| Kingston University Enterprises Limited | Administrative & support | 1990 |
| Kingston University Service Company Limited | Real estate | 1995 |
| Kingston Upon Thames Chamber of Commerce | Other services | 1994 |
| Kingston Urology Ltd | Health & social care | 2025 |
| Kingston Veterinary Centre Ltd | Professional & scientific | 2016 |
| Kingston Women's Centre | Health & social care | 2011 |
| Kingstonfeet Ltd | Health & social care | 2020 |
| Kingswood Estates (S.E.) Limited | Real estate | 1987 |
| Kingswood Lane Management Limited | Households | 2022 |
| Kintrea Ltd | Professional & scientific | 2025 |
| Kire Consulting Ltd | Professional & scientific | 2022 |
| Kirkham (Trading) Limited | Manufacturing | 2004 |
| Kisby & Co Ltd | Professional & scientific | 2026 |
| Kiskidee Ltd | Professional & scientific | 2017 |
| Kiwi Megabyte Ltd | Information & communication | 2012 |
| KJ Family Limited | Wholesale & retail | 2025 |
| Kjaaad Construction Ltd | Construction | 2019 |
| Kjco Ltd | Information & communication | 2024 |
| KJV Construction Limited | Construction | 2006 |
| KK Investment Properties Limited | Real estate | 2018 |
| KK SERVICES4U Ltd | Construction | 2025 |
| KK SUB Limited | Hospitality | 2013 |
| Klass Reformer Ltd | Arts & recreation | 2025 |
| Kleneo Limited | Administrative & support | 2025 |
| KLI Consulting Limited | Professional & scientific | 2008 |
| Klokkit Ltd | Information & communication | 2026 |
| Kmdt IOI Ltd | Professional & scientific | 2026 |
| KMR Wellness Services Limited | Health & social care | 2017 |
| KMS (UK) Ltd | Real estate | 1998 |
| Knightingale Care Limited | Health & social care | 1999 |
| Knighton Industries Limited | Professional & scientific | 2001 |
| Knights Park Consultancy Limited | Professional & scientific | 2022 |
| Knowledge Garden Ltd | Information & communication | 2017 |
| Knox Financial Limited | Professional & scientific | 2009 |
| Koall Infrastructure Development Services (SSA) Limited | Professional & scientific | 2014 |
| Koete Ltd | Real estate | 2019 |
| Kohila Ltd | Construction | 2023 |
| Kokoro Business Services Limited | Professional & scientific | 2023 |
| Kokoro Networks Limited | Hospitality | 2020 |
| Komate Limited | Administrative & support | 2020 |
| Komoo Food Ltd | Wholesale & retail | 2021 |
| Koncept Medical Clinic Limited | Health & social care | 2020 |
| Konseption Limited | Information & communication | 2018 |
| Konseption Properties LLP | | 2019 |
| Korean Business Communications Limited | Administrative & support | 1993 |
| Korongo Ltd | Health & social care | 2022 |
| Korova Limited | Professional & scientific | 2001 |
| Kota Ltd | Other services | 2023 |
| Koum Network | Education | 2011 |
| Kovalcik Properties Limited | Real estate | 2023 |
| KPE Group Limited | Real estate | 2023 |
| KPE1 Limited | Real estate | 2023 |
| KPE2 Limited | Real estate | 2023 |
| KPE3 Limited | Real estate | 2023 |
| KQ Marketing Limited | Administrative & support | 2013 |
| Kragle Ltd | Financial services | 2026 |
| Krastev Design Ltd | Construction | 2016 |
| Kratis UK Ltd | Professional & scientific | 2025 |
| Krav Ltd | Real estate | 2022 |
| Kris Hermansson Ltd | Information & communication | 2026 |
| Kristen Dwyer Consulting Limited | Health & social care | 2015 |
| Kruger-Brent Consulting Limited | Administrative & support | 2009 |
| Kruz International Limited | Wholesale & retail | 2002 |
| Kspec Limited | Professional & scientific | 2016 |
| KT Autohaus Ltd | Wholesale & retail | 2025 |
| KT Construction Services Limited | Construction | 2026 |
| KT Entertainments Limited | Arts & recreation | 2006 |
| KT UK Property Ltd | Real estate | 2022 |
| KT1 Operations Limited | Real estate | 2026 |
| KU Holding Limited | Education | 2020 |
| KU Student Living Limited | Education | 2020 |
| Kudos London Limited | Construction | 2023 |
| Kuhlmeier Limited | Professional & scientific | 2012 |
| Kukumarche Ltd | Wholesale & retail | 2025 |
| Kula Studio Kingston Ltd | Health & social care | 2026 |
| Kultivate Consulting Limited | Arts & recreation | 2018 |
| Kultivate Properties Limited | Real estate | 2019 |
| Kumbh Capital Insights Ltd | Financial services | 2020 |
| Kummerc Group Ltd | Wholesale & retail | 2020 |
| Kuona Limited | Professional & scientific | 2011 |
| Kusp Marketing Limited | Professional & scientific | 2013 |
| Kuzey Yildizi Limited | Wholesale & retail | 2025 |
| KVM Transport Ltd | Transport & logistics | 2020 |
| KW Brokers Ltd | Financial services | 2026 |
| KY Lettings Limited | Real estate | 2005 |
| Kyriacou Ltd | Professional & scientific | 2021 |
| Kyse Ltd | Hospitality | 2022 |
| L & D Retail Limited | Wholesale & retail | 2002 |
| L & K Co. Ltd | Administrative & support | 2010 |
| L Media Corporate Limited | Other services | 2018 |
| L.A. Incorporated Ltd | Real estate | 2018 |
| L.E Shaw Limited | Information & communication | 2024 |
| L.O.C. Manufacturing Limited | Health & social care | 2005 |
| LA BON POM Ltd | Wholesale & retail | 2026 |
| LA Bottega (Teddington) Limited | Wholesale & retail | 2010 |
| LA Bottega DI ADA Ltd | Wholesale & retail | 2024 |
| LA Musa Design Studio Ltd | Professional & scientific | 2022 |
| Labdriver Limited | Information & communication | 2010 |
| Labyrinth Games Limited | Manufacturing | 2013 |
| Ladymere Place Residents Management Company Limited | Real estate | 1996 |