| Leitrim Properties Holdings Limited | Financial services | 2018 |
| Leitrim Properties Limited | Real estate | 1997 |
| Lema Online Limited | Information & communication | 2019 |
| Lemontree Investments Ltd | Real estate | 2023 |
| Lemsford Smallholding Ltd | Agriculture & fishing | 2023 |
| Lenjordan Ltd | Information & communication | 2025 |
| Lenzi Optical Limited | Wholesale & retail | 2025 |
| LEO Global Investments Ltd | Real estate | 2017 |
| Leoleo Ltd | Real estate | 2020 |
| Leonard Irvin Property Corporation Limited | Real estate | 1993 |
| Leontine West Ltd | Professional & scientific | 2013 |
| Leopard 1 Limited | Real estate | 2015 |
| Leporce Logistics Ltd | Transport & logistics | 2024 |
| Less Properties Limited | Real estate | 2013 |
| Lessash Consultancy Limited | Administrative & support | 2016 |
| Let's Aliyah Ltd | Real estate | 2024 |
| Let's Grow Young Ltd | Other services | 2024 |
| Lets R US Limited | Households | 2021 |
| Leveson Hire Limited | Administrative & support | 2010 |
| Levin Wines Limited | Wholesale & retail | 1990 |
| Levisga Ltd | Information & communication | 2018 |
| Lexington Five Consultancy Limited | Administrative & support | 2017 |
| LGM Construction Limited | Construction | 2018 |
| LH Pre-School Limited | Education | 2017 |
| LH SPV Limited | Financial services | 2024 |
| Libas Systems Limited | Information & communication | 2000 |
| Liberi Consulting Ltd | Professional & scientific | 2020 |
| Lichfield Grove Limited | Real estate | 2004 |
| Liddle IT Limited | Information & communication | 2014 |
| Lidington & Company Ltd | Professional & scientific | 2022 |
| Life With Sabin Ltd | Other services | 2023 |
| Lifespark Technologies UK Limited | Manufacturing | 2023 |
| Lightlook Limited | Real estate | 1998 |
| Lightmight Holdings Limited | Real estate | 2020 |
| Lightmight Limited | Real estate | 2020 |
| Like Love Want Limited | Arts & recreation | 2012 |
| Lima Hotel Limited | Hospitality | 2026 |
| Limla Limited | Other services | 1990 |
| Linckps Limited | Information & communication | 2025 |
| Lincrest Limited | Professional & scientific | 1947 |
| Lindsay Park Nursery School Limited | Health & social care | 2012 |
| Lines (Local & International Network Exchange Services) Limited | Information & communication | 2000 |
| Lines London Ltd | Hospitality | 2019 |
| Link to Experts Ltd | Administrative & support | 2015 |
| Linkca Ltd | Extraterritorial | 2010 |
| Linkdeal Limited | Wholesale & retail | 1991 |
| Linksway Investments Ltd. | Financial services | 2021 |
| Linton Village Pharmacy Limited | Wholesale & retail | 2021 |
| Lioness Advisory Ltd | Professional & scientific | 2014 |
| Lionscorp Limited | Construction | 2009 |
| Lipman Legacy Limited | Real estate | 2023 |
| Lishk Limited | Health & social care | 2013 |
| Litex (UK) Limited | Wholesale & retail | 1992 |
| Litex Group Limited | Professional & scientific | 2003 |
| Little & Lampert Pianos Ltd | Wholesale & retail | 2013 |
| Little Birdy Investments Ltd | Real estate | 2020 |
| Little Court Residents Association Limited | Real estate | 1969 |
| Little Healing Ltd | Arts & recreation | 2023 |
| Littleborough Practice Ltd | Health & social care | 2014 |
| Liv's International Ltd | Transport & logistics | 2022 |
| Livadas Consulting Ltd | Professional & scientific | 2022 |
| Lixu Digital Ltd | Information & communication | 2023 |
| Liyana & Ayaan Ltd | Financial services | 2015 |
| Liza Trading Ltd | Wholesale & retail | 2020 |
| LJ United Capital Ltd | Real estate | 2025 |
| LJS Designs & Projects Ltd | Manufacturing | 2025 |
| LKR Associates Limited | Construction | 2025 |
| LKY Cars Ltd | Wholesale & retail | 2020 |
| LMT Design Ltd | Construction | 2019 |
| Local Residential Properties Limited | Real estate | 1998 |
| Local Shopper Limited | Wholesale & retail | 2000 |
| Lochmalony Renewables Limited | Energy | 2014 |
| Lock Stock & Barrel (Brighton) Ltd | Other services | 2014 |
| Lodore Properties LLP | | 2025 |
| Logarithm Services Limited | Professional & scientific | 2018 |
| Logical Property Trading Ltd | Real estate | 2014 |
| Logical Resilience Limited | Professional & scientific | 2018 |
| Logistics London Limited | Transport & logistics | 2002 |
| Logistics Recruitment UK Limited | Administrative & support | 2022 |
| Loltean Quality Services Ltd | Information & communication | 2024 |
| Lomax Ventures Limited | Hospitality | 2018 |
| Londinium Real Estate Ltd | Real estate | 2020 |
| London Apartment Direct Limited | Real estate | 2010 |
| London Brew Productions Limited | Arts & recreation | 2020 |
| London Bubble Limited | Wholesale & retail | 2021 |
| London Building Renovation Limited | Construction | 2007 |
| London Cable & Lighting Limited | Wholesale & retail | 2004 |
| London Child Psychology Practice Limited | Health & social care | 2013 |
| London College of Science & Technology Ltd | Education | 2016 |
| London Fitness and Strength Limited | Education | 2025 |
| London French Rugby Football Club Limited | Arts & recreation | 2013 |
| London Geocaching Limited | Administrative & support | 2025 |
| London Gifts (PVT) Ltd | Wholesale & retail | 2020 |
| London Global Media Limited | Information & communication | 2008 |
| London Gynae Health Ltd | Health & social care | 2024 |
| London Hand Surgery Ltd | Health & social care | 2010 |
| London Hearing Specialist Ltd | Extraterritorial | 2018 |
| London Herts and Essex Recovery Ltd | Transport & logistics | 2024 |
| London Line Homes Ltd. | Construction | 2018 |
| London Matrix Ltd | Administrative & support | 2012 |