| LEO Maritime Ltd | Professional & scientific | 2018 |
| LEO Nickolls Design Ltd | Administrative & support | 2011 |
| LEO Russell Promotions Limited | Other services | 2024 |
| LEO Zane Acquisitions Limited | Real estate | 2021 |
| Leokam Healthcare Specialists Ltd | Health & social care | 2023 |
| Leominster Food Limited | Hospitality | 2019 |
| Leonard Court Management Company Norfolk Limited | Real estate | 2024 |
| Leonard James Property Limited | Real estate | 2024 |
| Leone Capital Investment Ltd | Real estate | 2024 |
| Leonis Talent Ltd | Administrative & support | 2025 |
| Leonz Ltd | Wholesale & retail | 2022 |
| Leopard Holdings Ltd | Extraterritorial | 2022 |
| Leopard Moth Holdings Ltd | Financial services | 2017 |
| Leopolis Properties Limited | Real estate | 2014 |
| Leoware Limited | Agriculture & fishing | 1962 |
| LES Cooper Builders Ltd | Construction | 2003 |
| LES Gets Limited | Financial services | 2022 |
| Lessons Near ME Limited | Education | 2011 |
| Let&Go Limited | Real estate | 2022 |
| Let's GET OUT C.I.C. | Education | 2020 |
| Let's GET OUT Group Ltd | Education | 2024 |
| Let's Talk More Ltd | Other services | 2017 |
| Letheringsett Farms Limited | Agriculture & fishing | 2003 |
| Lets GET IT OM Ltd | Wholesale & retail | 2022 |
| Lets Go Cloud Ltd | Information & communication | 2018 |
| Lets Go Removals and Storage Ltd | Transport & logistics | 2026 |
| Letsinsure Limited | Financial services | 2022 |
| Letsrenovate Ltd | Real estate | 2023 |
| Lettasafe Ltd | Manufacturing | 2010 |
| Letterbox Property Ltd | Real estate | 2022 |
| Leuchland Energy Centre Limited | Energy | 2024 |
| Level Change Limited | Transport & logistics | 2020 |
| Level UP EXP Ltd | Manufacturing | 2025 |
| Level UP Volleyball Ltd | Wholesale & retail | 2024 |
| Levelling UP | Arts & recreation | 2021 |
| Levelz Energy Ltd | Wholesale & retail | 2025 |
| Levenmere Limited | Real estate | 1987 |
| Leverets Advocacy Limited | Professional & scientific | 2017 |
| Leveridges Limited | Other services | 2019 |
| Leveridges Salon Limited | Other services | 2017 |
| Leveton & Sons(Norwich)Limited | Other services | 1948 |
| Leviu Ltd | Transport & logistics | 2017 |
| Lewis & Co. Street Eats Limited | Hospitality | 2025 |
| Lewis & Sons Home Improvements Ltd | Construction | 2025 |
| Lewis Cook Independent Funeral Home Ltd | Other services | 2023 |
| Lewis Fackrell Wedding Photography Ltd | Professional & scientific | 2024 |
| Lewis Frank Limited | Professional & scientific | 2009 |
| Lewis Freeman Limited | Information & communication | 2021 |
| Lewis G Ltd | Professional & scientific | 2026 |
| Lewis George Property Ltd | Real estate | 2024 |
| Lewis Michael Mortgages Limited | Financial services | 2023 |
| Lewis Osborne Ltd | Professional & scientific | 2023 |
| Lewis Williams Coaching Ltd | Other services | 2025 |
| Lewis Williams Consulting Ltd | Other services | 2025 |
| Lewiskeyes Developements (Holdings) Ltd | Financial services | 2018 |
| Lexact Legal Recruitment Ltd | Administrative & support | 2025 |
| Lexol Ltd | Administrative & support | 2026 |
| Lexxika Ltd | Professional & scientific | 2018 |
| LFM Services UK Limited | Manufacturing | 2021 |
| Lfree Ltd | Health & social care | 2019 |
| LG & Co Consultancy Limited | Professional & scientific | 2024 |
| LG Property Management Limited | Real estate | 2025 |
| LG Solar Scaffolding Ltd | Construction | 2024 |
| LGA Property Management Limited | Real estate | 2018 |
| LGB Media Ltd | Other services | 2024 |
| LGB Plumbing & Heating Ltd | Construction | 2014 |
| Lgcc Ltd | Administrative & support | 2019 |
| LGL Consulting Limited | Financial services | 2010 |
| LHC Developers (Holdings) Ltd | Financial services | 2025 |
| LHC Developers Ltd | Construction | 2021 |
| LHE Robson FIC2 Limited | Financial services | 2023 |
| LHI Consulting Solutions Ltd. | Professional & scientific | 2016 |
| Lhpt Properties Limited | Construction | 2015 |
| LHR London Ltd | Hospitality | 2019 |
| LHT Construction Ltd | Construction | 2025 |
| Liam Last Ltd | Professional & scientific | 2023 |
| Liam Stubbs Photography Limited | Professional & scientific | 2023 |
| Liar Brands Ltd | Wholesale & retail | 2023 |
| Liberator Group Limited | Hospitality | 2024 |
| Liberator Residents Management Company Ltd | Administrative & support | 2022 |
| Libertas Assets Ltd | Real estate | 2024 |
| Libertas Ecom Ltd | Wholesale & retail | 2026 |
| Libertas Hold Co Ltd | Financial services | 2026 |
| Libertas Investments Ltd | Financial services | 2022 |
| Libertas NE Ltd | Construction | 2026 |
| Liberty Build Homes Limited | Construction | 2015 |
| Liberty Sky Ltd | Other services | 2018 |
| Libra Holdings Ltd | Administrative & support | 2016 |
| Library Close Management Ltd | Real estate | 2023 |
| Lichfield Indian Limited | Hospitality | 2021 |
| Lido Sonia Limited | Health & social care | 2019 |
| Lids of London Limited | Wholesale & retail | 2022 |
| Life at Home Limited | Other services | 2013 |
| Life Care (UK) Limited | Health & social care | 1992 |
| Life Content 7 Ltd | Information & communication | 2023 |
| Life Safety Alarm Services Ltd | Professional & scientific | 2022 |
| Life Solutions UK Ltd | Wholesale & retail | 2006 |
| Lifeadvicenorfolk Ltd | Financial services | 2018 |
| Lifecrest Ltd | Professional & scientific | 2013 |
| Lifecrest Relocation Ltd | Real estate | 2024 |