| Lemos Architecture Limited | Professional & scientific | 2023 |
| Lena Thakrar Consulting Limited | Professional & scientific | 2018 |
| Lengha Limited | Professional & scientific | 2010 |
| Lenihan Hair Limited | Other services | 2015 |
| Lenoka Ltd | Professional & scientific | 2019 |
| Lenoka Property Ltd | Real estate | 2023 |
| Lensco (London) Limited | Professional & scientific | 1954 |
| LEO Properties Ltd | Extraterritorial | 2009 |
| LEO Store Ltd | Wholesale & retail | 2025 |
| Leone Olins Limited | Extraterritorial | 2009 |
| LES Couilles DU Chien Limited | Wholesale & retail | 2011 |
| Leslie & Co Legacy Limited | Financial services | 2025 |
| Leslie & Company Residential Limited | Real estate | 2020 |
| LET US Game Limited | Information & communication | 2023 |
| LET US Sell Limited | Wholesale & retail | 2020 |
| Letchmore Consulting Limited | Professional & scientific | 2010 |
| Letchmore Property Limited | Real estate | 2008 |
| Lethamyard Ltd | Wholesale & retail | 2007 |
| Lets AVK Limited | Real estate | 2025 |
| Lets Party Kids Limited | Administrative & support | 2016 |
| Letsen Financial Holdings Limited | Real estate | 1958 |
| Letsen Property Investments Limited | Real estate | 1963 |
| Letsinvest Ltd | Real estate | 2007 |
| Letta London Limited | Construction | 2018 |
| Lettings of London TOO Ltd. | Administrative & support | 2018 |
| Levitate Solutions Ltd | Administrative & support | 2020 |
| Lewin Crown Ltd | Construction | 2020 |
| Lewis Harrison Limited | Extraterritorial | 2020 |
| Lewis Investments (London) Limited | Real estate | 2022 |
| Lftt Casting Ltd | Other services | 2024 |
| LG Halai Investments Limited | Other services | 2024 |
| Lgbtiq+ Outside Community Interest Company | Administrative & support | 2017 |
| LHR Construction Ltd | Construction | 2009 |
| LI Innovation Limited | Information & communication | 2024 |
| Liam Consults Ltd | Professional & scientific | 2009 |
| Liberty Care Holdings Limited | Financial services | 2023 |
| Liberty Housing Solutions Ltd | Real estate | 2024 |
| Liberty Property Finance Limited | Financial services | 2000 |
| Life Outdoors Ltd | Wholesale & retail | 2018 |
| Lifehouse (London) Limited | Construction | 2009 |
| Lifestyle Lettings & Management Ltd | Real estate | 2023 |
| Lifestyle Professional Services Ltd | Professional & scientific | 2022 |
| Lifestyle Property People Ltd | Real estate | 2016 |
| Lifestyle Refurbishments Ltd | Construction | 2017 |
| Lifestyle UK Holdco Limited | Financial services | 2024 |
| Lifting GAS Ltd | Professional & scientific | 2018 |
| Lifting&Uas Ltd | Information & communication | 2026 |
| Ligature Limited | Information & communication | 2011 |
| Light 24 Ltd | Health & social care | 2021 |
| Lightbulb Moments Services Limited | Construction | 2024 |
| Lighthouse Capital Group Limited | Real estate | 2018 |
| Ligular (General Merchants) Limited | Real estate | 1974 |
| Likud UK Limited | Professional & scientific | 2025 |
| Lili Autos Limited | Wholesale & retail | 2015 |
| Lily & Damian Hotels Ltd | Real estate | 2024 |
| Lily and Ribbon Limited | Wholesale & retail | 2017 |
| Lilywell Investments Ltd | Real estate | 2019 |
| Limebay Properties Limited | Real estate | 2016 |
| Limebridge Investments Limited | Real estate | 2023 |
| Limelite Accommodation Ltd | Hospitality | 2023 |
| Limitbrook Limited | Construction | 1986 |
| Lincoln Holdings Limited | Real estate | 2015 |
| Linden Investments Europe Ltd | Real estate | 2008 |
| Linea Investment Properties Limited | Real estate | 2023 |
| Lineafashion.Com Limited | Wholesale & retail | 2021 |
| Linear Design and Build Limited | Construction | 2018 |
| Linear Insight Ltd | Professional & scientific | 2011 |
| Lineas Developments Ltd | Construction | 2025 |
| Lineforge Limited | Other services | 2002 |
| Lion Valley Limited | Information & communication | 2018 |
| Lionel H.Morris Limited | Real estate | 1960 |
| Liquid Bubble Group Limited | Professional & scientific | 2014 |
| Liquid Bubble Limited | Information & communication | 2011 |
| Liquid Bubble Media Ltd | Manufacturing | 1999 |
| Liquid Bubble Print Limited | Other services | 2014 |
| Liquid Circle Ltd | Arts & recreation | 2007 |
| Liquidity Concepts Ltd | Professional & scientific | 2017 |
| Lisa Halpern PR Limited | Professional & scientific | 2022 |
| Lisa Lodge Management Company Limited | Households | 1970 |
| Lisu Moshi Limited | Professional & scientific | 2009 |
| Little Acorns Real Estate Ltd | Real estate | 2015 |
| Little Aisha Canning Town Ltd | Education | 2025 |
| Little Aisha Finchley Ltd | Education | 2025 |
| Little Aisha Hammersmith Ltd | Education | 2025 |
| Little Aisha Harrow Ltd | Education | 2025 |
| Little Aisha Neasden Ltd | Education | 2025 |
| Little Aisha Stanmore and Pinner Ltd | Education | 2025 |
| Little Aisha Stonebridge Ltd | Education | 2025 |
| Little Avanti Nursery Ltd | Education | 2025 |
| Little Big Leaders Limited | Education | 2014 |
| Little Cassiobury House Ltd | Real estate | 2023 |
| Little Entertainment Limited | Information & communication | 2018 |
| Little Excursions Limited | Administrative & support | 2024 |
| Little Lumos Nursery Limited | Education | 2025 |
| Little Peartree Properties Ltd | Real estate | 2024 |
| Little Pebbles Limited | Education | 2011 |
| Little Tinks Catering Limited | Hospitality | 2013 |
| Litton Property Ltd | Real estate | 2020 |
| Livane Ltd | Wholesale & retail | 2025 |
| Live & Maintain Ltd | Wholesale & retail | 2022 |