| Leiton Future Research Center Limited | Manufacturing | 2019 |
| Lejit Football Development Ltd | Education | 2024 |
| Lelance Dairy Ltd | Agriculture & fishing | 2026 |
| Lenda Consulting Ltd | Financial services | 2025 |
| Lenga Limited | Extraterritorial | 2002 |
| LEO & Co Consulting Limited | Other services | 2009 |
| Leone Paye Limited | Real estate | 2017 |
| Leopard Technology Ltd | Manufacturing | 2019 |
| Lepanto Limited | Professional & scientific | 2025 |
| LES Quis.Com Limited | Administrative & support | 2012 |
| Leslie Court Management Co. Limited | Households | 1987 |
| Let's Communicate Ltd | Health & social care | 2022 |
| Letchford’S Ltd | Construction | 2022 |
| Letsgoweb Solutions Limited | Information & communication | 2018 |
| Levico Trans Ltd | Transport & logistics | 2018 |
| Levmarc Ltd | Financial services | 2026 |
| Lewis Security Consultancy Ltd | Administrative & support | 2014 |
| Lewisham Organ Centre Limited (the) | Professional & scientific | 1973 |
| Lewkas Ltd | Professional & scientific | 2024 |
| Lexa Building Services Limited | Construction | 2012 |
| Lexa MX Ltd | Wholesale & retail | 2022 |
| Lexa Waste Management Limited | Water & waste | 2025 |
| Lexa's Interiors Limited | Wholesale & retail | 2018 |
| LGT Serban Ltd | Transport & logistics | 2024 |
| Liberty & Monroe Limited | Administrative & support | 2024 |
| Life IS AI Limited | Other services | 2018 |
| Lifeconstruct Ltd | Construction | 2026 |
| Lifeiz Ltd | Hospitality | 2025 |
| Lifeline Cars Limited | Wholesale & retail | 2020 |
| Lifeset Ltd | Education | 2026 |
| Lifetime Assets Group Ltd | Real estate | 2019 |
| Lift Each Other Ltd | Arts & recreation | 2020 |
| Lift Smart Ltd | Manufacturing | 2021 |
| Lifting London Limited | Professional & scientific | 2024 |
| Liftup Lifts Limited | Construction | 2018 |
| Liftwell Southern Ltd | Manufacturing | 2014 |
| Light and Sound Limited | Administrative & support | 2005 |
| Lightbulb ES Limited | Professional & scientific | 2016 |
| Lighten Healthcare Ltd | Health & social care | 2025 |
| Lighthouse Real Estate 1 General Partner Limited | Financial services | 2022 |
| Like Consulting Ltd | Professional & scientific | 2014 |
| Like Glass Aesthetics Ltd | Other services | 2025 |
| Like Home (West Wickham) Limited | Hospitality | 2024 |
| Likes Glow Ltd | Health & social care | 2025 |
| Lilly Brook Childcare Ltd | Education | 2015 |
| Lillyvern's Limited | Manufacturing | 2016 |
| Lime Tree Place (Common Parts) Management Limited | Households | 2014 |
| Linay & Shipp Financial LLP | | 2023 |
| Linay & Shipp Limited | Real estate | 2005 |
| Linda Schimmel Consulting Ltd | Information & communication | 2022 |
| Linda Super Nanny Ltd | Health & social care | 2020 |
| Linden Court (Wickham Road) Residents Company Limited | Households | 1984 |
| LINDOS2025 Ltd | Real estate | 2025 |
| Link Education Limited | Administrative & support | 2000 |
| Links Accounting Services Ltd | Professional & scientific | 2007 |
| Linksap Europe Limited | Information & communication | 2015 |
| Linton Recruitment Solutions Ltd | Administrative & support | 2014 |
| Linux Server Enterprise BCP Ltd | Information & communication | 2013 |
| Lion Consultants Limited | Information & communication | 2014 |
| Lionandblade Ltd | Other services | 2026 |
| Lione & Sons Ltd | Financial services | 2025 |
| Lions Loft Ltd | Real estate | 2019 |
| Liquidity Club Limited | Financial services | 2017 |
| LIS Sweet Homes Ltd | Real estate | 2019 |
| Lisa UME Therapy Limited | Health & social care | 2026 |
| Lisnic Company Ltd | Construction | 2019 |
| Listed Building Restoration Ltd | Construction | 2011 |
| Liteful Limited | Wholesale & retail | 2016 |
| Litsu Ltd | Health & social care | 2016 |
| Little Big Treats Ltd | Hospitality | 2023 |
| Little Black Door Ltd | Administrative & support | 2025 |
| Little Crocs Limited | Health & social care | 2023 |
| Little Dayane Ltd | Wholesale & retail | 2022 |
| Little Smiles Nursery Limited | Health & social care | 2025 |
| Little Venhay Limited | Real estate | 2022 |
| LIV2DESIGN Ltd | Construction | 2015 |
| Liverbird Holdings Ltd | Financial services | 2021 |
| Liveridge Asset Management Limited | Administrative & support | 2021 |
| Liveridge Consultants Limited | Professional & scientific | 2017 |
| Living Holidays Limited | Administrative & support | 2008 |
| Liviu & SON Limited | Construction | 2013 |
| LKM Property Services Ltd | Real estate | 2026 |
| LKZ Services Ltd | Manufacturing | 2019 |
| LM Sprinklers Limited | Construction | 2024 |
| LM West Consulting Ltd | Professional & scientific | 2017 |
| LM West Property Limited | Real estate | 2016 |
| LMC Racquets Club Ltd | Administrative & support | 2024 |
| Lmcw Servies Ltd | Professional & scientific | 2024 |
| LN Residential Ltd | Real estate | 2026 |
| LNJ Consultancy Limited | Professional & scientific | 2017 |
| Loarna AI Ltd | Information & communication | 2024 |
| Lobo's BBQ Ltd | Hospitality | 2023 |
| LOC UK Ltd | Manufacturing | 2008 |
| Local Plumbers Direct Ltd | Construction | 2023 |
| Locks Edge Wealth Management Ltd | Professional & scientific | 2026 |
| Locksbottom Town Football Club Limited | Arts & recreation | 2024 |
| Locums MA Limited | Health & social care | 2016 |
| Loem Enterprises Limited | Wholesale & retail | 2019 |
| Logs Hill Holdings Limited | Real estate | 2016 |
| Lombard Rand Limited | Financial services | 1989 |