| Lbca Limited | Professional & scientific | 2001 |
| Lbcts Holdings Ltd | Financial services | 2026 |
| Lbcts Operations Ltd | Professional & scientific | 2026 |
| LCC Services Ltd | Construction | 2024 |
| LCP Solutions Limited | Professional & scientific | 2011 |
| LE Fleming Aviation Services Limited | Transport & logistics | 2016 |
| LE Wine Store Limited | Wholesale & retail | 2016 |
| LEA Farm Sales Ltd | Wholesale & retail | 2012 |
| LEA Valley Taxis Ltd | Transport & logistics | 2025 |
| Lead Design Studios Ltd | Professional & scientific | 2024 |
| Leaderly Consulting Ltd | Professional & scientific | 2024 |
| Leaf Shop Ltd | Hospitality | 2010 |
| Leaf Whisperer Ltd | Administrative & support | 2022 |
| Leapfrog Digital Limited | Information & communication | 2015 |
| LED Illuminations (2009) Ltd | Construction | 2011 |
| Ledgemore Limited | Professional & scientific | 2011 |
| LEG Consultants Limited | Professional & scientific | 2019 |
| Legacy Deal Partnerships Ltd | Real estate | 2026 |
| Legal Nodes Ltd | Administrative & support | 2018 |
| Leida Limited | Extraterritorial | 2012 |
| Leida Products Ltd | Wholesale & retail | 2012 |
| Lemos Developments Ltd | Construction | 2018 |
| Lennard Associates Limited | Information & communication | 1976 |
| Lenross Limited | Real estate | 2006 |
| Lenzie Limited | Wholesale & retail | 2021 |
| Leoh Ltd | Construction | 2026 |
| Lesley Makeup and Hair Ltd | Information & communication | 2023 |
| Lethal Runners Limited | Wholesale & retail | 2025 |
| Leva Ltd | Manufacturing | 2025 |
| Leviticus Sports Management Ltd | Professional & scientific | 2021 |
| Lewis Head Personal Training Ltd | Arts & recreation | 2020 |
| Lewis Property Design & Build Ltd | Construction | 2026 |
| Lewis Property Holdings Ltd | Real estate | 2019 |
| Lewis Weir Waste Management Limited | Water & waste | 2014 |
| Lewlec Ltd | Construction | 2018 |
| Leyton Road Harpenden (Management) Company Limited | Households | 2001 |
| LHD Consulting Ltd | Professional & scientific | 2024 |
| Liberated Energy Ltd | Professional & scientific | 2024 |
| Libero Ventures Limited | Financial services | 2007 |
| Licon Cappadocia Ltd | Wholesale & retail | 2022 |
| Lifeline Properties Limited | Real estate | 2021 |
| Lifestyle Logic Limited | Construction | 2022 |
| Lift Your Feet Limited | Other services | 2017 |
| Light Beam Strategy Ltd | Professional & scientific | 2022 |
| Lilac Leadership Ltd | Administrative & support | 2017 |
| Lili OLI Limited | Professional & scientific | 2015 |
| Lilian IVY Ltd | Professional & scientific | 2021 |
| Linden Square Residents Management Company Limited | Households | 2004 |
| Link Kennels Ltd | Agriculture & fishing | 2019 |
| Linkt Ltd | Wholesale & retail | 2020 |
| Lios Holdings Limited | Real estate | 2020 |
| Little 3 Bros Limited | Information & communication | 2024 |
| Little Bones Limited | Wholesale & retail | 2020 |
| Little Brook Glamping Ltd | Hospitality | 2025 |
| Little Lost Travel Ltd | Information & communication | 2021 |
| Liveplay Golf Ltd | Information & communication | 2011 |
| Living Life Limited | Wholesale & retail | 2008 |
| LIZ Margree Limited | Professional & scientific | 2013 |
| LJ Operating Systems Ltd | Professional & scientific | 2026 |
| LJE Properties Limited | Real estate | 2018 |
| LKP Support Limited | Wholesale & retail | 2017 |
| Llyn Ltd | Wholesale & retail | 2023 |
| Lobo Residential Limited | Real estate | 2025 |
| Lobo Ventures Limited | Financial services | 2025 |
| LOC & Load Locations Limited | Arts & recreation | 2024 |
| Local Insights Limited | Other services | 2017 |
| Locker 27 Limited | Arts & recreation | 2010 |
| Locklyn Wealth Limited | Professional & scientific | 2025 |
| Locksmith Services Ltd | Administrative & support | 2009 |
| Locum CIO Services Ltd | Professional & scientific | 2022 |
| Locum VET Jenna Ltd | Professional & scientific | 2018 |
| Lomar Healthcare UK Limited | Wholesale & retail | 2023 |
| London & Essex Property Developments Limited | Real estate | 1985 |
| London Antique Jewellery Company Ltd | Extraterritorial | 2024 |
| London Facilities Ltd | Construction | 2026 |
| London JMC Building Consultants Ltd | Professional & scientific | 2021 |
| London Self Storage Group Ltd | Real estate | 2019 |
| Londonvest Ltd | Real estate | 2020 |
| Longstanton Flat Management Company Limited | Households | 1983 |
| Lothius Ltd | Information & communication | 2025 |
| Lotus-Property-Consultancy Ltd | Real estate | 2017 |
| Loved Digital UK Ltd | Information & communication | 2026 |
| Loveweds Jewellers Limited | Administrative & support | 2011 |
| Lower Luton Road Flats Management Company Limited | Administrative & support | 1975 |
| Lower Spending Solutions Limited | Administrative & support | 2006 |
| LP3 Consulting Limited | Professional & scientific | 2023 |
| LUC Edwards Productions Limited | Manufacturing | 2020 |
| Lucky BEE Media Ltd | Wholesale & retail | 2020 |
| Ludgate Clinic Ltd | Health & social care | 2014 |
| Lumin Nuclear Medicine Ltd | Professional & scientific | 2026 |
| Lumos Dental Centre Ltd | Health & social care | 2023 |
| Luna ARC Ltd | Wholesale & retail | 2024 |
| Lure Geek Limited | Agriculture & fishing | 2015 |
| Luvaura Limited | Wholesale & retail | 2025 |
| LUX Tanning Aesthetics Ltd | Other services | 2024 |
| Luxe and Key Ltd | Real estate | 2022 |
| Luxr London Limited | Wholesale & retail | 2025 |
| LW2019 Limited | Professional & scientific | 2019 |
| Lydekker Mews Residents Association Limited | Households | 1985 |
| Lyndhurst Asset Management Limited | Professional & scientific | 2000 |