| KG Premiere Ltd | Real estate | 2024 |
| Khawaja Properties Ltd | Real estate | 2025 |
| KIC Scaffolding Services Limited | Construction | 2019 |
| Kielder Surrey Ltd | Administrative & support | 2012 |
| KIM Landscaping and Demolition Ltd | Administrative & support | 2025 |
| Kim's Cuisine Ltd | Hospitality | 2019 |
| Kimchimama Ltd | Hospitality | 2021 |
| Kings Mead (98 Foley Road) Residents Management Limited | Households | 1989 |
| Kingsley House (Freehold) Company Limited | Households | 2002 |
| Kingston Motors Ltd | Wholesale & retail | 2019 |
| Kingston Rugby Football Club Limited | Arts & recreation | 1969 |
| Kinkell Limited | Administrative & support | 2013 |
| Kinno Ltd | Wholesale & retail | 2019 |
| Kitchen and Interior Solutions Ltd | Manufacturing | 2019 |
| Kithu Properties Ltd | Real estate | 2023 |
| KLR Wellbeing Limited | Other services | 2004 |
| KM Cleaning Masters Limited | Administrative & support | 2022 |
| KM Investment Holdings Ltd. | Real estate | 2015 |
| Knightsbridge Trading Limited | Wholesale & retail | 2021 |
| KNR PVT Ltd | Real estate | 2023 |
| KNS Fortunes Limited | Wholesale & retail | 2022 |
| KO Family Ltd | Hospitality | 2018 |
| Koey Property Limited | Real estate | 2020 |
| Koko Estates Ltd | Real estate | 2021 |
| Kore Studios Limited | Information & communication | 2003 |
| Korea House BBQ Ltd | Hospitality | 2020 |
| Korea House Ltd | Hospitality | 2013 |
| Korean Dish Ltd | Hospitality | 2025 |
| Kortx International Trading Limited | Wholesale & retail | 2017 |
| Koruma Limited | Wholesale & retail | 2012 |
| Kowiroch Holdings Limited | Wholesale & retail | 2019 |
| Kozzi Taste Ltd | Hospitality | 2016 |
| KR Consulting UK Ltd. | Education | 2002 |
| KS General Builders Ltd | Construction | 2015 |
| KS Partners Ltd | Hospitality | 2020 |
| KSP Carpentry & Building Solutions Ltd | Manufacturing | 2026 |
| KT10 Roofing Limited | Construction | 2022 |
| Kulam's Chippy Ltd | Hospitality | 2024 |
| KWP Build by Design Holdings Ltd | Real estate | 2017 |
| KWP Build by Design Ltd. | Construction | 2016 |
| Kymas & Co Ltd | Professional & scientific | 2024 |
| L and M Resources Limited | Hospitality | 2025 |
| L and S Properties International Ltd | Real estate | 2023 |
| L H Sign Solutions Ltd | Professional & scientific | 2014 |
| L-Base Ltd | Professional & scientific | 2018 |
| L.N Healthcare Services Limited | Health & social care | 2014 |
| LA 777 Ltd | Construction | 2020 |
| LA Coute Limited | Information & communication | 2008 |
| LA Rosh Events Limited | Other services | 2025 |
| Ladybird Media Limited | Professional & scientific | 2019 |
| LAL Flowers Limited | Hospitality | 2024 |
| Lambeth Scientific Services Limited | Other services | 1998 |
| Lang Court Freehold Company Limited | Households | 2021 |
| Langley Court Flat Management Company Limited | Real estate | 2001 |
| Lanka Books Limited | Wholesale & retail | 2024 |
| Laperostudios Ltd | Wholesale & retail | 2021 |
| LAS IT Support Ltd | Information & communication | 2018 |
| Lasn International Limited | Wholesale & retail | 2017 |
| Lazars Ltd | Transport & logistics | 2025 |
| LC Performance Coaching Ltd | Arts & recreation | 2022 |
| LDN Hire Ltd | Administrative & support | 2018 |
| Leader 804 Ltd | Wholesale & retail | 2025 |
| Leander Court (Surbiton) Residents Association Limited | Households | 1966 |
| Learn French Having FUN Ltd | Education | 2015 |
| Learn Play Achieve Academy Limited | Education | 2024 |
| Learnplayachieve Limited | Education | 2016 |
| Lebanese by Mezzet Ltd | Hospitality | 2016 |
| Legion of Vapers Ltd | Administrative & support | 2018 |
| Legion of Vaperz Ltd | Administrative & support | 2018 |
| Leighton House Maintenance Association Limited | Households | 1959 |
| Lemag Properties Limited | Real estate | 2021 |
| Leon Acikalin Golf Ltd | Arts & recreation | 2025 |
| Leonardo Becker Limited | Wholesale & retail | 2025 |
| Leosh Services Limited | Administrative & support | 2026 |
| Level UP Virtual Services Limited | Administrative & support | 2026 |
| Leybold UK Ltd | Manufacturing | 1960 |
| Lifestyle Creating Your Perfect Home Ltd | Construction | 2015 |
| Lima & J Limited | Construction | 2015 |
| Lime Orange Ltd | Hospitality | 2011 |
| Lindfors & Lindfors Limited | Professional & scientific | 2020 |
| Lindsay & Joe’S Ltd | Hospitality | 2025 |
| Lionways Leather Restoration Ltd | Manufacturing | 2026 |
| Literacy Lounge Limited | Education | 2013 |
| Little Echo Games Ltd | Information & communication | 2025 |
| Little Korea Ltd | Hospitality | 2022 |
| Little Peeps Play Ltd | Arts & recreation | 2024 |
| Little Peeps Soft Play Ltd | Arts & recreation | 2022 |
| LLS Security Protection Ltd | Administrative & support | 2025 |
| LMH Accountancy Solutions Ltd | Professional & scientific | 2022 |
| Lmqs Surveying Ltd | Professional & scientific | 2024 |
| Lodats Limited | Real estate | 2022 |
| London 10S Ltd | Hospitality | 2018 |
| London Antiques & Education Ltd | Wholesale & retail | 2009 |
| London Best Van Removals Ltd | Transport & logistics | 2022 |
| London Box Ltd | Wholesale & retail | 2018 |
| London Chelsea Property Group Limited | Real estate | 2024 |
| London City Football Academy Ltd | Education | 2025 |
| London Home Upgrades Ltd | Construction | 2014 |
| London Korean School Limited | Education | 2008 |
| London Music Radio Ltd | Information & communication | 2020 |