| KOR Finance Ltd | Real estate | 2022 |
| Kororo Ltd | Real estate | 2024 |
| Korotkova Limited | Administrative & support | 2016 |
| Koru Creative Ltd | Professional & scientific | 2002 |
| Kotakov Ltd | Construction | 2020 |
| Koteli Ltd | Wholesale & retail | 2023 |
| Kovuri Systems Limited | Information & communication | 2021 |
| KP Plumbing Contracts Ltd | Construction | 2009 |
| Kpad Ltd | Administrative & support | 2014 |
| Kpbilagi Limited | Health & social care | 2007 |
| KPC House Limited | Real estate | 2014 |
| KPC Inventories Ltd | Real estate | 2018 |
| KPL Signs Limited | Construction | 2016 |
| KPS Property Management Services Ltd | Households | 2023 |
| Kpys Solutions Limited | Information & communication | 2025 |
| Krasimira 77 Ltd | Construction | 2018 |
| Krause Limited | Information & communication | 2022 |
| KRB Investments Limited | Real estate | 2022 |
| Krestcore 1 Ltd | Real estate | 2007 |
| Krestcore Ltd | Professional & scientific | 2007 |
| Krircvget Ltd | Construction | 2016 |
| Krishna Krupa Consulting Limited | Professional & scientific | 2011 |
| Krishna Unique Solutions Limited | Information & communication | 2016 |
| Krishnas Newsagents Limited | Wholesale & retail | 2006 |
| KRM Security Services Ltd | Administrative & support | 2018 |
| Krore Ltd | Real estate | 2014 |
| Krrashi Construction Ltd | Construction | 2019 |
| KS Building Services Engineering Limited | Administrative & support | 1997 |
| KS Consult Limited | Financial services | 2016 |
| KS Properties Barnet Ltd | Real estate | 2024 |
| KS.1 by Katie&Sukh Ltd | Wholesale & retail | 2023 |
| KS7 London Limited | Real estate | 2019 |
| KSG Technologies Limited | Information & communication | 2010 |
| Ksixteen Limited | Administrative & support | 2012 |
| KSM Real Estate Ltd | Real estate | 2023 |
| Ksmiracle Ltd | Information & communication | 2019 |
| Ksya Services Limited | Professional & scientific | 2021 |
| KT Coaching Ltd | Education | 2025 |
| KT Properties & Estate Ltd | Real estate | 2024 |
| KTC Limited | Professional & scientific | 2021 |
| KTM Access Limited | Administrative & support | 2016 |
| KTS Woodart Ltd | Manufacturing | 2018 |
| Kubera Assets Limited | Real estate | 2015 |
| Kubilay & Co Limited | Professional & scientific | 2010 |
| Kudarova Ltd | Wholesale & retail | 2023 |
| Kunalgalav Ltd | Information & communication | 2025 |
| Kurklu Properties Ltd | Real estate | 2025 |
| Kurt Food Limited | Wholesale & retail | 2022 |
| Kussan 2 Sisters Ltd | Hospitality | 2018 |
| KV Capital Management Limited | Financial services | 2026 |
| KV Design and Build Limited | Construction | 2014 |
| KVF Limited | Professional & scientific | 2013 |
| KVP Real Estate Ltd | Real estate | 2026 |
| KW Access Hire Limited | Administrative & support | 2024 |
| KW Edge Limited | Administrative & support | 2016 |
| Kyley Group Properties Ltd | Real estate | 2019 |
| Kyma Beauty Ltd | Manufacturing | 2026 |
| Kyrn International Trading Company Ltd | Wholesale & retail | 2016 |
| Kyroro Investments Ltd | Real estate | 2023 |
| KYY Trinity Fuel UK Ltd | Wholesale & retail | 2021 |
| L E Lettings Limited | Real estate | 2020 |
| L & J Leasing Ltd | Administrative & support | 2019 |
| L B D Investments Limited | Administrative & support | 2003 |
| L B D Maintenance Limited | Construction | 2005 |
| L Chopra Limited | Information & communication | 2021 |
| L Masters Limited | Administrative & support | 2010 |
| L Oliver Co Ltd | Arts & recreation | 2018 |
| L P Pallett Transport Limited | Transport & logistics | 2011 |
| L R Haulage Limited | Water & waste | 2018 |
| L SQ Ltd | Real estate | 2022 |
| L&A Plumbing and Heating Ltd | Construction | 2023 |
| L&B Consultancy Services Ltd | Financial services | 2023 |
| L&J PUB Co Limited | Hospitality | 2026 |
| L&R Residential Ltd | Real estate | 2019 |
| L&S Regional Ltd | Administrative & support | 2024 |
| L'Eglise Capital Limited | Financial services | 2022 |
| L'Exclusif Ltd | Wholesale & retail | 1988 |
| L'Or Aesthetics Face & Body Ltd | Other services | 2022 |
| L. a. Property Rentals Limited | Real estate | 2026 |
| L.B.W Plastering Ltd | Construction | 2020 |
| L.R.A. Motors Limited | Wholesale & retail | 2023 |
| LA Maison Investments Limited | Real estate | 2008 |
| LA Nails and Beauty Services Ltd | Other services | 2025 |
| LA369 Limited | Real estate | 2023 |
| LAB Thirteen Ltd | Administrative & support | 2025 |
| Labradevelopment Limited | Real estate | 2023 |
| Labradevelopments South Limited | Administrative & support | 2024 |
| Lack Ltd | Real estate | 2020 |
| Ladnor Estates Limited | Households | 2011 |
| Lady M (London) Limited | Administrative & support | 2017 |
| Laele Aesthetic Limited | Other services | 2022 |
| Laele Aesthetic London Limited | Other services | 2024 |
| Laguna Consultants Limited | Information & communication | 2014 |
| Lahari Limited | Real estate | 2020 |
| Lahari Solutions Limited | Information & communication | 2008 |
| Laibeth SET Build Ltd | Construction | 2025 |
| Lakeer Magazine CIC | Information & communication | 2025 |
| Lakeside Capital Limited | Hospitality | 2017 |
| Lakeside Classic Wines Ltd | Wholesale & retail | 2021 |
| Lakeside Media Ltd | Information & communication | 2024 |