| Landscapingbycat Ltd | Administrative & support | 2025 |
| Landstock Construction Ltd | Construction | 2004 |
| Landstock Developments (Northern) Ltd | Construction | 1997 |
| Landymoor Ltd | Professional & scientific | 2017 |
| Lane & Co Mortgages Ltd | Financial services | 2025 |
| Lanford Designs Limited | Construction | 1975 |
| Langdon Developments Ltd | Real estate | 2016 |
| Langham Management Co. (Norfolk) Ltd | Construction | 2011 |
| Langley Components (Maidenhead) Limited | Manufacturing | 1966 |
| Langley Creative Limited | Professional & scientific | 2012 |
| Langton Green (Taplow) Management Limited | Households | 2017 |
| Language Adventurer Ltd | Education | 2012 |
| Lansdowne Court Taplow (Freehold) Limited | Real estate | 2018 |
| Lanux House Management Ltd | Households | 2021 |
| Lanza Foods Ltd | Wholesale & retail | 2007 |
| Lapis Heaven Ltd | Wholesale & retail | 2024 |
| Laramie Medical Solutions Limited | Administrative & support | 2017 |
| Larmonte Group Limited | Administrative & support | 2006 |
| Laser Score Limited | Wholesale & retail | 2020 |
| Lasercut Works Ltd | Arts & recreation | 2012 |
| Lasertek Ltd | Manufacturing | 2016 |
| Lashandbrowline Ltd | Education | 2020 |
| Lassell Gardens Management Company Limited | Households | 1986 |
| Last MAN Named Gary Ltd | Professional & scientific | 2024 |
| Last Resort Civilian Defence Limited | Manufacturing | 2025 |
| Lateco SP ZOO Ltd | Construction | 2009 |
| Latentplane Ltd | Information & communication | 2020 |
| Latitude 40 Enterprises Limited | Administrative & support | 1975 |
| Latymer House Freehold Limited | Households | 2012 |
| Laufin Properties Limited | Real estate | 2021 |
| Laura Neil Limited | Administrative & support | 2024 |
| Lawes Property Co. Ltd | Real estate | 2014 |
| Lawlor Interiors Limited | Professional & scientific | 2022 |
| Layers and Lines Spatial Design Ltd | Professional & scientific | 2025 |
| Layerv Holdings Limited | Financial services | 2017 |
| Layerv Ltd | Extraterritorial | 2013 |
| Layton Homewares Ltd | Wholesale & retail | 2026 |
| Lazr Trans Ltd | Other services | 2017 |
| LB Closing Ltd | Professional & scientific | 2024 |
| LB Culinary Ltd | Hospitality | 2023 |
| LBM Consulting Limited | Information & communication | 2003 |
| LBN Maidenhead Limited | Health & social care | 2018 |
| LBN Marlow Limited | Health & social care | 2025 |
| LBP Property Services Limited | Construction | 2022 |
| LCA Consultancy Services Ltd | Professional & scientific | 2022 |
| Lcbi London Limited | Wholesale & retail | 2026 |
| Lccd Limited | Construction | 2020 |
| LCL Design & Build Limited | Construction | 2017 |
| LDM Medical Services Limited | Health & social care | 2016 |
| LE Compound Ltd | Professional & scientific | 2026 |
| LE Firm Energy Ltd | Administrative & support | 2026 |
| LE Véritable Ltd | Extraterritorial | 2015 |
| Lead Designer Ltd | Construction | 2025 |
| Lead Revolution Ltd | Information & communication | 2024 |
| LEAD4PERFORMANCE Ltd | Professional & scientific | 2024 |
| Leadenhall Group Ltd | Real estate | 2018 |
| Leasehold Deed Aschbachring 68 D-66127 Saarbrucken Grundbuch Blatt 1009 Krughutte L.P. | | 2013 |
| LEE Dynasty Limited | Hospitality | 2024 |
| LEE Farnsworth & Associates Ltd | Professional & scientific | 2013 |
| LEE Mercer Consultancy Ltd | Information & communication | 2013 |
| Leemo Health Care Ltd | Health & social care | 2017 |
| Legacy Publishing Limited | Arts & recreation | 2024 |
| Legacy Reality Limited | Real estate | 2025 |
| Legal Buddy Limited | Professional & scientific | 2019 |
| Legendary Living Limited | Wholesale & retail | 2005 |
| Lehigh UK Limited | Financial services | 2000 |
| Lei-Lani Fitness CIC | Arts & recreation | 2024 |
| Leisure Inc ( Knightsbridge) Limited | Hospitality | 2006 |
| Lelong Limited | Other services | 2012 |
| Lemon PIG Limited | Administrative & support | 2025 |
| LEO Laboratories Limited | Wholesale & retail | 1960 |
| LEO Medica Europe Ltd | Manufacturing | 2016 |
| Leoline Travel Limited | Transport & logistics | 2018 |
| Leomina Productions Ltd | Information & communication | 2021 |
| Leonie Consulting Ltd | Professional & scientific | 2026 |
| Lerr Consulting Ltd | Administrative & support | 2021 |
| Less Annoying IT Ltd | Information & communication | 2015 |
| Let's Dive in! Limited | Education | 2017 |
| Levantine Eateries Limited | Hospitality | 2020 |
| Level 90 Bars Ltd | Hospitality | 2025 |
| Level Change Digital Ltd | Professional & scientific | 2022 |
| Levelled UP Limited | Other services | 2023 |
| Levertech Limited | Information & communication | 1987 |
| Leviathon Ltd | Professional & scientific | 2010 |
| Levive Services Ltd | Wholesale & retail | 2013 |
| Levolto Ltd | Wholesale & retail | 2024 |
| Lewin Construction Ltd | Construction | 2014 |
| LEX Detailing Ltd | Wholesale & retail | 2026 |
| LF Takeaway Ltd | Hospitality | 2022 |
| LGP Projects Ltd | Professional & scientific | 2025 |
| Lharwood Construction Limited | Manufacturing | 2022 |
| Liaison Chauffeurs Ltd | Transport & logistics | 2025 |
| Liberation Software Ltd. | Professional & scientific | 2000 |
| Liberty Polythene Limited | Administrative & support | 2025 |
| Liberty Rose Equestrian Ltd | Extraterritorial | 2015 |
| Licence Services Ltd | Real estate | 1970 |
| Lidsey Landfill Limited | Water & waste | 1988 |
| Life Treasury Limited | Other services | 2016 |
| Lifestyle Magazines Limited | Information & communication | 2012 |
| Lighthouse Canton UK PTE Ltd | Financial services | 2022 |