| Kingsford KEW and Linke Ltd | Financial services | 2023 |
| Kingsgrave Publishing Company Limited | Information & communication | 2024 |
| Kingshouse Group Limited | Professional & scientific | 1982 |
| Kingswood Court (Richmond) Limited | Real estate | 1989 |
| Kinshuck Family Dentistry Limited | Health & social care | 2008 |
| Kiplin Hall Trading CIC | Hospitality | 2013 |
| Kipper Box Limited | Real estate | 2014 |
| Kirsty's RAW & Pet Services Limited | Hospitality | 2022 |
| Kiss the Moon Limited | Manufacturing | 2013 |
| Kitchen LA Frenais Morgan LLP | | 2003 |
| Kitson and Sons Limited | Financial services | 2015 |
| Kiwi MCF Ltd | Professional & scientific | 2019 |
| KJT Technologies Limited | Energy | 2025 |
| KK Hadrian Ltd | Real estate | 2022 |
| KKB TM Ltd | Transport & logistics | 2020 |
| Klappe Design Ltd | Manufacturing | 2023 |
| Klasstin Ltd | Transport & logistics | 2025 |
| KM Real Estate Investments Ltd | Real estate | 2022 |
| KML Healthcare Ltd | Health & social care | 2022 |
| KMT Hansa Corp Limited | Professional & scientific | 2021 |
| Kmun Ltd | Administrative & support | 2025 |
| Kneeton Limited | Construction | 2000 |
| Knight Associates Ltd | Administrative & support | 2008 |
| Knightsbridge Court Management Company Limited | Households | 1977 |
| Knightsbridge Orthodontics Ltd | Health & social care | 2018 |
| Knightsgate Housing Ltd | Hospitality | 2018 |
| Knightsgate Properties Ltd | Real estate | 2016 |
| Knit With ME Limited | Wholesale & retail | 2023 |
| Knit-Id Limited | Other services | 2021 |
| Knock Through Ltd | Construction | 2015 |
| Knüg Limited | Wholesale & retail | 2019 |
| Kognix Ltd | Education | 2025 |
| Kome Food Ltd | Manufacturing | 2026 |
| Konecta Park Limited | Information & communication | 2024 |
| Konoa Limited | Transport & logistics | 2020 |
| Kouts Limited | Information & communication | 2007 |
| KR Van DEN Oever Ltd | Professional & scientific | 2023 |
| Kress Cooper Academy Ltd | Education | 2024 |
| Kress Cooper Elearning System (Kcels) Ltd | Education | 2020 |
| Kress Cooper Ltd | Professional & scientific | 2018 |
| Krishn Enterprise Limited | Wholesale & retail | 2015 |
| Krozen Design and Consultancy Ltd | Professional & scientific | 2018 |
| Kruidberg Private Equity Limited | Financial services | 2024 |
| Kruidberg Residential Limited | Construction | 2025 |
| KRW MSK Health Ltd | Health & social care | 2025 |
| Krwog Ltd | Health & social care | 2025 |
| KST Distribution Ltd | Wholesale & retail | 2022 |
| KTC Consulting Limited | Information & communication | 2025 |
| Kultura Litera Limited | Professional & scientific | 2020 |
| Kulwin Limited | Construction | 1993 |
| Kumano Limited | Information & communication | 2023 |
| Kumar Property Limited | Real estate | 2017 |
| Kumon Maidenhead, Braywick Study Centre LLP | | 2024 |
| Kureo Ltd | Professional & scientific | 2007 |
| Kuvid Consultants Ltd | Information & communication | 2016 |
| KXZ Group Ltd. | Wholesale & retail | 2018 |
| Kybele Films Ltd | Information & communication | 2026 |
| Kyle & Fisher Ltd | Wholesale & retail | 2026 |
| Kymata Hair Spa Limited | Other services | 2017 |
| KZ Services Limited | Professional & scientific | 2015 |
| L & P Management Services Ltd | Households | 2024 |
| L & R Lawn Care Services Ltd | Administrative & support | 2020 |
| L J F Lettings & Property Management Ltd | Real estate | 2020 |
| L M Galczynski Consulting Ltd | Financial services | 2011 |
| L&A Black Ltd | Professional & scientific | 2010 |
| L&S of Richmond Limited | Administrative & support | 2023 |
| L'Arte Della Pizza Limited | Hospitality | 2017 |
| L'Ecole DES Petits Limited | Education | 1991 |
| L'Orchidee DES Papillons Limited | Other services | 2015 |
| L. Markides Consulting Limited | Administrative & support | 2005 |
| LA Cocina North Yorkshire Limited | Hospitality | 2024 |
| LA Cocina Richmond Limited | Hospitality | 2026 |
| LA Luna DI Luca Ltd | Hospitality | 2026 |
| LA PAZ Property Limited | Real estate | 2014 |
| LA Petite Creperie UK Ltd | Hospitality | 2025 |
| LA Piazza Darlington Ltd | Hospitality | 2026 |
| LA Piazza Richmond North Yorks Ltd | Hospitality | 2015 |
| Laark Ltd | Manufacturing | 2008 |
| LAB Store Ltd | Wholesale & retail | 2025 |
| Labe Trade Ltd | Wholesale & retail | 2023 |
| Labscape Ltd | Information & communication | 2008 |
| Lagoon Developments Limited | Real estate | 1998 |
| Laima International Training Ltd | Manufacturing | 2019 |
| Lakewater Properties Limited | Construction | 2006 |
| Lamacraft and Co Ltd | Wholesale & retail | 2020 |
| Lamba Welding Systems Limited | Manufacturing | 1999 |
| Lambe & Co Limited | Professional & scientific | 2013 |
| Lambe Consultants Ltd | Professional & scientific | 2022 |
| Lambourn Commercial Ltd | Real estate | 2012 |
| Lan-Bridge Communications Ltd | Professional & scientific | 2012 |
| Lancaster Commodities Limited | Financial services | 2015 |
| Lancelot Properties (Holdings) Ltd | Financial services | 2025 |
| Lancelot Properties Limited | Construction | 1985 |
| Land Design Studio Limited | Arts & recreation | 1993 |
| Land Drainage Machinery Limited | Administrative & support | 2013 |
| Land Law Solutions Ltd | Professional & scientific | 2020 |
| Land Research Unit Limited | Information & communication | 1991 |
| Landchance Property Management Limited | Households | 1996 |
| Landing Properties Limited | Real estate | 2015 |
| Landsmart Landscapes Ltd | Administrative & support | 2017 |