| KP Business Development Ltd | Professional & scientific | 2023 |
| Kpjv Limited | Administrative & support | 2010 |
| KPM Decorating Ltd | Construction | 2019 |
| KPS Business Limited | Real estate | 2026 |
| KR15HNA IT Solutions Ltd | Information & communication | 2020 |
| Kresna Software Limited | Information & communication | 2015 |
| Kristal Care Limited | Health & social care | 1996 |
| Kristal South Limited | Health & social care | 2016 |
| Krya Ltd | Health & social care | 2023 |
| KSS Control Ltd | Information & communication | 2017 |
| Ktnt Composites Ltd | Professional & scientific | 2024 |
| Kupkop UK Ltd | Health & social care | 2020 |
| KW Media Ltd | Information & communication | 2022 |
| Kwis Technology Limited | Extraterritorial | 2003 |
| Kyco PUB Co Limited | Hospitality | 2023 |
| Kyraphysioclinic Limited | Health & social care | 2026 |
| Kyuka Energies Ltd | Energy | 2025 |
| L & N Protection Ltd | Financial services | 2023 |
| L & R Catering Limited | Hospitality | 2008 |
| L Turner Ltd | Professional & scientific | 2022 |
| L&S Extensions Limited | Construction | 2019 |
| L.Johnston Company Limited | Wholesale & retail | 2024 |
| L3HARRIS Communications Systems UK Limited | Manufacturing | 1921 |
| L3HARRIS Defence Investments Limited | Administrative & support | 2011 |
| L5ELECTRICAL Ltd | Construction | 2023 |
| LA Palombe Ltd | Hospitality | 2023 |
| LA Saporita Pizza Ltd. | Wholesale & retail | 2023 |
| Labcell Holdings Limited | Financial services | 2021 |
| Labcell Limited | Wholesale & retail | 1992 |
| Labcell Trading Limited | Professional & scientific | 2012 |
| Labmate Scientific Ltd | Manufacturing | 2018 |
| Labyrinth Consulting Ltd | Construction | 2016 |
| Lacuna & Co (Eco Solutions) Ltd. | Wholesale & retail | 2013 |
| Ladyko Ltd | Professional & scientific | 2017 |
| LAE Property Deals Ltd | Real estate | 2024 |
| Lamari IT Ltd | Professional & scientific | 2025 |
| Lana Painting & Decorating Ltd | Construction | 2023 |
| Landed Talent Ltd | Administrative & support | 2024 |
| Langcrown Court Management Company Limited | Households | 1988 |
| Language in Bloom Clinic Ltd. | Information & communication | 2018 |
| Lansdale Engineering Limited | Manufacturing | 1985 |
| Lansdale Holdings Limited | Professional & scientific | 2017 |
| Lantech Inc Limited | Information & communication | 2016 |
| Laulind Limited | Other services | 1995 |
| Laura Allen Ltd | Health & social care | 2022 |
| Laurens Tattoo Services Ltd | Other services | 2015 |
| LAW-7 Ltd | Professional & scientific | 2013 |
| Laxmi Property Ltd | Real estate | 2017 |
| LB Builders Limited | Construction | 2020 |
| LB Trans Ltd | Transport & logistics | 2018 |
| Lbsic Ltd | Professional & scientific | 2009 |
| LCO Marine Limited | Financial services | 2000 |
| LCO Non-Marine and Aviation Limited | Financial services | 2000 |
| LE Orange Fish Co Limited | Construction | 1997 |
| LEAD3D Ltd | Arts & recreation | 2017 |
| Leading Property Developments Ltd | Construction | 2023 |
| Leap Ahead Consulting Limited | Professional & scientific | 2010 |
| Learn TKD Taekwon-Do Ltd | Education | 2009 |
| Learnpro Efireservice Limited | Information & communication | 2015 |
| Leathers Scaffolding Ltd | Construction | 2022 |
| Leckey’S Cleaning Services Ltd | Administrative & support | 2019 |
| LED Displays and Signs Limited | Manufacturing | 2012 |
| LEE Jobson Design and Build Limited | Construction | 2018 |
| Leech Studio Ltd | Professional & scientific | 2013 |
| Legal Planning Solutions Ltd | Administrative & support | 2017 |
| Leighs Lets Ltd | Real estate | 2025 |
| Lemoine Limited | Wholesale & retail | 2010 |
| LEN Consulting Limited | Professional & scientific | 2025 |
| Lenovo Global Financial Services (UK) Limited | Financial services | 2025 |
| Lenovo Global Technology UK Limited | Information & communication | 2016 |
| Lenovo Technology (United Kingdom) Limited | Manufacturing | 2003 |
| Leon Group Ltd | Information & communication | 2023 |
| LES Freres Limited | Hospitality | 2017 |
| LES Montres DE Reed Limited | Wholesale & retail | 2024 |
| Level Equals Limited | Professional & scientific | 2021 |
| Lewla Properties Limited | Real estate | 2020 |
| LG Events & Entertainment Ltd | Information & communication | 2025 |
| LG Real State Limited | Real estate | 2023 |
| LH Automotive Limited | Wholesale & retail | 2015 |
| Liberty Accounts Limited | Information & communication | 2003 |
| Liberty Rise Holdings Ltd | Construction | 2025 |
| Libertyaces Distribution Ltd | Information & communication | 2017 |
| Libertyaces Ltd | Information & communication | 2017 |
| Lichtwelle Medical Consultancy Limited | Health & social care | 2014 |
| Life Care Management Services Limited | Health & social care | 2019 |
| Lighthouse Bespoke Healthcare Ltd | Administrative & support | 2015 |
| Lighthouse Point Limited | Professional & scientific | 2026 |
| Lila Properties Ltd | Real estate | 2023 |
| Liliana Simpson Limited | Other services | 2015 |
| Lime Grove Interiors Limited | Arts & recreation | 2023 |
| Lime Tree Property Buyers Limited | Real estate | 2018 |
| Lime Tree Serviced Accommodation Limited | Real estate | 2018 |
| Limited Edition Studios Ltd | Wholesale & retail | 2019 |
| Lince Salisbury (UK) Limited | Professional & scientific | 2022 |
| Lincoln House Computer Services Limited | Construction | 1960 |
| Line Consulting Limited | Professional & scientific | 2019 |
| Linea Home Designs Ltd | Construction | 2014 |
| Linear Home Improvements Limited | Administrative & support | 2021 |
| Lineout Media Ltd | Information & communication | 2013 |
| Lingfield House Management Company Limited | Administrative & support | 1996 |