| Kashif Innovations Ltd | Wholesale & retail | 2026 |
| Kathiawari Complex Ltd | Real estate | 2023 |
| Katja Alexandra Limited | Health & social care | 2021 |
| Kave Associates Limited | Administrative & support | 2001 |
| Kaviora Ltd | Wholesale & retail | 2026 |
| Kavorell Ltd | Wholesale & retail | 2026 |
| Kawani Group Ltd | Wholesale & retail | 2018 |
| Kayan Beauty Limited | Manufacturing | 2021 |
| Kayaonu Ltd | Hospitality | 2019 |
| Kaykem Ltd | Real estate | 2010 |
| KB Coaching & Consulting Ltd | Professional & scientific | 2022 |
| KB Luxe Holdings Ltd | Real estate | 2025 |
| KBS Global Education Ltd | Education | 2026 |
| KE01 Ltd | Information & communication | 2022 |
| KE05 Ltd | Information & communication | 2021 |
| KE07 Ltd | Information & communication | 2022 |
| Kearsley Repair Group Ltd | Manufacturing | 2025 |
| Kebab House Limited | Hospitality | 2017 |
| KEBAB03 Ltd | Hospitality | 2017 |
| Kechkay Holdings Limited | Real estate | 2020 |
| Kechkay Management Services Limited | Information & communication | 2004 |
| Keegan Brown Darts Ltd | Arts & recreation | 2014 |
| Keep Buying More Ltd | Wholesale & retail | 2022 |
| Keith Wilson Automotive Smart Solutions Limited | Manufacturing | 2004 |
| Kells Medics Limited | Health & social care | 2024 |
| Kelly Turkey Breeders Limited | Agriculture & fishing | 1979 |
| Keltar Limited | Wholesale & retail | 2010 |
| Keltonfield Limited | | 1974 |
| Kelvedon Clocks Limited | Wholesale & retail | 2003 |
| Kempharm Limited | Extraterritorial | 2007 |
| Kemsley Property Consultants Limited | Real estate | 2002 |
| Kemsley Whiteley & Ferris Limited | Administrative & support | 2001 |
| KEN LEE Trading Limited | Wholesale & retail | 2018 |
| Kency Care Ltd | Health & social care | 2023 |
| Kenley Care Homes Ltd | Construction | 2002 |
| Kenneth Elliott & Rowe Limited | Real estate | 1988 |
| Kenpad Limited | Administrative & support | 2006 |
| Kent Property Investments Limited | Real estate | 2004 |
| Kenyro Ltd | Information & communication | 2025 |
| Keppel Estates Ltd. | Real estate | 1996 |
| KER Secretaries Limited | Extraterritorial | 1994 |
| Kerr & Noble Limited | Wholesale & retail | 1975 |
| Kerstep Consultants Limited | Information & communication | 1997 |
| Kertino Ltd | Wholesale & retail | 2025 |
| Kerwood & Kerwood Ltd | Administrative & support | 1978 |
| Kesgelazeen Limited | Information & communication | 2025 |
| KET Investments Limited | Administrative & support | 2002 |
| Ketos Security Limited | Administrative & support | 2014 |
| Kevin Flook Consultancy Limited | Professional & scientific | 2014 |
| Kevnob Resources Ltd | Wholesale & retail | 2025 |
| Key Investments & Marketing Services Ltd | Financial services | 2024 |
| Key Tuition Brentwood LP | | 2014 |
| Key Tuition Derby LP | | 2025 |
| Keyeservices Limited | | 1986 |
| Keys & Comfort Ltd | Hospitality | 2025 |
| Keyskill Computers Limited | Wholesale & retail | 1996 |
| Keystone Wholesalers Ltd | Wholesale & retail | 2025 |
| Keyway Lock Services Limited | Administrative & support | 1996 |
| KG Services Ltd | Health & social care | 2023 |
| KGF Group of Companies Ltd | Wholesale & retail | 2025 |
| KH Global Resourcing Ltd | Administrative & support | 2024 |
| Khaba Global Limited | Wholesale & retail | 2025 |
| Khaista Ltd | Professional & scientific | 2022 |
| Khalid Suleiman Ltd | Health & social care | 2013 |
| Khan Tandoori Limited | Hospitality | 2002 |
| Khawaja Tech Spot Ltd | Information & communication | 2024 |
| Khaya Project Ltd | Health & social care | 2006 |
| Khmmad Innovate Ltd | Wholesale & retail | 2026 |
| Khursheed Property Limited | Real estate | 2021 |
| Kibrom Ltd | Information & communication | 2025 |
| Kich & Co Ltd | Wholesale & retail | 2025 |
| Kidley Properties Limited | Real estate | 2004 |
| Kidz Land Ltd | Education | 2005 |
| Kilkee Lodge Care Home Limited | Health & social care | 1996 |
| KIM Homes Ltd | Real estate | 2025 |
| Kimb Internet Trading Ltd | Wholesale & retail | 2024 |
| Kinergen Research & Development Ltd | Professional & scientific | 2001 |
| Kinetiq Partners Ltd | Administrative & support | 2026 |
| King of Kings Church | Other services | 2012 |
| King Street Bakery Limited | Manufacturing | 1964 |
| King's Flavour Ltd | Hospitality | 2023 |
| Kingdom Group (UK) Limited | Real estate | 1996 |
| Kings Boiler Hire Limited | Construction | 1973 |
| Kings Mortgages Limited | Financial services | 2004 |
| Kings Square Limited | Financial services | 2023 |
| Kings Vehicle Solutions Limited | Wholesale & retail | 2005 |
| Kingsridge Properties Limited | Construction | 1988 |
| Kipcress Limited | Real estate | 2001 |
| Kirkman and Jourdain Limited | Construction | 1983 |
| Kirkpatrick Place Limited | Households | 2023 |
| Kirkuki Limited | Administrative & support | 2009 |
| Kirkwood Consulting Limited | Administrative & support | 2009 |
| Kisan Labs Ltd | Information & communication | 2016 |
| Kismet Balti Ltd | Hospitality | 2022 |
| KIT Property Investments Ltd | Real estate | 1998 |
| Kita Health and Wellbeing Limited | Health & social care | 2025 |
| Kivora Traders Limited | Wholesale & retail | 2025 |
| KK Foods Ltd | Hospitality | 2018 |
| KL Property Holdings Limited | Real estate | 2018 |
| KLA U.K. Limited | Professional & scientific | 2024 |