| Kristian Dench Limited | Information & communication | 2014 |
| Kristian Peel Architecture Ltd | Professional & scientific | 2024 |
| Kritrima Prajna (UK) Limited | Information & communication | 2024 |
| Kross Studio Ltd | Professional & scientific | 2018 |
| Kryger Limited | Professional & scientific | 2024 |
| Ksense Limited | Information & communication | 2012 |
| KSI Cosmetic Limited | Health & social care | 2018 |
| KT Dental Smiles Ltd | Health & social care | 2026 |
| Kumari Property Ltd | Real estate | 2022 |
| KXA Consulting Ltd | Professional & scientific | 2024 |
| L & K Partnership Limited | Professional & scientific | 2006 |
| L & S Garden Services Limited | Other services | 2014 |
| L and N Living Spaces Ltd | Administrative & support | 2019 |
| L Cristea Building Services Limited | Construction | 2022 |
| L&M Asset Management Ltd | Real estate | 2025 |
| L.E. Cramer Motor Engineers Limited | Wholesale & retail | 1965 |
| L.J.F. Marketing Service Ltd | Administrative & support | 1995 |
| L.P.L. Fitters Limited | Construction | 2006 |
| L.Philbin Commercial Properties Ltd | Real estate | 2026 |
| LA Reforma Ltd | Arts & recreation | 2025 |
| Laburnum Court (Ferring) Residents Association Limited | Real estate | 2000 |
| Lagolosa Ltd | Hospitality | 2023 |
| Laine Theatre Arts Holdings Limited | Financial services | 1997 |
| Laine Theatre Arts Limited | Education | 1974 |
| Lakeview Retreats Limited | Hospitality | 2023 |
| Lakman Property Investments Limited | Real estate | 2024 |
| Lambie Holdings Ltd | Real estate | 2021 |
| Lanbridge Limited | Extraterritorial | 2001 |
| Lance Estates Limited | Real estate | 2001 |
| Lanceplace Homes Limited | Real estate | 1988 |
| Landfall Ltd | Professional & scientific | 2022 |
| Landim (BEA Building) Limited | Construction | 2020 |
| Landim Limited | Construction | 2020 |
| Landon Garment Care Limited | Other services | 2008 |
| Landray Legal Ltd | Professional & scientific | 2019 |
| Landvest (Bucks) Limited | Construction | 2013 |
| Landvest Limited | Construction | 2010 |
| Landworth Electrical Engineering Limited | Construction | 2020 |
| Lang Hospitality Ltd | Hospitality | 2026 |
| Langham Property Services Ltd. | Real estate | 1995 |
| Laravita Ltd | Wholesale & retail | 2018 |
| Laren Consulting Limited | Professional & scientific | 2013 |
| Larkmill Limited | Administrative & support | 2008 |
| Latam Investor Ltd | Information & communication | 2013 |
| Latham Smith Ltd | Real estate | 2014 |
| Latimer Chase (Chorleywood) Management Company Limited | Households | 2013 |
| Launchbuild Limited | Households | 1985 |
| Launchpad Developments Ltd | Real estate | 2026 |
| Lauren Diventura (LDV) Consulting Ltd | Professional & scientific | 2024 |
| Laverbrook Ltd | Construction | 2021 |
| Lawden MC Ltd | Professional & scientific | 2017 |
| Laxstrat Ltd | Real estate | 2022 |
| LB Civil Solutions Ltd | Construction | 2026 |
| Lb.Av London Limited | Construction | 2013 |
| LB3 Consulting Limited | Information & communication | 2026 |
| LC Labs Ltd | Manufacturing | 2025 |
| LC Physiotherapy and Performance Ltd | Professional & scientific | 2025 |
| LCL 1867 Limited | Professional & scientific | 2023 |
| Leadership Performance Consulting Ltd | Professional & scientific | 2024 |
| Lean Think Ltd | Professional & scientific | 2025 |
| LED London Energy Limited | Construction | 2018 |
| LEE & Co Wealth Management Ltd | Financial services | 2026 |
| LEE Accounting Services Ltd | Real estate | 2001 |
| Lee's Trees Limited | Administrative & support | 2008 |
| Leers and LEE Investments Limited | Real estate | 2025 |
| Left Hand State Limited | Information & communication | 2017 |
| Legendary Properties Limited | Construction | 2009 |
| Legends Food Limited | Hospitality | 2017 |
| Lemniscate Limited | Real estate | 2004 |
| Lemongrass Grove Limited | Real estate | 2021 |
| Lendifi Ltd | Financial services | 2024 |
| Lesnet Investments Limited | Professional & scientific | 2018 |
| Lester Harrison Ltd | Real estate | 2003 |
| Lewen Studio Ltd | Wholesale & retail | 2026 |
| Lewis Construction Ltd | Construction | 2015 |
| Lewis Feeley Limited | Real estate | 2017 |
| Lewis O'Neill Properties Ltd | Real estate | 2019 |
| Leyla Veterinary Services Ltd | Professional & scientific | 2021 |
| LFK Limited | Real estate | 2005 |
| Liam O Carroll Professional Decorating Ltd | Construction | 2022 |
| LIB Group Ltd | Hospitality | 2026 |
| Libertas Brands Ltd | Professional & scientific | 2023 |
| Libertas IP Limited | Professional & scientific | 2025 |
| Libertas Ventures Ltd | Professional & scientific | 2023 |
| Lidia S Makeup Limited | Other services | 2020 |
| Life HR Ltd | Administrative & support | 2016 |
| Life Invest Property Limited | Real estate | 2024 |
| Lifelink Trading Limited | Wholesale & retail | 2017 |
| Lightwater Fryers Limited | Hospitality | 2010 |
| Like a Leaf on the Wind Limited | Information & communication | 2025 |
| Lily Vesta Limited | Real estate | 2020 |
| Lime HR Ltd | Administrative & support | 2011 |
| Lindsay East Limited | Administrative & support | 2013 |
| Linkology Inc Limited | Information & communication | 2021 |
| Linlen Property Investments Limited | Real estate | 2005 |
| Linosa Limited | Wholesale & retail | 1974 |
| Lion Developments Ltd | Real estate | 2017 |
| Liparus Limited | Professional & scientific | 2024 |
| Liquicount Ltd | Manufacturing | 2025 |
| Little Gastronomic Secrets UK Limited | Hospitality | 2017 |