| LB Skin Limited | Other services | 2026 |
| LB Technics Limited | Other services | 2026 |
| LBP Contracts Limited | Construction | 2023 |
| LBP Training Consultants Ltd | Education | 2021 |
| LC Fire Ltd | Construction | 2024 |
| LC Medcare Solutions Ltd | Health & social care | 2024 |
| LC Professional Ltd | Construction | 2024 |
| LC Trade Limited | Professional & scientific | 2026 |
| LC Vending Maintenance Ltd | Hospitality | 2025 |
| LC Vending Solutions Ltd | Wholesale & retail | 2013 |
| LCF Electrical Ltd | Construction | 2023 |
| Lchi Limited | Construction | 2017 |
| LCM Surgical Ltd | Other services | 2023 |
| LCS Railway Engineering Limited | Construction | 2013 |
| LCT London Limited | Other services | 2018 |
| LD MD BTL 200828 Ltd | Administrative & support | 2020 |
| LD Richard Limited | Manufacturing | 2015 |
| Ldkb Limited | Construction | 2025 |
| LDN Catering Limited | Hospitality | 2024 |
| LDP Business Services Ltd | Professional & scientific | 2021 |
| LDR Auto Car Care Ltd | Wholesale & retail | 2024 |
| LDS Hire Ltd | Administrative & support | 2020 |
| LE Beau Photography Limited | Professional & scientific | 2025 |
| LE Financial Limited | Professional & scientific | 2018 |
| LE Purple Management Ltd | Hospitality | 2025 |
| LE Wine Spirit Ltd | Wholesale & retail | 2022 |
| Leabrook Civil Limited | Professional & scientific | 2016 |
| Leadenhall Consulting Limited | Administrative & support | 2011 |
| LEADSS9 Limited | Information & communication | 2024 |
| Leadstead Services Limited | Information & communication | 2022 |
| Lean for Life Coaching Limited | Arts & recreation | 2025 |
| Lean SIX Search Group Limited | Administrative & support | 2024 |
| LED Corner Co UK Limited | Wholesale & retail | 2015 |
| Ledhar Properties Ltd | Real estate | 2026 |
| LEE Chapel Multi Academy Trust | Education | 2011 |
| LEE Masters Osteopaths Limited | Health & social care | 2012 |
| LEE Tuition Ltd | Education | 2025 |
| LEE Utilities Limited | Administrative & support | 2012 |
| Leeming Brothers Ltd | Other services | 2011 |
| Leepops Ltd | Wholesale & retail | 2022 |
| Leerudgley Ltd | Construction | 2011 |
| Legacy Circle Ltd | Professional & scientific | 2025 |
| Legends Pool & Sports Bar Limited | Other services | 2023 |
| Legra Capital Solutions Limited | Professional & scientific | 2023 |
| Legra Marketing Ltd | Professional & scientific | 2020 |
| Leigh Garden Rooms Limited | Other services | 2023 |
| Leigh on Sea Heating and Plumbing Ltd | Construction | 2024 |
| Leigh Park Road Developments Limited | Construction | 2021 |
| Leigh Stairways Limited | Manufacturing | 1999 |
| Leigh-On-Sea Skip Hire Limited | Transport & logistics | 2017 |
| Lekbim Services Ltd | Information & communication | 2021 |
| Lekshmi Investments Ltd | Health & social care | 2022 |
| Lemay Surveyors Limited | Professional & scientific | 2023 |
| Lenlo Limited | Water & waste | 2025 |
| Lenval Properties Limited | Real estate | 2002 |
| LEO Basildon Limited | Hospitality | 2022 |
| LEO Global Services Ltd | Education | 2017 |
| Leocleaning Impex Ltd | Wholesale & retail | 2025 |
| Leoma Consulting Ltd | Administrative & support | 2017 |
| Leon Trucks Ltd | Transport & logistics | 2020 |
| Leonard Payton Limited | Construction | 1948 |
| Leonard Property Consultancy Ltd | Professional & scientific | 2023 |
| Leovest Human Care Limited | Public administration | 2023 |
| Leracris Ltd | Health & social care | 2015 |
| Letora Group Limited | Real estate | 2025 |
| Letorsell Ltd | Real estate | 2014 |
| Lets Glow Crazy Ltd | Wholesale & retail | 2025 |
| Letsmart Properties Limited | Real estate | 2025 |
| Letsure UK Limited | Real estate | 2007 |
| Lettings Software Limited | Information & communication | 2023 |
| Leuss Xlce Limited | Health & social care | 2022 |
| Levavo Limited | Wholesale & retail | 2012 |
| Levic LV Limited | Construction | 2022 |
| Levitation Services Ltd | Construction | 2023 |
| LEW and Co Ltd | Administrative & support | 2020 |
| Lewis Burgin Construction Consultancy Limited | Construction | 2026 |
| Lewis Capital Estates Limited | Real estate | 2025 |
| Lewis Hellmann Homes Ltd | Real estate | 2023 |
| Lewis Property Essex Limited | Real estate | 2025 |
| Lewis ROW Limited | Other services | 2017 |
| Lexa Construction Limited | Construction | 2011 |
| Leyton Lighting Limited | Manufacturing | 2003 |
| Leytonbrook Hills Properties Limited | Real estate | 2022 |
| LG Projects (London) Ltd | Construction | 2020 |
| LGR Utilities Ltd | Construction | 2023 |
| LH Improvements Limited | Construction | 2021 |
| Lhgc Holdings Limited | Financial services | 2024 |
| LI Drylining Ltd | Construction | 2023 |
| Life Racing Limited | Manufacturing | 2000 |
| Life Skills Community CIC | Education | 2026 |
| Light Kongomanyi Glory (LKG) Accountants Ltd | Professional & scientific | 2024 |
| Light on Design Ltd | Professional & scientific | 2019 |
| Light Visuals Ltd | Manufacturing | 2008 |
| Lighthouse Services Limited | Financial services | 2001 |
| Lightpath Consulting Limited | Information & communication | 2012 |
| Lightpro Energy Ltd | Construction | 2024 |
| Lillymarly Designs Limited | Health & social care | 2021 |
| Lillytech Limited | Information & communication | 2025 |
| Lilscandleco Ltd | Wholesale & retail | 2026 |
| Limera Ltd | Construction | 2026 |