| LET Right Holdings Limited | Financial services | 2019 |
| LET Safe Limited | Construction | 2024 |
| Let's Heat SW Ltd | Construction | 2024 |
| LET4LET Ltd | Real estate | 2025 |
| Letbe Recruitment Ltd | Public administration | 2020 |
| Letflare Ltd | Real estate | 2024 |
| Letm Properties Ltd | Real estate | 2025 |
| Letman Associates Ltd | Transport & logistics | 2022 |
| Letman Associates Property Limited | Real estate | 2025 |
| Letmc Holdings Limited | Financial services | 2017 |
| Letoon Holding Ltd | Health & social care | 2023 |
| Letrika Ltd | Wholesale & retail | 2025 |
| Lets Go Britain II Ltd | Information & communication | 2023 |
| Lets Inspect Property Limited | Real estate | 2013 |
| Lets Rent a Home Ltd | Real estate | 2018 |
| Lets Talk Finance Limited | Administrative & support | 2017 |
| Letsfun Ltd | Information & communication | 2025 |
| Letskonet Web Design Company Ltd | Information & communication | 2024 |
| Letthemseecake Limited | Wholesale & retail | 2020 |
| Letting Property Limited | Real estate | 2013 |
| Lettings Angels Limited | Real estate | 2014 |
| LETTINGS2SALES Ltd | Real estate | 2014 |
| Lettoi Commerce Ltd | Manufacturing | 2025 |
| Letts Inceptions Ltd | Real estate | 2018 |
| Lettutree Ltd | Extraterritorial | 2021 |
| Letyco Limited | Information & communication | 2017 |
| Letz Build Ltd | Construction | 2025 |
| Letza Ltd | Hospitality | 2025 |
| Let’S Build SW Ltd | Construction | 2023 |
| Leung Jing Limited | Hospitality | 2015 |
| Levant Book Cafe Ltd | Wholesale & retail | 2013 |
| Levant Stone & Tiles Ltd | Manufacturing | 2025 |
| Levant Stone Ltd | Manufacturing | 2023 |
| Levante Holdings Ltd | Real estate | 2015 |
| Level 9K Limited | Professional & scientific | 2021 |
| Level UP Associates Limited | Administrative & support | 2024 |
| Level UP Coaching Ltd | Education | 2021 |
| Level UP Vertrieb | Information & communication | 2021 |
| Levels Beyond Ltd | Other services | 2025 |
| Levelupper Ltd | Information & communication | 2025 |
| Leven Trading Limited | Information & communication | 2016 |
| Leverage Workplace Motivation Ltd | Administrative & support | 2021 |
| Levimay Rail Limited | Construction | 2016 |
| Levin - I SEE YOU Ltd | Wholesale & retail | 2019 |
| Levitate Online Ltd | Professional & scientific | 2020 |
| Levitt Commercial Consultants Ltd | Professional & scientific | 2012 |
| Levl Ltd | Administrative & support | 2019 |
| LEW JAY Holdings Limited | Financial services | 2025 |
| Lewbard Engineering Services Ltd | Wholesale & retail | 2023 |
| Leweil Ltd | Extraterritorial | 2012 |
| Lewes Glazing Ltd | Construction | 2024 |
| Lewicon Limited | Administrative & support | 2014 |
| Lewis & Lewis Limited | Professional & scientific | 1996 |
| Lewis & Perkins Limited | Construction | 2012 |
| Lewis and SON Construction Ltd | Construction | 2026 |
| Lewis Ballard Limited | Professional & scientific | 2009 |
| Lewis Barker Ltd | Information & communication | 2025 |
| Lewis Cooke Web Ltd | Information & communication | 2014 |
| Lewis Financial Planning & Wealth Management Ltd | Financial services | 2022 |
| Lewis Giles Art Limited | Arts & recreation | 2019 |
| Lewis HR Consultancy Ltd | Professional & scientific | 2026 |
| Lewis LOG Cabins Ltd | Construction | 2023 |
| Lewis Logistic Ltd | Transport & logistics | 2016 |
| Lewis Motion Ltd | Information & communication | 2026 |
| Lewis Motors Limited | Wholesale & retail | 2005 |
| Lewis Site Services Ltd | Construction | 2012 |
| Lewisham Coffee Limited | Hospitality | 2017 |
| Lewland Ltd | Real estate | 2022 |
| Lewtons Psychology Practice Limited | Health & social care | 2022 |
| LEX Associated Ltd | Other services | 2022 |
| LEX Corpus Ltd | Extraterritorial | 2025 |
| LEX Dominus Ltd | Professional & scientific | 2018 |
| LEX Futurus (UK) Blockchain Regtech & Law Limited | Professional & scientific | 2018 |
| LEX Holdings Limited | Professional & scientific | 2009 |
| LEX House Limited | Professional & scientific | 2016 |
| LEX Interiors Ltd | Administrative & support | 2017 |
| LEX Trading Ltd | Wholesale & retail | 2024 |
| Lex-Anabrenda & Co. Ltd | Health & social care | 2019 |
| Lex-Impex Ltd | Transport & logistics | 2019 |
| Lexalloys Ltd | Wholesale & retail | 2018 |
| Lexan Construction Ltd | Construction | 2020 |
| Lexan Group Limited | Manufacturing | 2017 |
| Lexcore Prestige Limited | Other services | 2017 |
| Lexdech Limited | Information & communication | 2019 |
| Lexgable Limited | | 1973 |
| Lexi Ladies Academy Ltd | Information & communication | 2016 |
| Lexintervest Ltd | Administrative & support | 2014 |
| Lexisnexis Risk Solutions UK Limited | Information & communication | 2010 |
| Lexon (G.B.) Limited | Manufacturing | 2015 |
| Lexoss Ltd | Administrative & support | 2019 |
| Lexothegreat Limited | Health & social care | 2019 |
| Lexsor International Limited | Wholesale & retail | 2024 |
| Leydens London Ltd | Professional & scientific | 2019 |
| Leydon Engineering Limited | Professional & scientific | 2016 |
| Leylapp Ltd | Wholesale & retail | 2025 |
| Leyshon Leasing Ltd | Administrative & support | 2022 |
| Lezerco UK Ltd | Wholesale & retail | 2022 |
| LFB Cymru CYF | Administrative & support | 2009 |
| Lfeyho Trading Ltd | Wholesale & retail | 2025 |
| LFT Maintenance Ltd | Construction | 1994 |