| Leinster Mews Management Company Limited | Real estate | 2005 |
| Leisure Activity Holdings Ltd | Transport & logistics | 2020 |
| Leisure and Conference UK Limited | Administrative & support | 2019 |
| Lemas Property Co.Limited | Real estate | 1963 |
| Lemon and Lime Marketing Limited | Professional & scientific | 2023 |
| Lemon Media Limited | Arts & recreation | 2019 |
| Lemon Tree Greek Food Ltd | Hospitality | 2023 |
| Lenihan Property Investments UK Ltd | Construction | 2022 |
| Lenita Limited | Financial services | 2012 |
| Lentworth IT Limited | Administrative & support | 2021 |
| Lenvi Productions Limited | Administrative & support | 2018 |
| Leo.B.Seligmann and Company Limited | Professional & scientific | 1932 |
| Leon Films Ltd | Information & communication | 2013 |
| Leonida Property Partnership LLP | | 2024 |
| Leopold Cameras Limited | Manufacturing | 1960 |
| Leopold Professional Services Limited | Manufacturing | 1968 |
| LESSTAX2PAY (Barnet) Ltd | Professional & scientific | 2013 |
| LESSTAX2PAY (Registrars) Limited | Other services | 2007 |
| LESSTAX2PAY (WGC) Limited | Professional & scientific | 2016 |
| LESSTAX2PAY Accountants Ltd | Professional & scientific | 2021 |
| LESSTAX2PAY Limited | Administrative & support | 2013 |
| LESSTAX2PAY Media Services Limited | Administrative & support | 2011 |
| LET Go Retreats Ltd | Administrative & support | 2016 |
| LET ME in Ltd | Hospitality | 2024 |
| LET ME Write Ltd | Professional & scientific | 2024 |
| Letchmore Ltd | Real estate | 2023 |
| Lets BID Property Ltd | Other services | 2017 |
| Letterbox Distribution Limited | Professional & scientific | 2024 |
| LEU Ltd | Wholesale & retail | 2018 |
| Level Consulting Limited | Professional & scientific | 2022 |
| Levelupszn Ltd | Information & communication | 2025 |
| Levi Gardens Limited | Administrative & support | 2026 |
| Levicta Wines Limited | Administrative & support | 2014 |
| Levina Accommodations Ltd | Hospitality | 2024 |
| Levisons Limited | Wholesale & retail | 2010 |
| Levla Limited | Real estate | 2003 |
| Lewis & Winter Properties Limited | Administrative & support | 2011 |
| Lewis Jenkins Consulting Limited | Administrative & support | 2018 |
| Lewismotorgroup Ltd | Wholesale & retail | 2022 |
| Lexamrio 2 Limited | Construction | 2002 |
| Lexanest Ltd | Wholesale & retail | 2025 |
| Lexi Sphere UK Limited | Professional & scientific | 2024 |
| Leygreen Limited | Households | 1979 |
| LFI Logistics Limited | Wholesale & retail | 2013 |
| LFS Limited | Wholesale & retail | 1962 |
| Lgec Capital Partners LLP | | 2017 |
| Lgspv Ltd | Real estate | 2022 |
| LH and Sons Building Services Ltd | Construction | 2025 |
| LH Studio Limited | Other services | 2019 |
| LIA Concepts Ltd | Hospitality | 2023 |
| Liaoning Light Industrial Products IMP. & EXP. Corp. | | 1994 |
| Liberation Build Limited | Professional & scientific | 2014 |
| Libero Capital Ltd | Real estate | 2014 |
| Libra Investment Group Ltd | Financial services | 2017 |
| Librani Care Services Limited | Health & social care | 2022 |
| Lief Essentials Limited | Wholesale & retail | 2016 |
| Liemac Ltd | Financial services | 2023 |
| Lieve Ltd | Wholesale & retail | 2026 |
| Life Line Clothing Limited | Wholesale & retail | 2020 |
| Light Business Support Services Limited | Extraterritorial | 2023 |
| Light Oak Limited | Real estate | 2022 |
| Lighted Life Counselling & Coaching Limited | Professional & scientific | 2022 |
| Lightning International (China) Limited | Information & communication | 2016 |
| Lila Restaurants Ltd | Hospitality | 2020 |
| Lilac Marshmallow Limited | Health & social care | 2007 |
| Lili & Cece Ltd | Education | 2025 |
| Lili Jewels Ltd | Manufacturing | 2017 |
| Lili Productions Limited | Other services | 2011 |
| Lillygreen Ltd | Hospitality | 2012 |
| Lily Lodge Support Services Ltd | Information & communication | 2020 |
| Lilywood Carpentry Limited | Manufacturing | 2013 |
| LIM Investment Holdings Ltd | Construction | 2021 |
| Limaai Ltd | Wholesale & retail | 2025 |
| Lime's Cafe N21 Limited | Hospitality | 2020 |
| Limecello Limited | Financial services | 2020 |
| Limecello Properties Ltd | Real estate | 2021 |
| Limelight Global Limited | Professional & scientific | 2022 |
| Limelight Publicity Limited | Real estate | 2004 |
| Limen Property Limited | Real estate | 2020 |
| Limes Cafe Hadley Wood Ltd | Hospitality | 2023 |
| Limesound Limited | Other services | 1993 |
| Limetree Court Management Limited | Real estate | 1999 |
| Limitless Logistics Ltd | Transport & logistics | 2019 |
| Limitless Training Co Limited | Other services | 2024 |
| Lincoln and Boston Limited | Transport & logistics | 2016 |
| Lincoln Road Blocks a, B, C, D Management Company Limited | Households | 1991 |
| Lincoln Road Blocks E, F, G Management Company Limited | Households | 1991 |
| Lincoln Road Blocks H, J, K Management Company Limited | Households | 1991 |
| Lincolnshire Trading and Management Limited | Transport & logistics | 2019 |
| Linderoth Kingsly (Edmonton) Limited | Real estate | 2011 |
| Lindrew Limited | Real estate | 2018 |
| Lindsey-Harrison Consulting Ltd | Education | 2026 |
| Lingam Builders Merchant Limited | Wholesale & retail | 2020 |
| Lini Construction Ltd | Construction | 2025 |
| Link News Ltd | Wholesale & retail | 2019 |
| Linkom Ltd | Wholesale & retail | 2026 |
| Linktamils Limited | Information & communication | 2024 |
| Lintel Analytics Ltd | Administrative & support | 2014 |
| Lintonhill Ltd | Construction | 2008 |
| LIO Software Ltd | Professional & scientific | 2016 |