| Kovai Limited | Information & communication | 2021 |
| Kovai Ventures Limited | Financial services | 2022 |
| Kp's Catalogue Ltd | Wholesale & retail | 2022 |
| KPT Construction Ltd | Construction | 2014 |
| KS & KH Complex Ltd | Real estate | 2025 |
| Kumo Studio Limited | Information & communication | 2013 |
| Kurtoglu Marketing Ltd | Professional & scientific | 2020 |
| Kwal Group Limited | Administrative & support | 2019 |
| KWT Group Ltd | Professional & scientific | 2014 |
| KWT Homes Limited | Hospitality | 2020 |
| KWT Professional Services Limited | Professional & scientific | 2014 |
| L & B Trading Limited | Other services | 2022 |
| L & J Transportation Ltd | Administrative & support | 2010 |
| L and G Lifts Limited | Construction | 2011 |
| L&C Creations Ltd | Manufacturing | 2023 |
| L4MBURNA Properties Ltd | Real estate | 2018 |
| LA Souxe Group Limited | Information & communication | 2019 |
| Ladds Invest Ltd | Real estate | 2024 |
| Lagom Jantelagen Limited | Financial services | 2025 |
| Lajavan Services Limited | Wholesale & retail | 2024 |
| Land of Goshen Limited | Education | 2015 |
| Langdale Access Limited | Construction | 2023 |
| Langdale Associates Limited | Construction | 2013 |
| Langdale Construction Limited | Construction | 2014 |
| Lanta Creative Limited | Administrative & support | 2006 |
| Laser Life Limited | Manufacturing | 2008 |
| Lasercut.London Ltd | Professional & scientific | 2023 |
| Latitude Supplements Ltd | Wholesale & retail | 2025 |
| Laver Group Services Limited | Administrative & support | 2024 |
| Lavertising Ltd | Professional & scientific | 2022 |
| LB Contractors Limited | Construction | 2010 |
| Lbsh (Hythe) Limited | Construction | 2014 |
| LC Jackson Limited | Manufacturing | 2013 |
| LCE Properties London Ltd | Real estate | 2024 |
| Lchvip Limited | Transport & logistics | 2024 |
| LD Trading Ltd | Wholesale & retail | 2017 |
| LDC Group Holdings Limited | Wholesale & retail | 2019 |
| LDN Bespoke Ltd | Construction | 2024 |
| LDN Waste Ltd | Water & waste | 2020 |
| LDR Plastering & Rendering Specialists Limited | Construction | 2024 |
| Leacon Road Holdings Limited | Construction | 2025 |
| Leaky Pipe Systems Limited | Manufacturing | 1990 |
| Learn French With Alexa Limited | Education | 2009 |
| Lefke BBQ Limited | Hospitality | 2015 |
| Legacy Construction Group Limited | Construction | 2021 |
| Legal Processing (UK) Limited | Administrative & support | 2011 |
| Lejuna Limited | Health & social care | 2019 |
| Leman Sixty Two Limited | Real estate | 2025 |
| Lera KAY Real Estate Ltd | Real estate | 2017 |
| LES Piton Ltd | Education | 2012 |
| Lets GET Ready to Crumble Ltd | Hospitality | 2022 |
| Lett's Care Ltd | Health & social care | 2013 |
| Level Architecture Ltd | Professional & scientific | 2011 |
| Level Homes (South East) Limited | Real estate | 2020 |
| Level Roofing and Building Contractors Limited | Construction | 2024 |
| Level Roofing Limited | Construction | 2023 |
| Levelup Property Management Limited | Professional & scientific | 2018 |
| LF GAS Services Limited | Construction | 2003 |
| Liberato Limited | Information & communication | 2013 |
| Liemur Limited | Information & communication | 2003 |
| Liftpro Technical Services Limited | Construction | 2020 |
| Lilalex International Legal Consulting Ltd | Professional & scientific | 2015 |
| Lindenwood Holdings Limited | Construction | 2020 |
| Linear Property Services Limited | Construction | 2016 |
| Ling Design Limited | Information & communication | 1998 |
| Link Last Mile Limited | Transport & logistics | 2026 |
| Link Plastics and Moulds Ltd | Manufacturing | 2017 |
| LINKS2U Limited | Information & communication | 2005 |
| Lion Flooring Limited | Construction | 2023 |
| Liquid Assets Consulting Limited | Professional & scientific | 2023 |
| Listic Limited | Construction | 2018 |
| Lite Space 2 Ltd | Manufacturing | 2016 |
| Little Dolphins Day Nursery Limited | Education | 2012 |
| Little Forest Pre-School Limited | Education | 2022 |
| Little Green Monkey Limited | Administrative & support | 2007 |
| Littleheath Management Limited | Real estate | 2007 |
| LLD Admin Limited | Administrative & support | 2018 |
| LMC Domestic Limited | Construction | 2019 |
| LNS Services Ltd | Construction | 2026 |
| Loaf & Co Holdings Ltd | Real estate | 2024 |
| London Chauffeur Travel Limited | Administrative & support | 2023 |
| London Facilities Management Ltd | Construction | 2022 |
| London Flooring Company Ltd. | Construction | 2012 |
| London Pure Essence Limited | Hospitality | 2025 |
| London’S Finest Drainage Ltd | Water & waste | 2020 |
| Lotties Barkery Ltd | Manufacturing | 2025 |
| Lotus Nail Group Limited | Other services | 2025 |
| Lotv Capital Ltd | Hospitality | 2025 |
| Lovebedrooms Limited | Administrative & support | 2014 |
| Lovedalecare Ltd | Administrative & support | 2022 |
| Lovely Lorna Ltd | Manufacturing | 2025 |
| Lows Design and Build Ltd | Construction | 2020 |
| Loxdon Group Limited | Construction | 2020 |
| Loxley Investment Management Limited | Professional & scientific | 2025 |
| Loxley Security Limited | Public administration | 2006 |
| LP Electrical and Building Limited | Construction | 2016 |
| Lray Joinery Ltd | Manufacturing | 2015 |
| LT Crafts Limited | Arts & recreation | 2025 |
| LTM Trading Ltd | Wholesale & retail | 2024 |
| Lucca Close Management Limited | Households | 2025 |