| KP Sound Systems Limited | Wholesale & retail | 2022 |
| KPR Estates Ltd | Real estate | 2024 |
| Kress Building Limited | Construction | 2018 |
| Kross Media Ltd | Information & communication | 2019 |
| Kryptstar Ltd | Information & communication | 2020 |
| Ksys Ltd | Information & communication | 2012 |
| KT Consultancy Ltd | Health & social care | 2025 |
| KT Management Consulting Services Ltd | Professional & scientific | 2024 |
| Ktec Plumbing & Heating Ltd | Construction | 2025 |
| Ktma Ltd | Hospitality | 2026 |
| KTS Consultancy Services Limited | Information & communication | 2011 |
| Kudo Property Ltd | Real estate | 2020 |
| Kudumpam Ltd | Real estate | 2023 |
| Kugan Medicals UK Ltd | Health & social care | 2024 |
| Kulfi Cafe Ltd | Hospitality | 2025 |
| Kurti BDS Ltd | Construction | 2022 |
| Kvdd Anaesthetic Services Limited | Health & social care | 2016 |
| Kyungri 4 U Ltd | Professional & scientific | 2021 |
| L & D Home Developments Limited | Construction | 2012 |
| L & T Reddington Civil Engineers Ltd | Construction | 2013 |
| L&H Designs Limited | Wholesale & retail | 2008 |
| L.C Decorating Services Limited | Construction | 2025 |
| L.C. Consultancy Limited | Professional & scientific | 2003 |
| LA Bella Luna Ltd | Hospitality | 2014 |
| Laal's Services Ltd | Transport & logistics | 2021 |
| Lala Brothers Construction Ltd | Construction | 2020 |
| Land Craft Consultancy Ltd | Administrative & support | 2025 |
| Landstamp (Consulting) Limited | Construction | 2020 |
| Lask Property Limited | Real estate | 2024 |
| Laura G London Ltd | Manufacturing | 2026 |
| Lavender Housing Ltd | Real estate | 2021 |
| Law & Compliance Ltd | Administrative & support | 2011 |
| Lazy Suzan Home Ltd | Wholesale & retail | 2025 |
| LB Bakers Ltd | Wholesale & retail | 2021 |
| LB Property Creations Ltd | Real estate | 2023 |
| LB Wholesaling Ltd | Wholesale & retail | 2023 |
| LCY Trans Ltd | Transport & logistics | 2018 |
| Leadify XYZ Ltd | Administrative & support | 2025 |
| LEE Construction Consultancy Ltd | Administrative & support | 2023 |
| Legal Publications Limited | Professional & scientific | 2001 |
| Lenagera Ltd | Real estate | 2019 |
| Lets Letlondonproperties Ltd | Construction | 2026 |
| Liberty Close Management Company Limited | Households | 2008 |
| Liberty Woodland School Training Ltd | Education | 2021 |
| Life and Soul Medicine Ltd | Health & social care | 2019 |
| LIFE4CHANGE Limited | Health & social care | 2019 |
| LIFE4CHANGE Properties Limited | Real estate | 2026 |
| Lilac London Ltd | Wholesale & retail | 2025 |
| Lilium House Management Company Limited | Households | 2025 |
| Lindum Road Ltd | Real estate | 2022 |
| Linlin Consulting Ltd | Professional & scientific | 2021 |
| Little Forest Ltd | Information & communication | 2006 |
| Little Hummingbird Daycare Limited | Health & social care | 2015 |
| Live the Life Coaching Limited | Professional & scientific | 2023 |
| LIZ Driving School Limited | Education | 2018 |
| LIZ Homes Limited | Real estate | 2023 |
| LJ Cosmetics Ltd | Health & social care | 2018 |
| LJN Business Solutions Ltd | Information & communication | 2018 |
| LK Rachev Ltd | Transport & logistics | 2024 |
| LM Plastering & Decorating Ltd | Construction | 2026 |
| Lockpoint Consulting Ltd | Information & communication | 2023 |
| Loftus (Services) Limited | Professional & scientific | 2010 |
| London Alien Ltd | Wholesale & retail | 2019 |
| London Card Show Ltd | Administrative & support | 2021 |
| London Celeb Ltd | Wholesale & retail | 2019 |
| London Event Productions Limited | Administrative & support | 2015 |
| London External Cleaning Services Ltd | Administrative & support | 2023 |
| London Korean Hummingbirds Choir CIC | Arts & recreation | 2024 |
| London Psychologist Centre Ltd | Hospitality | 2023 |
| London Tech Specialists Limited | Water & waste | 2019 |
| Lorven Business Solutions Limited | Information & communication | 2011 |
| Losira Ltd | Wholesale & retail | 2026 |
| Lotto International Ltd | Professional & scientific | 2023 |
| Lotus Construction Ltd | Construction | 2022 |
| Lotus Health Solutions Ltd | Health & social care | 2023 |
| Louisa Lask Aesthetics&Beauty Academy Ltd | Wholesale & retail | 2024 |
| Louise Crowe Creative Ltd | Professional & scientific | 2024 |
| Love Sushi Cheam Limited | Manufacturing | 2025 |
| Love Tinto Ltd | Professional & scientific | 2013 |
| Lowton Property Ltd | Real estate | 2017 |
| LPS Consulting Limited | Professional & scientific | 2015 |
| Lrtl Services Ltd | Administrative & support | 2024 |
| LSC Laser and Skin Clinic Limited | Other services | 2019 |
| LTC (London) Ltd | Other services | 2015 |
| Lucas Car Wash Ltd | Wholesale & retail | 2022 |
| Lucia's Caffeland Ltd | Hospitality | 2024 |
| LUX Vestra Art Limited | Professional & scientific | 2020 |
| Luxes Collection Limited | Wholesale & retail | 2012 |
| Luxmi Real Estates Ltd | Real estate | 2024 |
| M&B Decorators Limited | Construction | 2024 |
| M&G Strip OUT Ltd | Water & waste | 2019 |
| M&H Building and Maintenance Ltd | Construction | 2019 |
| M&L Advisory Limited | Extraterritorial | 2024 |
| M. C. S. Lighting Ltd | Construction | 2013 |
| M.R. Refurbs Limited | Construction | 2012 |
| M4 Cost Consultancy Ltd | Professional & scientific | 2015 |
| M5MONEYPENNY Limited | Real estate | 2014 |
| Mace (Worcester Park) Limited | Real estate | 2014 |
| MAD About a Dog Ltd | Wholesale & retail | 2019 |
| MAD Consultant Ltd | Information & communication | 2018 |