| Lari & ARI Ltd | Construction | 2020 |
| Larry's Drycleaners Ltd | Other services | 2020 |
| Lasar Investments Ltd | Real estate | 2024 |
| Lasberk Limited | Health & social care | 2018 |
| Laser Clinic Expert Limited | Other services | 2024 |
| Laser Expert Ltd | Other services | 2014 |
| Laser Furniture Ltd | Administrative & support | 2006 |
| Laserpoint UK Limited | Manufacturing | 2023 |
| Lash Girl London Ltd | Other services | 2018 |
| Laskobuild Limited | Professional & scientific | 2016 |
| Last Minute Drycleaning Ltd | Other services | 2025 |
| Latchcraft Limited | Real estate | 2015 |
| Latrixa Limited | Professional & scientific | 2026 |
| Laura Hair and Beauty Enfield Ltd | Other services | 2019 |
| Laurence Whitefield Ltd | Health & social care | 2010 |
| Laurentiu Manolache Ltd | Other services | 2014 |
| Laurentiu Service Ltd | Construction | 2018 |
| Lavech Ltd | Real estate | 2024 |
| Lavender House (Elms Road) Management Limited | Households | 2013 |
| Lawley Structural Design Limited | Professional & scientific | 2025 |
| Laya House Ltd | Real estate | 2018 |
| Lazari Fine Jewellers Limited | Manufacturing | 2016 |
| Lazuli Group Limited | Wholesale & retail | 2025 |
| Lazybones UK Limited | Real estate | 2005 |
| LBB Consultancy Ltd | Professional & scientific | 2021 |
| LBW Commodities Ltd | Wholesale & retail | 2015 |
| LC Pro Performance Ltd | Arts & recreation | 2024 |
| LC Treecare Ltd | Administrative & support | 2023 |
| LCD Construction Limited | Construction | 2025 |
| LCG Railway Limited | Construction | 2017 |
| LDJ Solution Ltd | Construction | 2015 |
| LE Legal Ltd | Professional & scientific | 2025 |
| Lead Tutoring Limited | Education | 2020 |
| Leafaura UK Limited | Wholesale & retail | 2025 |
| Leamington House RTM Company Limited | Real estate | 2005 |
| Leap Educational Consultancy Limited | Education | 2015 |
| Learn Nation Limited | Education | 2017 |
| Learning Corner Nursery Ltd | Education | 2015 |
| Learning Encounters Limited | Professional & scientific | 2004 |
| Lecr Property Holding Limited | Real estate | 2022 |
| Ledgerfy Accounting Ltd | Professional & scientific | 2025 |
| Ledgers to Balance LLP | | 2023 |
| Ledjon Decorating Ltd | Construction | 2022 |
| LEE Avenue Limited | Wholesale & retail | 2021 |
| LEE Harvey Limited | Information & communication | 2010 |
| LEE W Holroyd Limited | Professional & scientific | 2024 |
| Leecious UK Ltd | Wholesale & retail | 2019 |
| Lees News Limited | Wholesale & retail | 2012 |
| Leg-Nexus Consultancy Limited | Administrative & support | 2014 |
| Legacy 78 Limited | Wholesale & retail | 2022 |
| Legal Futures Publishing Limited | Information & communication | 2010 |
| Legge Carpets Limited | Wholesale & retail | 2011 |
| Legit Software Ltd | Information & communication | 2022 |
| Leila Housing Limited | Real estate | 2023 |
| Leit Werk Limited | Professional & scientific | 2001 |
| Lekki PHASE2 Ltd | Hospitality | 2023 |
| Lele Estates Limited | Construction | 2024 |
| Lemon Lunar Ltd | Wholesale & retail | 2015 |
| Lemsford Estate Management Limited | Real estate | 1973 |
| Lena Supermarket Ltd | Wholesale & retail | 2024 |
| LEO Academy Limited | Education | 2021 |
| LEO Asset Group Ltd | Real estate | 2025 |
| LEO Education Limited | Education | 2019 |
| LEO MP Limited | Construction | 2016 |
| LEO POP Construction Property Maintenance Ltd | Construction | 2025 |
| Leocross Limited | Health & social care | 2010 |
| Leon Kennedy Ltd | Hospitality | 1998 |
| Leon's Lots Limited | Real estate | 2025 |
| Leor Video Productions Ltd | Information & communication | 2014 |
| Leora Ltd | Health & social care | 2023 |
| Leoted Care Limited | Health & social care | 2026 |
| Lepania Build Ltd | Construction | 2026 |
| LER Design Limited | Professional & scientific | 2026 |
| LES Papillons Limited | Health & social care | 2022 |
| LES Petits Parfums Limited | Wholesale & retail | 2009 |
| Leslie Morris Mortgage Services Limited | Financial services | 2021 |
| Lestair Services Limited | Professional & scientific | 2017 |
| LET Property Matters Limited | Real estate | 2021 |
| LET Your Beauty Shine Limited | Other services | 2015 |
| Let's Property Ltd | Real estate | 2016 |
| Letterbox Liquorice Limited | Wholesale & retail | 2020 |
| Letterbox Sweets Limited | Hospitality | 2020 |
| Lettings Battersea Ltd | Hospitality | 2022 |
| Level PAR Bloodstock Limited | Agriculture & fishing | 2012 |
| Level UP Psychology Limited | Professional & scientific | 2025 |
| Lewbridge Associates Limited | Hospitality | 2016 |
| Lewis & Christian Limited | Transport & logistics | 2017 |
| Lewis Leathers Limited | Manufacturing | 2003 |
| Lewisham Express Mobile Ltd | Wholesale & retail | 2025 |
| Leyten Chicken Limited | Hospitality | 2023 |
| LF Consulting and Advisory Ltd | Professional & scientific | 2024 |
| LF Letting Ltd | Real estate | 2024 |
| LF Management Operations Ltd | Real estate | 2024 |
| LF Music Limited | Arts & recreation | 2011 |
| LF Sales Services Ltd | Real estate | 2024 |
| Lfdtrans Ltd | Construction | 2025 |
| LGT Express Solutions Ltd | Other services | 2018 |
| Lian Kitchen Services Limited | Manufacturing | 2024 |
| Libra Accountancy and Tax Services Limited | Professional & scientific | 2020 |
| Licomo 29 Ltd | Transport & logistics | 2026 |