| Klosowski Family Holdings Ltd | Financial services | 2026 |
| KMA Construction Ltd | Construction | 2018 |
| KMS Investments Ltd | Professional & scientific | 2021 |
| Knight Crown Investments LE11 Ltd | Real estate | 2021 |
| Knight Crown Investments Ltd | Real estate | 2021 |
| Knight Financial Services Ltd | Financial services | 2017 |
| Knight Studio Ltd | Health & social care | 2003 |
| Knights ROW Commercial Finance Limited | Financial services | 2024 |
| Know-How Computer Systems Limited | Information & communication | 2000 |
| Knoxford Limited | Manufacturing | 2009 |
| KNP Property Ltd | Real estate | 2026 |
| KNP Services Ltd | Transport & logistics | 2023 |
| Koda Property & Investments Ltd | Real estate | 2020 |
| Kodiak Lettings Ltd | Real estate | 2023 |
| Kodiak Property Ltd | Real estate | 2022 |
| Kohn Construction Services Limited | Professional & scientific | 2007 |
| Konings College London Ltd | Education | 2022 |
| Kova Cafe Limited | Hospitality | 2026 |
| KP Exit Partners Ltd | Professional & scientific | 2026 |
| KPD Sales and Marketing Limited | Wholesale & retail | 2023 |
| KPM Scaffolding Limited | Construction | 2014 |
| Kprc Limited | Professional & scientific | 2011 |
| Kpsd Investments Limited | Financial services | 2020 |
| Kpudi Ltd | Other services | 2025 |
| Krafted by Khan Ltd | Manufacturing | 2022 |
| KRH Consulting Limited | Professional & scientific | 2022 |
| Kris Massage Therapist Ltd | Health & social care | 2023 |
| Kriss Morrison Cooper Independent Funeral Director Ltd | Other services | 2015 |
| Krns Properties Ltd | Real estate | 2008 |
| Krs-One Ltd | Transport & logistics | 2012 |
| Krusty Enterprises Ltd | Wholesale & retail | 2019 |
| KRV Enterprise Ltd | Wholesale & retail | 2026 |
| KS Property Services Ltd | Real estate | 2023 |
| Ksana Dynamics Ltd | Professional & scientific | 2021 |
| KSL Mouldtools Ltd. | Manufacturing | 2003 |
| Kssz Investments Limited | Financial services | 2019 |
| Kst's Limited | Wholesale & retail | 2008 |
| Ktiro Limited | Financial services | 2020 |
| KTM Living Ltd | Real estate | 2020 |
| Kullion Ltd | Wholesale & retail | 2025 |
| KVA Group Ltd | Wholesale & retail | 2024 |
| Kvic Investments Ltd | Real estate | 2026 |
| KWC Management Company Limited | Households | 2014 |
| Kwercky Ltd | Extraterritorial | 2014 |
| Kynexis Limited | Professional & scientific | 2026 |
| L a Logistics Limited | Transport & logistics | 2006 |
| L and R Roberts Renovations Ltd | Real estate | 2021 |
| L Cole Associates Limited | Financial services | 2019 |
| L J Deville Engineering Limited | Manufacturing | 2003 |
| L Pollard Plumbing Ltd | Construction | 2023 |
| L Reynolds Holdings Ltd | Construction | 1991 |
| L Walker Carpentry Limited | Manufacturing | 2022 |
| L&P Benson Limited | Financial services | 2012 |
| L&P Property Solutions Ltd | Real estate | 2025 |
| L'Marie Vita Ltd | Extraterritorial | 2022 |
| L-Bap Limited | Education | 2024 |
| L. Reynolds (Building Systems) Limited | Construction | 1963 |
| L.D Scott Fabrication Services Ltd | Manufacturing | 2013 |
| LA Chiquita Ltd | Hospitality | 2024 |
| Lace Fields Management Company Limited | Households | 2021 |
| Laceutics Limited | Professional & scientific | 2019 |
| LADHOLDING5 Ltd | Professional & scientific | 2026 |
| Ladkin Hosiery Limited | Manufacturing | 1976 |
| Ladybird IOT Ltd | Information & communication | 2024 |
| Lafayette Instruments Europe Ltd | Extraterritorial | 2006 |
| Laftern Limited | Administrative & support | 2008 |
| Lagom Strategy Ltd | Information & communication | 2014 |
| Lakeside Sporting Ltd | Wholesale & retail | 2026 |
| Lalc Limited | Other services | 2022 |
| Lallo Property Company Limited | Real estate | 2019 |
| Lanada Limited | Real estate | 2020 |
| Lancerfy Limited | Administrative & support | 2026 |
| Land Advisory Services Limited | Administrative & support | 2013 |
| Landcroft Project Partners Ltd | Professional & scientific | 2023 |
| Lander & Chohan Ltd | Hospitality | 2025 |
| Lander C Cooper Ltd | Administrative & support | 2007 |
| Landesign Planning and Landscape Limited | Professional & scientific | 2013 |
| Landmark C Limited | Real estate | 2025 |
| Landmark HJ Limited | Financial services | 2025 |
| Landmark Medicines Ltd | Manufacturing | 2022 |
| Landmark Vaccines Limited | Manufacturing | 2022 |
| Lang Conservation Ltd | Construction | 2019 |
| Langley Blinds Limited | Wholesale & retail | 2025 |
| Langley Interiors Limited | Wholesale & retail | 2025 |
| Lansdowne Allen Ltd | Construction | 2025 |
| Lanzarote Holiday Villas Limited | Hospitality | 2009 |
| Lapis TEK Ltd | Professional & scientific | 2025 |
| Larke Holdings Limited | Financial services | 2019 |
| Larke Property Holdings Limited | Real estate | 2025 |
| Laser and Light Ltd | Health & social care | 2011 |
| Latin Kitchen Limited | Hospitality | 2024 |
| Lauda Fabrications Limited | Manufacturing | 2006 |
| Laughing Buddha 3 Ltd | Hospitality | 2024 |
| Lauren Taylor Bespoke Limited | Manufacturing | 2017 |
| Lavatech Limited | Professional & scientific | 2013 |
| Lavender Psychotherapy Ltd | Administrative & support | 2009 |
| Lavenders of Covent Garden Limited | Extraterritorial | 2019 |
| Law Firm Solutions Limited | Professional & scientific | 2006 |
| Lawrence Worsley Limited | Financial services | 2018 |
| Lawyerism Ltd | Professional & scientific | 2023 |