| KSN Limited | Wholesale & retail | 2022 |
| Ksquared Property Limited | Real estate | 2024 |
| Kstec Group Ltd | Information & communication | 2016 |
| KTM Global Consulting Limited | Information & communication | 2006 |
| Kuanza Construction Ltd | Construction | 2013 |
| Kuber Dhaval Estates UK PVT Limited | Real estate | 2023 |
| Kuman Properties Ltd | Financial services | 2021 |
| Kumon Wembley Central Limited | Administrative & support | 2020 |
| Kushram Ltd | Wholesale & retail | 2010 |
| Kutub Limited | Wholesale & retail | 2022 |
| KVA Ltd | Real estate | 2018 |
| KVP Direct Ltd | Professional & scientific | 2025 |
| Kyejo Limited | Information & communication | 2024 |
| Kyella Limited | Health & social care | 2016 |
| Kyrene Limited | Administrative & support | 2022 |
| Kysk Drinks Ltd | Manufacturing | 2025 |
| Kz-Cubed Ltd | Real estate | 2023 |
| L & D Investments Limited | Real estate | 2019 |
| L & G Trading Ltd | Real estate | 2017 |
| L a Scenic Ltd | Construction | 2022 |
| L C Aesthetica Ltd | Other services | 2019 |
| L&T Property Services Limited | Other services | 2024 |
| L'Aquila Importers & Distributors Limited | Professional & scientific | 2003 |
| L-Star Ltd | Transport & logistics | 2014 |
| L.A. Aesthetics London Limited | Health & social care | 2025 |
| L.P.H.C.A. Limited | Other services | 1993 |
| LA Casa MIA Ltd | Real estate | 2024 |
| LA Nuit Limited | Wholesale & retail | 2023 |
| Labekka Limited | Information & communication | 2015 |
| Lablodge Limited | Real estate | 1985 |
| Lacunae Property Ltd | Real estate | 2014 |
| Laindon North Property Limited | Real estate | 2001 |
| Lakhmi Healthcare Limited | Health & social care | 2010 |
| Lalji & Co Ltd | Administrative & support | 2024 |
| Lamb Chiropractic Clinic Limited | Health & social care | 2009 |
| Lambar Software Limited | Information & communication | 2026 |
| Lambourn Investments Limited | Administrative & support | 2008 |
| Laming Hope Lettings Ltd | Real estate | 2022 |
| Laming Hope Residential Ltd | Real estate | 2014 |
| Lampco (UK) Limited | Wholesale & retail | 2000 |
| Lancaster House, Sussex Gardens Limited | Households | 1973 |
| Lancelot Management Freehold Limited | Real estate | 2020 |
| Landmark Immigration Ltd | Professional & scientific | 2023 |
| Landmark Lake Ltd | Real estate | 2019 |
| Lane Healthcare Limited | Health & social care | 2024 |
| Lanesra Capital Limited | Real estate | 2020 |
| Lanesra Champions Limited | Real estate | 2026 |
| Lanesra Holdings Limited | Real estate | 2020 |
| Lanesra International Limited | Real estate | 2026 |
| Lanesra Lodge Limited | Real estate | 2022 |
| Lanesra Plaistow Limited | Real estate | 2021 |
| Lanesra Quad Limited | Real estate | 2026 |
| Lanesra Romford Limited | Real estate | 2022 |
| Lanesra SL4 Limited | Real estate | 2021 |
| Langah Ltd | Real estate | 2010 |
| Langav Limited | Hospitality | 2009 |
| Langdi Limited | Wholesale & retail | 2023 |
| Langley Court Rest Home Limited | Health & social care | 1998 |
| Langside Consulting Ltd | Professional & scientific | 2025 |
| Lansdales Pharma Limited | Wholesale & retail | 2020 |
| Lapiz Europe Limited | Professional & scientific | 2006 |
| Lara Chamandi Ltd | Manufacturing | 2019 |
| Larange Limited | Wholesale & retail | 2025 |
| Larken Consultancy Ltd | Financial services | 2009 |
| Larkspur Edgware Development Limited | Construction | 2024 |
| Laryo Limited | Health & social care | 2026 |
| LAS Barbers Ltd | Other services | 2018 |
| Latimer Sales Ltd | Extraterritorial | 2017 |
| Lavin Landscape Ltd | Administrative & support | 2025 |
| Lavington Properties Limited | Real estate | 2024 |
| Lawrence Johns Limited | Professional & scientific | 2025 |
| Lawrence Rand Foundation CIC | Arts & recreation | 2026 |
| Laxmisai Ltd | Other services | 2016 |
| Layne Properties Limited | Real estate | 2020 |
| Lazarus Consulting Ltd | Professional & scientific | 2014 |
| LBT Holdings Limited | Hospitality | 2019 |
| LCG Beauty Secret Ltd | Wholesale & retail | 2020 |
| Lcsrt Ltd | Health & social care | 2021 |
| LCT Associates Ltd | Financial services | 2014 |
| Lcube Ltd | Transport & logistics | 2019 |
| LDB Music Ltd | Arts & recreation | 2009 |
| LDG92 Limited | Professional & scientific | 2024 |
| LE French Corner DM Ltd | Hospitality | 2023 |
| LE Pain Francais Limited | Manufacturing | 2019 |
| Leaning Tech Limited | Information & communication | 2024 |
| Leanvegan Limited | Hospitality | 2021 |
| Leap Gradient Limited | Information & communication | 2011 |
| Leapmart Limited | Real estate | 1982 |
| Learning Techniques Education Centre Ltd | Education | 2018 |
| Leatherhead Alley Limited | Real estate | 2023 |
| LEE Curling Golf Limited | Wholesale & retail | 2024 |
| Leela Group Ltd | Real estate | 2021 |
| Leena Properties Limited | Real estate | 2017 |
| Legacy Wood Crafters Ltd | Construction | 2024 |
| Legal Help NRI Ltd | Real estate | 2024 |
| Leicester Square Box Office Limited | Administrative & support | 2009 |
| Leicester Square Box Office Official Half Price Booth Limited | Professional & scientific | 2002 |
| Leicester Square Money Exchange Limited | Financial services | 2002 |
| Leigh Park Pharmacy Limited | Wholesale & retail | 2004 |
| Leisurefare Limited | Administrative & support | 2001 |