| Lizardstudio Ltd | Information & communication | 2013 |
| Locke & Co Accountants Limited | Professional & scientific | 2022 |
| Lodge Tiling Limited | Construction | 2010 |
| Lolin Metabolic and Diagnostic Services Limited | Health & social care | 2012 |
| London & Southern Hygiene Limited | Administrative & support | 1985 |
| London Contract Flooring Ltd | Construction | 2024 |
| London Girl Limited | Administrative & support | 2009 |
| London International Band Week Ltd | Arts & recreation | 2019 |
| London RD Tonbridge Limited | Hospitality | 2024 |
| London Runway Ltd | Information & communication | 2018 |
| Lone Orca Ltd | Wholesale & retail | 2025 |
| Lordswell Investments Ltd | Real estate | 2016 |
| Lordswell Services Ltd | Real estate | 2023 |
| Lost BOY Events Ltd | Hospitality | 2026 |
| Lotsawa House CIC | Professional & scientific | 2022 |
| Lovelace Pilates Limited | Administrative & support | 2009 |
| Lovinglyuk Ltd | Wholesale & retail | 2020 |
| LS ODY Consulting Limited | Professional & scientific | 2021 |
| LSB Security Consulting Ltd | Administrative & support | 2020 |
| Lucid Code Labs Ltd | Information & communication | 2026 |
| Lucid Creative Works Limited | Education | 2021 |
| Luke Turner Plastering Ltd | Construction | 2010 |
| Lulu&Ben Limited | Construction | 2014 |
| Lumi Silver Ltd | Wholesale & retail | 2013 |
| Lupaia Consulting Limited | Professional & scientific | 2014 |
| Luxe Nails Bar Ltd | Other services | 2022 |
| Lymley Children C.I.C. | Education | 2020 |
| M and RO Plus Limited | Construction | 2022 |
| M R Garden Services Ltd | Administrative & support | 2003 |
| M.K Auto Solutions Ltd | Wholesale & retail | 2021 |
| M.M Principe Limited | Hospitality | 2026 |
| MA TW Learning Centre LLP | | 2024 |
| Macdonaldbegeman Limited | Professional & scientific | 2016 |
| Macey Properties Limited | Administrative & support | 2001 |
| Mackenzie Sampson Ltd | Real estate | 2022 |
| Macs Property Solutions Ltd | Administrative & support | 2016 |
| Maddisys Limited | Information & communication | 2004 |
| Magic Decorating Ltd | Construction | 2017 |
| Magic Marc R Limited | Administrative & support | 2005 |
| Magus Education Ltd | Administrative & support | 2016 |
| Maison Patina Ltd | Manufacturing | 2021 |
| Makwawa Malawi Limited | Other services | 2002 |
| Malachite Consulting Ltd | Professional & scientific | 2019 |
| Mallard Drinks Limited | Professional & scientific | 2025 |
| MAN Without a Shadow Limited | Administrative & support | 2016 |
| Manek Mobile Ltd | Wholesale & retail | 2026 |
| Manor Place (Steel Cross) Management Limited | Households | 2018 |
| Manorcroft Estates Limited | Real estate | 2010 |
| Mansell Mctaggart Crowborough Limited | Real estate | 2011 |
| Manttra UK Limited | Manufacturing | 2017 |
| Marceloanciano Limited | Information & communication | 2021 |
| Marchwood Park Limited | Construction | 2014 |
| Marens (Marine Renewables) UK Ltd | Professional & scientific | 2022 |
| Marino & Co Ltd | Professional & scientific | 2014 |
| Marino BBL & Co Ltd | Professional & scientific | 2022 |
| Mark Education Trust | Education | 2012 |
| Mark Grunwell Associates Ltd | Financial services | 2014 |
| Mark Recreation Limited | Education | 2022 |
| Market Place Management (Goudhurst) Limited | Households | 2018 |
| Marlborough Court Freeholders Limited | Real estate | 2008 |
| Marlborough Court Management (Westerham) RTM Company Limited | Real estate | 2003 |
| Marley Industries Limited | Real estate | 2019 |
| Martian Media Ltd | Information & communication | 2014 |
| Martin Cranfield Associates Ltd | Professional & scientific | 2004 |
| Marwil Consultancy Limited | Administrative & support | 2015 |
| MAS Property Solutions Limited | Real estate | 2016 |
| Mathieson Associates Ltd | Professional & scientific | 2017 |
| Matt Pickett Property Limited | Real estate | 2025 |
| Matthew Pattenden Ltd | Administrative & support | 2019 |
| Maximum Talent Management Ltd | Professional & scientific | 2025 |
| Maxwell Adam Ltd | Wholesale & retail | 2018 |
| Mayan Security Ltd | Administrative & support | 2016 |
| Mayfair Somerset Limited | Construction | 2018 |
| Mayfield Osteopaths & Holistic Therapies Limited | Health & social care | 2024 |
| Mbmobilemechanic Ltd | Wholesale & retail | 2025 |
| Mcnaughtons Landscaping Limited | Administrative & support | 2021 |
| Mcnaughtons Limited | Construction | 2025 |
| Mdpr Cornwall Ltd | Hospitality | 1995 |
| Melbourne Brew Co Limited | Hospitality | 2020 |
| Melchy & Nogg Limited | Professional & scientific | 2025 |
| Melpherion Technologies Ltd | Professional & scientific | 2024 |
| Memento Jocelyn Limited | Extraterritorial | 2002 |
| Merakai Brewing Co Ltd | Manufacturing | 2019 |
| Meraki Living Limited | Real estate | 2016 |
| Mercator Aviation Ltd | Administrative & support | 2014 |
| Mercator Digital Ltd | Administrative & support | 2008 |
| Mercator Group LLP | | 2019 |
| Mercator IT Consulting LLP | | 2013 |
| Mercator IT Solutions Limited | Information & communication | 2006 |
| Mercator Limited | Real estate | 2017 |
| Mercator Umbrella Solutions Limited | Administrative & support | 2017 |
| Mergaliyev Classical Ballet Ltd | Arts & recreation | 2023 |
| Merlin Flooring and Tiling Ltd | Construction | 2016 |
| Merlin Lazer Ltd | Manufacturing | 1997 |
| MF Carpentry Ltd | Construction | 2018 |
| Mfcss Limited | Hospitality | 2024 |
| MGR Auto Services (UK) Limited | Wholesale & retail | 2010 |
| Michael Brooker Estate Agents Limited | Real estate | 2021 |
| Mida Financial Solutions Limited | Financial services | 2014 |
| Midwifery Unit Network Limited | Education | 2019 |