| Kinobe Consulting Ltd | Professional & scientific | 2026 |
| Kinowa Co., Ltd. | Extraterritorial | 2015 |
| Kinston Supply Chain Limited | Wholesale & retail | 2026 |
| Kintelic Ltd | Professional & scientific | 2010 |
| Kintell Limited | Manufacturing | 2017 |
| Kinton Technology Limited | Information & communication | 1999 |
| Kinva BIO Ltd | Manufacturing | 2025 |
| Kiorutz Ltd | Manufacturing | 2025 |
| KIP Holdings Ltd | Manufacturing | 2017 |
| Kirazedip Ltd | Extraterritorial | 2025 |
| Kirby & West 2023 Limited | Hospitality | 2023 |
| Kirin 88 Ltd | Hospitality | 2025 |
| Kirin House Ltd | Hospitality | 2022 |
| Kirk Consulting Group Ltd | Professional & scientific | 2021 |
| Kirk Medcomms Limited | Professional & scientific | 2018 |
| Kirkby Court Management Company Limited | Households | 1991 |
| Kirly FS Ltd | Professional & scientific | 1995 |
| Kirly Group Holdings Ltd | Administrative & support | 2000 |
| Kirly Property Services Ltd | Real estate | 2010 |
| Kirly Trustees Ltd | Financial services | 1996 |
| Kirontech UK Holding Ltd | Financial services | 2019 |
| Kirontech UK Ltd | Information & communication | 2015 |
| Kirtonic Ltd | Information & communication | 2025 |
| Kismot Takeaway Ltd | Hospitality | 2022 |
| Kiss Communications Limited | Information & communication | 2007 |
| Kissane Health Limited | Other services | 2025 |
| Kistruck Limited | Real estate | 2025 |
| Kisuma Limited | Administrative & support | 2025 |
| KIT M&S Ltd | Manufacturing | 2025 |
| Kitai Pharmtrade International Limited | Extraterritorial | 2019 |
| Kitcat Analytics Limited | Professional & scientific | 2021 |
| Kitch-Bath Interiors Ltd | Wholesale & retail | 2017 |
| Kitchensmiths Limited | Construction | 2002 |
| Kition Research Limited | Professional & scientific | 2013 |
| Kiwi Auto Tuning Ltd. | Extraterritorial | 2020 |
| Kiwi Kitchencraft Limited | | 1991 |
| Kiwi Kāmura Ltd | Manufacturing | 2023 |
| Kizoot Limited | Education | 2016 |
| KJ Electrical Services & Renewables Ltd | Construction | 2026 |
| Kjay's Automotives Limited | Wholesale & retail | 2021 |
| KJL Motors Limited | Wholesale & retail | 2008 |
| Kjlc Ltd | Information & communication | 2025 |
| Kjstock Ltd | Wholesale & retail | 2024 |
| KK Cars Ltd | Transport & logistics | 2024 |
| KK Facilities Management Ltd | Administrative & support | 2026 |
| KK Innovations Limited | Financial services | 2020 |
| KK Stores Limited | Wholesale & retail | 2008 |
| Kladex Limited | Manufacturing | 2013 |
| Klar Consultancy Ltd | Professional & scientific | 2023 |
| Klein & Redwolf Ltd | Manufacturing | 2016 |
| Klein Anaesthetics (1) Ltd | Professional & scientific | 2016 |
| Klein Anaesthetics LLP | | 2016 |
| Kleine Wharf London (UK) Ltd | Real estate | 2022 |
| Klie Consultancy Limited | Real estate | 2020 |
| KLO X FIA Ltd | Wholesale & retail | 2023 |
| Kloek and Townley LGB Limited | Administrative & support | 2022 |
| Klosey Ltd | Wholesale & retail | 2026 |
| Kloud Consulting Limited | Professional & scientific | 2026 |
| Kloudy Limited | Wholesale & retail | 2015 |
| KLS Flooring Limited | Construction | 2002 |
| KM Miller Ltd | Health & social care | 2022 |
| Km-Rad Ltd | Health & social care | 2021 |
| KMC Planning Ltd | Transport & logistics | 2012 |
| KMC Transport Planning Ltd | Professional & scientific | 2022 |
| Kmdou Limited | Hospitality | 2022 |
| Kmgey Ltd | Financial services | 2023 |
| Kmgh Holdings Ltd | Real estate | 2020 |
| KMK Group UK Limited | Professional & scientific | 2022 |
| Kmkt Ltd | Construction | 2025 |
| Kmma Limited | Information & communication | 2016 |
| Kmnsgroup Limited | Construction | 2025 |
| Kneading Dough Ltd | Manufacturing | 2025 |
| Kneesworth Farms Ltd | Agriculture & fishing | 1999 |
| Knightley Carpentry & Building Ltd | Construction | 2009 |
| Knightly Ventures Limited | Professional & scientific | 2023 |
| Knights Aircraft Interiors Ltd | Manufacturing | 2018 |
| Knights END Financial Administration Limited | Financial services | 2014 |
| Knikks Solutions Limited | Health & social care | 2020 |
| KNOCK4 Ltd | Information & communication | 2011 |
| Knoetica Ltd | Education | 2019 |
| Knollect Ltd | Wholesale & retail | 2025 |
| Knotflix Ltd | Professional & scientific | 2023 |
| Knotty ASH Woodworking Limited | Manufacturing | 2002 |
| Knowledge Associates (Cambridge) Ltd | Professional & scientific | 2006 |
| Knowledge Associates International Ltd | Professional & scientific | 2015 |
| Knowledge Economy Developments Limited | Professional & scientific | 2001 |
| Knowledger Ltd | Information & communication | 2019 |
| Knowsis Limited | Information & communication | 2012 |
| Knox & Wren Ltd | Hospitality | 2025 |
| Knyx Ltd | Professional & scientific | 2025 |
| KO Hornchurch Ltd | Hospitality | 2025 |
| Ko.Di. Consultants Limited | Professional & scientific | 2016 |
| Koala & Tree Limited | Real estate | 2018 |
| Koala and Tree Living Limited | Real estate | 2019 |
| Koala and Tree Properties Limited | Real estate | 2021 |
| Kobalt Ukeig | | 2000 |
| Koch Foreign Trade Ltd | Wholesale & retail | 2023 |
| Kodiaq Technologies Limited | Manufacturing | 2023 |
| Koech Ngeny Limited | Health & social care | 2025 |
| KOG Audio Ltd | Wholesale & retail | 2014 |