| London International Imports Limited | Wholesale & retail | 1992 |
| London Most Limited | Wholesale & retail | 2005 |
| London Restorers Limited | Manufacturing | 2004 |
| London Rocks Limited | Arts & recreation | 1998 |
| London School of Business Management Ltd | Administrative & support | 2004 |
| London Star Music School Ltd | Education | 2017 |
| London Surfacing Company Limited | Construction | 1971 |
| London Urology Health Ltd | Health & social care | 2023 |
| Londonday Limited | Real estate | 1979 |
| Lone Giraffe Consulting Limited | Professional & scientific | 2025 |
| Lonepalm Limited | Information & communication | 1987 |
| Lonergan Civil Engineering Limited | | 1987 |
| Longacre Place Residents' Association Limited | Households | 1970 |
| Longford (Hampton) Management Co. Limited | Households | 1981 |
| Longheath Community Care and Church Centre | Health & social care | 1996 |
| Longs Limited | Manufacturing | 1900 |
| Lonwell Limited | Wholesale & retail | 1971 |
| Look at This,Keith Ltd | Arts & recreation | 2014 |
| Lordden Holdings Ltd | Professional & scientific | 2002 |
| Lordden Music Ltd | Information & communication | 2002 |
| Lowes Cleaning Services Limited | Administrative & support | 2006 |
| Loxley and Tweedy Limited | Professional & scientific | 2006 |
| Loxwood Management Company Limited | Households | 1999 |
| LPM 5 Limited | Construction | 2003 |
| Lucky Windows & Doors Ltd | Manufacturing | 2002 |
| Lukes Like New Limited | Wholesale & retail | 2004 |
| Lume Beauty Limited | Other services | 2023 |
| Luresteady Limited | Information & communication | 1987 |
| Lurudan Limited | Real estate | 2005 |
| Luxmore Lighting Limited | Manufacturing | 2004 |
| Luxury Innovative Skincare Limited | Health & social care | 2024 |
| Lynborough Financial Services Limited | | 1986 |
| Lynch Maintenance Limited | Construction | 2006 |
| Lynchpin Financials Ltd | Professional & scientific | 2019 |
| Lynchpin Productions Theatre Company | Arts & recreation | 2005 |
| Lynedoch Ltd | Construction | 2016 |
| Lynmaster Limited | | 1988 |
| Lynwood Electricals Limited | Construction | 2000 |
| Lyons Clearance Services Ltd | Water & waste | 2003 |
| M & B Precision Limited | Professional & scientific | 1996 |
| M & C Builders Limited | Construction | 2006 |
| M & D Enterprises Limited | Real estate | 2005 |
| M & T Decorating Limited | Construction | 2016 |
| M & W Properties (Surrey) Limited | Households | 2005 |
| M and PW Consulting Limited | Financial services | 2003 |
| M F Air Conditioning Services Limited | Other services | 2007 |
| M for Media Limited | Professional & scientific | 1991 |
| M H Phillips Consulting Limited | Professional & scientific | 2003 |
| M Heating & Plumbing Limited | Construction | 2003 |
| M J Mansell (Groundworks) Limited | Construction | 2024 |
| M J Mcmanus Associates Limited | Transport & logistics | 2003 |
| M J R Groundworks Limited | Construction | 2005 |
| M R Dental Supplies Limited | Manufacturing | 1997 |
| M T H L Property Services Limited | Real estate | 1997 |
| M Technicians Limited | Manufacturing | 2012 |
| M V Accounting Services Limited | Professional & scientific | 2015 |
| M W F Limited | Construction | 2007 |
| M. a. Maintenance Services Limited | Construction | 2005 |
| M. B. JOB Limited | Wholesale & retail | 1977 |
| M. Batchelor Services Limited | Manufacturing | 2002 |
| M. Smith Electrical Limited | Construction | 2003 |
| M.A.C. Install Ltd | Construction | 2015 |
| M.A.G Plasterwork Specialist Ltd | Construction | 2002 |
| M.A.P. Property Services Limited | Real estate | 1987 |
| M.B.D. Investment Limited | Hospitality | 2005 |
| M.C.S. Properties Limited | | 1986 |
| M.F. Construction Services Ltd. | Professional & scientific | 1993 |
| M.J. & S.D. Little Limited | Real estate | 2002 |
| M.J. Haynes (Trainer) Limited | Arts & recreation | 1975 |
| M.J. Hook Construction Limited | Administrative & support | 2005 |
| M.J. Kloss Painting and Decorating Limited | Construction | 2002 |
| M.J.M. Electrical Services Limited | Construction | 1998 |
| M.O.K & Associates Ltd | Professional & scientific | 2005 |
| M.R.F.(U.K.) Limited | Public administration | 1976 |
| M.S. George Limited | Manufacturing | 1972 |
| M73 Homes Ltd | Real estate | 2025 |
| MA Casa Design and Construction Ltd | Construction | 2004 |
| Maal Limited | Financial services | 2017 |
| Maanu Enterprises Ltd | Wholesale & retail | 2024 |
| Maanu Properties Ltd | Construction | 2024 |
| Mabuyela Ltd | Health & social care | 2020 |
| MAC Co Holdings Limited | Financial services | 2026 |
| Macevents Limited | Arts & recreation | 1997 |
| Mackenzie Webb Associates Limited | Financial services | 2004 |
| Made in Asia Ltd | Professional & scientific | 2010 |
| Madhuban Limited | Hospitality | 2006 |
| Madoona's Ltd | Hospitality | 2017 |
| Maea UK Ltd | Wholesale & retail | 2023 |
| Maggies Cuisine Limited | Manufacturing | 2019 |
| Magic EYE Consulting Ltd | Professional & scientific | 2007 |
| Magic Town Media Limited | Professional & scientific | 2002 |
| Magimix UK Limited | Wholesale & retail | 1987 |
| Magles Productions Limited | Information & communication | 2002 |
| Magma Poetry | Arts & recreation | 2007 |
| Magna Carta Park Management Company Limited | Real estate | 2014 |
| MAH Vision Wealth Management Limited | Professional & scientific | 2014 |
| Mahaveer Impex Limited | Wholesale & retail | 1992 |
| Maheer MIR Limited | Wholesale & retail | 2026 |
| Maidmoor Limited | Real estate | 1996 |
| Mailer Shopfitters Limited | | 1968 |