| Leggati Limited | Wholesale & retail | 2020 |
| Leicester GT Education Company Limited | Construction | 2007 |
| Leigham Lodge Limited | Health & social care | 2002 |
| Leighton Copying Systems Limited | | 1986 |
| Leiria Ltd | Administrative & support | 2016 |
| Leka-Befidi Ltd | Administrative & support | 2018 |
| Lekker Investments Ltd | Real estate | 2019 |
| Lemon Brick Properties Limited | Real estate | 2017 |
| Lenor Enterprises Ltd | Real estate | 2024 |
| LEO and Wild Limited | Arts & recreation | 2025 |
| LEO Building Construction Limited | Construction | 2007 |
| Leogrand Services Ltd | Construction | 2016 |
| Leomae Limited | Administrative & support | 2012 |
| Leon Express Ltd | Transport & logistics | 2015 |
| Leonard Albert Consultancy Services Ltd | Professional & scientific | 2011 |
| Leonard Steel Works Limited | Construction | 2020 |
| Leroy DA Costa Private Holdings UK Limited | Financial services | 2025 |
| Lestar Developments Ltd | Construction | 2010 |
| LET in Luxury Limited | Real estate | 2021 |
| Let's Talk Counselling Limited | Health & social care | 2013 |
| Leto Global Ltd | Real estate | 2025 |
| Lettuce Marketing Ltd | Professional & scientific | 2022 |
| Leuca Transport Limited | Transport & logistics | 2022 |
| Level 5 Lifestyle Distributors Ltd | Manufacturing | 2019 |
| Levél CLO Limited | Wholesale & retail | 2025 |
| Lewedin Group Limited | Mining & quarrying | 2024 |
| Lewi & Siem Ltd | Health & social care | 2018 |
| LEX Magni Limited | Professional & scientific | 2017 |
| Lexham Securities Limited | Real estate | 1988 |
| Lexicon Emea Ltd | Administrative & support | 2013 |
| Lexmark International Ltd | Manufacturing | 1990 |
| Lexon Investment Ltd | Real estate | 2023 |
| Leyton Hughes Limited | Manufacturing | 2025 |
| LFS Health Ltd | Wholesale & retail | 2021 |
| LG Woods Building Services Ltd | Construction | 2026 |
| LGG Therapeutics Limited | Professional & scientific | 2020 |
| LGV Trans Logistics Ltd | Transport & logistics | 2023 |
| LHC Procurement Group Limited | Administrative & support | 2023 |
| LHR Airport Transfer Ltd | Transport & logistics | 2022 |
| LHR Global Logistics Ltd | Administrative & support | 2010 |
| LHR Transfers Ltd | Transport & logistics | 2024 |
| LI Fashion Trading Limited | Wholesale & retail | 2026 |
| Liberation Ventures Limited | Professional & scientific | 1997 |
| Liberty Living Solutions CIC | Health & social care | 2025 |
| Libon Construction Ltd | Construction | 2015 |
| LIC Global Limited | Administrative & support | 2024 |
| Life & Wellness Ltd | Public administration | 2025 |
| Life Care Plus Limited | Health & social care | 2016 |
| Lifeaze Ltd | Wholesale & retail | 2024 |
| Lifestyle IT Limited | Information & communication | 2001 |
| Lifinity Group Limited | Wholesale & retail | 2025 |
| Light in Shadows Ltd | Construction | 2021 |
| Lightbox (Bracknell) Limited | Real estate | 2021 |
| Lightbox (Reading) Limited | Real estate | 2022 |
| Lightbox Property Holdings Limited | Financial services | 2021 |
| Lightcam Rentals Ltd | Administrative & support | 2023 |
| Lightheaded Limited | Other services | 2014 |
| Lighthouse TD Ltd | Construction | 2022 |
| Lightplanet Limited | Wholesale & retail | 2019 |
| Lightwater Property Services Ltd | Construction | 2019 |
| Lik&Son Ltd | Professional & scientific | 2024 |
| Like a Beautiful Day Ltd | Hospitality | 2022 |
| Lillie Square Nominee Limited | Extraterritorial | 2011 |
| Lily Wolfe Tattoo Limited | Other services | 2026 |
| Lime Green BOW Limited | Extraterritorial | 2005 |
| Limetree Corner Limited | Real estate | 1993 |
| Linchfield Property Management LLP | | 2010 |
| Linda Brunker Ltd | Arts & recreation | 2026 |
| Lindiswara Court Residents Association (Croxley Green) Limited | Real estate | 1963 |
| Lindsay Court Management (High Wycombe) Limited | Households | 2011 |
| Lines & Signs Limited | Administrative & support | 2003 |
| Linford Christie Academy Limited | Arts & recreation | 2021 |
| Linguist Services Limited | Professional & scientific | 2018 |
| Linja Properties Ltd | Real estate | 2019 |
| Link UP Estate Agency Ltd | Real estate | 2013 |
| LINK2LONDON Ltd | Water & waste | 2014 |
| Linklers Limited | Education | 2014 |
| Linktech Recruitment Limited | Administrative & support | 2008 |
| Lintott Control Systems Limited | Manufacturing | 2005 |
| Lintott Environmental Technologies Limited | Financial services | 2016 |
| Lion Rock Studios Ltd | Wholesale & retail | 2022 |
| Lion Tax Services Limited | Professional & scientific | 2005 |
| Lioncrest Properties Ltd | Construction | 2022 |
| Lionize Ltd | Manufacturing | 2019 |
| Lionsgate Construction Ltd | Construction | 2012 |
| Lirica Cruise Limited | Transport & logistics | 2025 |
| Lisa Burke Limited | Professional & scientific | 2007 |
| Lissome Ltd | Information & communication | 2021 |
| Litch Care Services Limited | Health & social care | 2015 |
| Lite Technology Ltd. | Professional & scientific | 2009 |
| Little Acres Stables Ltd | Agriculture & fishing | 2024 |
| Little Bird Ltd | Agriculture & fishing | 2021 |
| Little Miss Delhi Kiosks Ltd | Hospitality | 2025 |
| Littlebig Books Ltd | Information & communication | 2011 |
| Littleoats Ltd | Real estate | 2021 |
| Littletutorhouse Limited | Education | 2020 |
| Live & Lounge Ltd | Real estate | 2025 |
| Live Wisdom Ltd | Information & communication | 2025 |
| Livia Solutions Limited | Information & communication | 2013 |
| Living and Flow Ltd | Other services | 2021 |