | 2025 |
| MJN & Sons Ltd | Construction | 2023 |
| MJS Technology Services Limited | Information & communication | 2020 |
| MKC Capital Limited | Financial services | 2023 |
| MLA Wealth Management Ltd. | Financial services | 2014 |
| MLW Plumbing & Heating Limited | Construction | 2006 |
| Mmtd Limited | Construction | 2016 |
| Mn's Fusion Kitchen Ltd | Hospitality | 2024 |
| Mofa Properties Investment UK Ltd | Financial services | 2024 |
| Momentum Performance AI Ltd | Information & communication | 2025 |
| Monigold Ltd | Administrative & support | 2012 |
| Monika Hofmann Aesthetic Ltd | Education | 2025 |
| Moose Munch Limited | Information & communication | 2008 |
| Morfi Design Ltd | Professional & scientific | 2019 |
| Mosaic Consultancy Ltd | Professional & scientific | 2026 |
| Movex Limited | Transport & logistics | 2025 |