| Ldrew Ltd | Other services | 2020 |
| LDW Consulting & Advisory Ltd | Administrative & support | 2026 |
| LE Papillon Patisserie UK (Holdings) Limited | Wholesale & retail | 2006 |
| LEA Court (Harpenden) Limited | Administrative & support | 1961 |
| Lead From Within Ltd | Information & communication | 2020 |
| Lead Training & Consulting Ltd | Professional & scientific | 2010 |
| Leadlinka Ltd | Information & communication | 2026 |
| Leahs Archive Ltd | Wholesale & retail | 2026 |
| Leahy GI Services Ltd | Health & social care | 2023 |
| Leaming Consultancy Limited | Financial services | 2020 |
| Leamy Manders Limited | Professional & scientific | 2017 |
| Leap Physiotherapy Ltd | Health & social care | 2020 |
| Leapsquare Corporate Services Limited | Professional & scientific | 1989 |
| Learning Just Became Easier Ltd | Administrative & support | 2012 |
| Leaseline Vehicle Management Ltd | Financial services | 2006 |
| Lednor Accounting Limited | Professional & scientific | 2023 |
| Lednor Liveries Limited | Agriculture & fishing | 2025 |
| LEE Allen Consulting Ltd | Information & communication | 2015 |
| LEE Brothers Associates Limited | Professional & scientific | 2011 |
| LEE Roofing Service Limited | Construction | 2025 |
| Leeannaswish CIC | Health & social care | 2021 |
| Leedie Limited | Wholesale & retail | 2023 |
| Leenix Ltd | Information & communication | 2015 |
| LEF Educational Services Ltd | Administrative & support | 2022 |
| Leftfield Entertainment Limited | Professional & scientific | 2014 |
| Legacy Outdoor Living Ltd | Administrative & support | 2026 |
| Legacy Property Fund Limited | Real estate | 2008 |
| Legals 4 Lawyers Limited | Administrative & support | 2005 |
| Legends MAN Grooming Ltd | Other services | 2026 |
| Legends Series Ltd | Arts & recreation | 2025 |
| Leijgrave Carpentry and Joinery Ltd | Manufacturing | 2024 |
| Leisair Limited | Financial services | 1979 |
| Lellb Properties Ltd | Real estate | 2026 |
| Lemnn Ltd | Manufacturing | 2025 |
| Lena Schmidt Ltd | Information & communication | 2020 |
| LEO Film Productions Ltd | Information & communication | 2026 |
| LEO Holborn Services Limited | Wholesale & retail | 1999 |
| Leo.M Property Management Ltd | Wholesale & retail | 2026 |
| Leopard Digital Limited | Information & communication | 2021 |
| Leoville Partners Ltd | Professional & scientific | 2021 |
| LES Petits Ecoliers Ltd | Education | 2012 |
| Lesmar Limited | Professional & scientific | 1947 |
| Lester Solutions Ltd | Information & communication | 2019 |
| LET ME Limited | Real estate | 2008 |
| Lets Leap Sports Academy Ltd | Education | 2019 |
| Lettings ETC Ltd | Real estate | 2022 |
| Leumas C Ltd | Education | 2022 |
| Leung LI Ltd | Information & communication | 2015 |
| Levandi Limited | Wholesale & retail | 2025 |
| Levensoft Services Limited | Information & communication | 2015 |
| Levig Consultancy Services Limited | Information & communication | 2010 |
| Levitategym Limited | Arts & recreation | 2022 |
| Lewis Junior Ltd | Wholesale & retail | 2020 |
| Lewis Property Maintenance Ltd | Construction | 2015 |
| LEX Electrical Contractors Ltd | Construction | 2024 |
| Leyshon Enterprise Ltd | Professional & scientific | 2024 |
| LF Distribution Ltd | Wholesale & retail | 2025 |
| Lftc Limited | Arts & recreation | 2024 |
| Lglam Ltd | Wholesale & retail | 2025 |
| LH Goalkeeping Limited | Arts & recreation | 2023 |
| LHF Group Limited | Hospitality | 2019 |
| Lhss Venues Ltd | Hospitality | 2024 |
| Lianne Powell Aesthetics Ltd | Health & social care | 2024 |
| Liberty Plastics Limited | Manufacturing | 1992 |
| Libre Limited | Professional & scientific | 2019 |
| Lifang London Vision Technology Limited | Professional & scientific | 2018 |
| Life Goddess Kingly Court Limited | Hospitality | 2014 |
| Life Time Builds Ltd | Construction | 2025 |
| Lifelodestar Ltd | Wholesale & retail | 2021 |
| Lifestreamdsa Ltd | Professional & scientific | 2024 |
| Lifetime Assure Limited | Extraterritorial | 2011 |
| Lifetime Financial Management Limited | Financial services | 1998 |
| Lifetime FS Limited | Financial services | 2013 |
| Lifetime Partners Limited | Extraterritorial | 2024 |
| Lifetime Wealth Management Limited | Financial services | 2003 |
| Lift Engineering Limited | Construction | 2019 |
| Light Bulb Research Ltd | Other services | 2017 |
| Lighthouse Services (UK) Limited | Professional & scientific | 2004 |
| Lightoaks Gundogs Limited | Agriculture & fishing | 2025 |
| Lightsoul Limited | Professional & scientific | 2026 |
| Lilliano Estate Ltd | Real estate | 2025 |
| Lilo Homes Limited | Real estate | 2022 |
| Lily Alley Ltd | Wholesale & retail | 2012 |
| Lime Hire Ltd | Administrative & support | 2019 |
| Lime Production Solutions Ltd | Administrative & support | 2012 |
| Limestone Gallery (UK) Limited | Construction | 2011 |
| Liminal State Limited | Professional & scientific | 2025 |
| Limitsys Ltd | Information & communication | 2012 |
| Limitx Ltd | Wholesale & retail | 2025 |
| Lincolnshire County Couriers Limited | Transport & logistics | 1999 |
| Linda Dajci Ltd | Real estate | 2024 |
| Lindar Media Limited | Information & communication | 2014 |
| Linea Vitalis Ltd. | Health & social care | 2012 |
| Lingwood Design Architects Limited | Professional & scientific | 2014 |
| Links Multi Academy Trust | Education | 2012 |
| Linney Tuning Limited | Wholesale & retail | 2002 |
| Lionel Wallace Limited | Real estate | 2015 |
| Lioness Productions Limited | Information & communication | 2008 |
| Lions (Schools) Limited | Real estate | 2023 |
| Lions Call Center Ltd | Wholesale & retail | 2023 |