| Leafield Athletic Ladies FC Ltd | Arts & recreation | 2025 |
| Leah Jones 2025 Limited | Extraterritorial | 2011 |
| Leamington Court Management Company Limited | Households | 1982 |
| Lean Consultancy (Solihull) Limited | Professional & scientific | 2015 |
| Leaner Program Management Limited | Administrative & support | 2021 |
| Leanneslaundry Ltd | Administrative & support | 2025 |
| Leap IT Limited | Information & communication | 2004 |
| Leapfrog Real Estate Limited | Real estate | 2019 |
| Leapfrog Sports Franchising Ltd | Arts & recreation | 2019 |
| Leapfrog Sports Ltd | Arts & recreation | 2014 |
| Leaping Frogs Ltd | Professional & scientific | 2008 |
| Learig Property Management Ltd | Real estate | 2020 |
| Learn & Play Limited | Education | 2014 |
| Learning DNA Clinical Services Ltd | Health & social care | 2026 |
| Learning DNA Ltd | Administrative & support | 2024 |
| Lease Portfolio Management Limited | Professional & scientific | 1991 |
| Leased and Tenanted Pubs 1 Limited | Hospitality | 2019 |
| Leased and Tenanted Pubs 2 Limited | Hospitality | 2019 |
| LED FX AV Ltd | Administrative & support | 2023 |
| Leda Solutions Limited | Construction | 2012 |
| LEE 2022 Ltd | Real estate | 2022 |
| LEE Brotherhood Golf Ltd | Education | 2021 |
| LEE Scolding Hairdressing Limited | Other services | 2011 |
| Lee-Za Properties Ltd | Hospitality | 2025 |
| Lee-Za UK Limited | Real estate | 2014 |
| Leeks Healthcare (Midlands) Limited | Health & social care | 2025 |
| Leequestrian Ltd | Agriculture & fishing | 2025 |
| Left Field Beer Limited | Hospitality | 2016 |
| Legacy Habitat Banks Ltd | Professional & scientific | 2022 |
| Legacy Marketing Ltd | Professional & scientific | 2023 |
| Legacyos Limited | Administrative & support | 2025 |
| Legal Accounts Limited | Professional & scientific | 2011 |
| Legal Compliance Consultants Limited | Professional & scientific | 2018 |
| Legatum Legacy Limited | Administrative & support | 2011 |
| Lehal Management Ltd | Real estate | 2016 |
| Leica Biosystems Newcastle Limited | Professional & scientific | 1987 |
| Leica Microsystems (UK) Limited | Wholesale & retail | 1949 |
| Leica Microsystems Cambridge Limited | Professional & scientific | 1992 |
| Leicester Bowel Clinic LLP | | 2010 |
| Leightrose Limited | Professional & scientific | 2013 |
| Lenders (UK) Limited | Administrative & support | 1994 |
| Length & Strength Ltd | Health & social care | 2016 |
| LEO & Jenny Holdings Ltd | Education | 2024 |
| Leon Building Services (Evesham) Limited | Construction | 1994 |
| Leon Building Services Holdings Limited | Financial services | 2023 |
| Leon Building Services Limited | Financial services | 2012 |
| Leonwhitesolutions Ltd | Information & communication | 2017 |
| LES Jones Limited | Information & communication | 2008 |
| LET a Room Ltd | Real estate | 2025 |
| Letco Letting Agents Ltd | Real estate | 2020 |
| Lets BE Active Ltd | Education | 2014 |
| Letsride West Midlands Limited | Transport & logistics | 2021 |
| Lettington Miller Limited | Administrative & support | 2019 |
| Leung and SON Construction Co. Ltd | Construction | 2025 |
| Leva Digital Limited | Professional & scientific | 2026 |
| Level 23 Ltd | Education | 2016 |
| Level UP Barbers Ltd | Other services | 2025 |
| Lewis Abbott Limited | Wholesale & retail | 1945 |
| Lewis Exterior Cleaning Ltd | Administrative & support | 2025 |
| Lewis Financial Consulting Ltd | Professional & scientific | 2026 |
| Lewis John Limited | Information & communication | 2017 |
| Lewthwaite Neurology Limited | Health & social care | 2014 |
| Lextyn Ltd | Information & communication | 2026 |
| Leydon Electrical Ltd | Construction | 2014 |
| Leys Field (Oxhill) Management Company Limited | Households | 2018 |
| LFI Midlands Ltd | Administrative & support | 2023 |
| LG Solutions & Consulting Limited | Administrative & support | 2014 |
| LG Team Shares Ltd | Financial services | 2023 |
| LGD Ltd | Other services | 2022 |
| LGH Homes Ltd | Real estate | 2023 |
| LGS Hair Clinic Limited | Health & social care | 2016 |
| LGS Hair Tattooing Ltd | Other services | 2022 |
| LGS Training London Ltd | Other services | 2022 |
| Lgss Limited | Administrative & support | 2012 |
| LH & DH Real Estate Limited | Real estate | 2020 |
| LH Communications Limited | Professional & scientific | 2017 |
| LH Stratford Limited | Hospitality | 2026 |
| LHA Represents Limited | Professional & scientific | 2012 |
| Lhch Limited | Health & social care | 2026 |
| LHR Group Ltd | Real estate | 2021 |
| LHR Media Production Ltd | Information & communication | 2024 |
| Lhughes Limited | Manufacturing | 2022 |
| Li's Bake & Beyond Ltd | Manufacturing | 2024 |
| Li's Property Investment Ltd | Real estate | 2021 |
| Libbard Ltd | Real estate | 2014 |
| Liberty Property Trust UK Limited | Construction | 2005 |
| Licet Ventures Limited | Professional & scientific | 1996 |
| Lickey Properties Ltd | Real estate | 2025 |
| LID CLO Ltd | Wholesale & retail | 2023 |
| LID Project Ltd | Professional & scientific | 2015 |
| Life Path Wills & Lpa's Ltd | Administrative & support | 2025 |
| Life Saver's Housing Ltd | Real estate | 2023 |
| Lift Giant Limited | Administrative & support | 2021 |
| Lift Group Ventures Limited | Financial services | 2026 |
| Lift Recruitment Limited | Administrative & support | 2024 |
| Lift YOU Hire Ltd | Transport & logistics | 2024 |
| Light by LED Ltd | Administrative & support | 2012 |
| Light Hall School | Education | 2011 |
| Light House Consulting Partners Ltd | Professional & scientific | 2025 |
| Lightermans Place (Maldon) Management Company Limited | Extraterritorial | 2015 |