| Korr Construction Limited | Construction | 2014 |
| Korr Group Limited | Financial services | 2025 |
| Korr Property Limited | Real estate | 2021 |
| Kraftgurus Limited | Wholesale & retail | 2020 |
| Kratos Advisory Ltd | Professional & scientific | 2026 |
| Kruger Logistics Limited | Transport & logistics | 2003 |
| Krupa (Indigo 3567) Ltd | Real estate | 2025 |
| Krupa (Indigo Mews) Ltd | Real estate | 2023 |
| Krupa (Parkhurst Mews) Ltd | Construction | 2022 |
| Krupa (Wakeling ST) Limited | Administrative & support | 2021 |
| Krupa Group Limited | Financial services | 2022 |
| Krupa Holdings Limited | Construction | 2019 |
| KSJ Food and Wine Ltd | Wholesale & retail | 2019 |
| KSS IV Logistics Ltd | Construction | 2023 |
| Kuickwheel UK Limited | Wholesale & retail | 2020 |
| KW Division Limited | Other services | 2018 |
| Kwasver Ltd | Professional & scientific | 2023 |
| Kylec Limited | Construction | 2018 |
| Kyma Consult Ltd | Professional & scientific | 2025 |
| L & R Limitless Renovations Partners Ltd | Real estate | 2023 |
| L K Consultants Limited | Administrative & support | 2013 |
| L Spencer Property Limited | Real estate | 2025 |
| L T Heating & Plumbing Services Ltd | Construction | 2017 |
| L&M Capital Holdings Ltd | Other services | 2018 |
| LA Churreria Ltd | Wholesale & retail | 2016 |
| Laculle Family & Partners Limited | Hospitality | 2014 |
| Ladybird Nurseries Chalfont Ltd | Education | 2024 |
| Ladybird Nurseries Limited | Education | 2017 |
| Ladybird Nurseries London Limited | Education | 2016 |
| Ladybirds (1991) Ltd | Transport & logistics | 2013 |
| LAH Events Ltd | Administrative & support | 2025 |
| Lambranzi Investment Group Limited | Financial services | 2024 |
| Lancer Enterprise Ltd | Hospitality | 2026 |
| Lancon Developments Ltd | Construction | 2023 |
| Landmark Communications Limited | Professional & scientific | 2021 |
| Landsecure Ltd | Construction | 2023 |
| Langley Invest LLP | | 2005 |
| Lanniston Developments Limited | Real estate | 2014 |
| Latchford Decorating Ltd | Construction | 2022 |
| Laurawhelan Ltd | Construction | 2025 |
| Lavender Park Golf Limited | Arts & recreation | 1975 |
| Lavish Design Ltd | Administrative & support | 2010 |
| Law for Schools CIC | Education | 2023 |
| Lcfclubs Bromley Ltd | Education | 2023 |
| LCH Advisory Ltd | Professional & scientific | 2023 |
| LEGACY123 Limited | Professional & scientific | 2017 |
| Legal Peace Ltd | Professional & scientific | 2022 |
| Lemon and Lime Associates Limited | Professional & scientific | 2021 |
| Leonway Ltd | Construction | 2018 |
| Lestir Investments Limited | Financial services | 2023 |
| Lestir Limited | Other services | 2022 |
| LESTIR23 Limited | Administrative & support | 2023 |
| Lets Play Netball Limited | Arts & recreation | 2010 |
| Lewis School Routes Ltd | Transport & logistics | 2025 |
| Lexington House Limited | Real estate | 2023 |
| Libertad Group Ltd | Financial services | 2024 |
| Life LAB Movement Limited | Arts & recreation | 2016 |
| Life LAB Sports and Fitness Limited | Arts & recreation | 2018 |
| Life of Productions Ltd | Information & communication | 2007 |
| Lifelong Solutions Limited | Financial services | 2009 |
| LIG PE Investments Limited | Professional & scientific | 2022 |
| Liike Limited | Information & communication | 2018 |
| Lili Holdings Ltd | Financial services | 2026 |
| Lili Property Ltd | Real estate | 2018 |
| Limac Properties Limited | Real estate | 2018 |
| Limbs 4 Africa Group UK Ltd | Health & social care | 2024 |
| Limehouse Construction Commercial Management Ltd. | Professional & scientific | 2015 |
| Limehouse Property Investments Ltd | Real estate | 2017 |
| Limitless Group Limited | Other services | 2019 |
| Linden Oak Properties Limited | Real estate | 2016 |
| Lindsay O'Neill Ltd | Wholesale & retail | 2018 |
| Lionsgate Equity Ltd | Financial services | 2025 |
| Liquidlabs Ltd | Information & communication | 2024 |
| Little Blue Research Ltd | Information & communication | 2016 |
| Live Beautifully Limited | Information & communication | 2018 |
| Live the Magic Limited | Arts & recreation | 2016 |
| Livewell 42 Limited | Arts & recreation | 2023 |
| LJF Property Ltd | Real estate | 2019 |
| Llazard Tech Ltd | Manufacturing | 2017 |
| Llucar Ltd | Other services | 2025 |
| Locallygood Express Ltd | Wholesale & retail | 2019 |
| Logica Cloud Limited | Information & communication | 2011 |
| Logs Hill Management Limited | Households | 1965 |
| Logs Hill Properties Limited | Real estate | 2021 |
| Lollipop Events Ltd | Hospitality | 1999 |
| Lombardy Associates Ltd | Professional & scientific | 2026 |
| London Festival Singers Ltd | Wholesale & retail | 2018 |
| London Mech Services Limited | Construction | 2015 |
| London Sivan Natpani Mantram Ltd | Education | 2020 |
| London Solar Group Ltd | Energy | 2026 |
| London Street Photo Festival C.I.C. | Professional & scientific | 2026 |
| Londonwide Cleaning Services Limited | Administrative & support | 1991 |
| Long Property Holdings Limited | Real estate | 2015 |
| Longtall Solutions Ltd | Information & communication | 2014 |
| Lonsur Ltd | Other services | 2026 |
| Lords of the Woods Ltd | Manufacturing | 2022 |
| Lottie Murphy Pilates Ltd | Other services | 2021 |
| Loupit Holdings Limited | Other services | 2026 |
| Love Walk | Health & social care | 1922 |
| Lovele Nails & Beauty Ltd | Other services | 2023 |