| LKE Management Services Ltd | Construction | 2016 |
| LL Joydens Wood Ltd | Other services | 2025 |
| LMA Lettings Ltd | Real estate | 2025 |
| LMK Kent Limited | Construction | 2018 |
| LMQ Properties Limited | Real estate | 2001 |
| LNK8 Limited | Administrative & support | 2025 |
| Loar Construction Ltd | Construction | 2023 |
| Loba DNC Limited | Construction | 2022 |
| Lodgi Ltd | Real estate | 2024 |
| Lodhi Consulting Limited | Manufacturing | 2016 |
| Lolakins Limited | Professional & scientific | 2022 |
| London and South East Surveys Limited | Professional & scientific | 2022 |
| London City Demolition Ltd | Construction | 2025 |
| London Dockland Ltd | Construction | 2022 |
| London Elite Colorectal Clinic Ltd | Health & social care | 2026 |
| London Engineering Group Ltd | Wholesale & retail | 2026 |
| London GRP Roofing Ltd | Construction | 2019 |
| Londonprivatemedical Ltd | Health & social care | 2023 |
| Londons Best Ltd | Administrative & support | 2023 |
| Long Buckby Holdings Ltd | Financial services | 2020 |
| Longview Care Home Limited | Wholesale & retail | 2016 |
| Lookartme Ltd | Wholesale & retail | 2025 |
| Lore Limited | Administrative & support | 2002 |
| Lorima Ventures Limited | Information & communication | 2010 |
| Lorraine Logistics Ltd | Transport & logistics | 2020 |
| Loshi Limited | Administrative & support | 2017 |
| Lost Lily Tattoo Ltd | Arts & recreation | 2025 |
| Lothbury Consulting Ltd | Information & communication | 2010 |
| Lotus Human Resource Consultancy Limited | Administrative & support | 1997 |
| Loubear Productions Ltd | Administrative & support | 2025 |
| Louise Lambell Limited | Other services | 2014 |
| Love (UK) Limited | Real estate | 2012 |
| Love Empire Ltd | Wholesale & retail | 2018 |
| Love Language Learning Ltd | Education | 2012 |
| Lovely Productions Limited | Administrative & support | 2008 |
| Lovesome Beauty Ltd | Other services | 2023 |
| LR Electrical and Contracts Ltd | Construction | 2025 |
| LR Pet Health Ltd | Professional & scientific | 2024 |
| LS London Electrical Ltd | Construction | 2026 |
| LS Waste Management Ltd | Water & waste | 2026 |
| Lucksoon Investments & Ventures Limited | Wholesale & retail | 2000 |
| Lucky Ricky & Co.Limited | Real estate | 1985 |
| Lucy Limited | Professional & scientific | 2001 |
| Lushi Projects Ltd | Professional & scientific | 2021 |
| Luship Ltd | Professional & scientific | 2025 |
| Lushnja Stone Ltd | Construction | 2021 |
| LUV2BS Ltd | Professional & scientific | 2023 |
| Luxo Gallery Ltd | Professional & scientific | 2025 |
| Luxury Evolution Limited | Wholesale & retail | 2018 |
| Luxury First Ltd | Real estate | 2020 |
| LWP Builders Limited | Construction | 2003 |
| Lycian Luxury Collection Ltd | Hospitality | 2015 |
| Lyndhurst Nursing Home Ltd. | Health & social care | 2002 |
| Lynn Care Ltd | Health & social care | 2012 |
| M & a Installations Limited | Construction | 2006 |
| M & S Home Installations Limited | Construction | 2013 |
| M Building Solutions Ltd | Construction | 2015 |
| M J Saunders Ltd | Construction | 2016 |
| M&M Prestige Ltd | Other services | 2024 |
| Mabara Labs Limited | Professional & scientific | 2025 |
| Maco Distribution Limited | Financial services | 2023 |
| Made in Kent Limited | Information & communication | 2021 |
| Madeira Consultancy LLP | | 2017 |
| Madison Mortgages Limited | Financial services | 2017 |
| Madstein Systems Limited | Administrative & support | 2002 |
| Magic Colour Picture Box Ltd | Information & communication | 2012 |
| Magic IS Real Ltd | Health & social care | 2024 |
| Magra Consulting Limited | Professional & scientific | 2023 |
| Magyk Television Limited | Information & communication | 2015 |
| MAH Design Ltd | Construction | 2022 |
| MAI Building Services Limited | Construction | 2015 |
| MAI Group Limited | Financial services | 2015 |
| Maida Vale Property Investment Ltd | Real estate | 2025 |
| Maidenbridge Properties Limited | Real estate | 2005 |
| Mains Distro Ltd | Manufacturing | 2018 |
| Maintenance 4 U Ltd | Other services | 2017 |
| Maison Mere Ltd | Real estate | 2025 |
| Malekos Investments Ltd | Real estate | 2017 |
| Malola Limited | Information & communication | 2015 |
| Maltrak Limited | Financial services | 2024 |
| Malz Care Services Limited | Health & social care | 2024 |
| Malz Properties Ltd | Real estate | 2023 |
| Mandy’S Group Limited | Transport & logistics | 2020 |
| Mane London Limited | Wholesale & retail | 2025 |
| Manku Developments Ltd | Construction | 2025 |
| Mann Homes Group Ltd | Construction | 2024 |
| Mann Homes Ltd | Real estate | 2015 |
| Manning-Coote Limited | Other services | 2023 |
| Manokamana Ltd | Health & social care | 2011 |
| Manor Homeware Limited | Wholesale & retail | 2025 |
| Mantell Contractors Limited | Manufacturing | 2014 |
| Maple Building & Maintenance Limited | Real estate | 2005 |
| Maplehurst Residence Company Limited | Households | 1973 |
| Maples Electrical Engineering Ltd | Construction | 2025 |
| Marco Oliveri Ltd | Wholesale & retail | 2021 |
| Marjean Limited | Real estate | 2021 |
| Mark IAN Harrop Consulting Limited | Professional & scientific | 2025 |
| Markalation Ltd | Information & communication | 2026 |
| Marlings Group Holdings Ltd | Financial services | 2026 |
| Marmoura Limited | Real estate | 2023 |