| K a Smart Solutions Ltd | Wholesale & retail | 2019 |
| K Mitchell Consulting Ltd | Professional & scientific | 2023 |
| K&S Franklin Estates Ltd | Real estate | 2025 |
| K&Y UK Cleaning Limited | Construction | 2019 |
| K-Elite Ltd | Administrative & support | 2024 |
| K-Tec Electrical London Ltd | Professional & scientific | 2021 |
| K.B. Group Limited | Real estate | 1996 |
| K9-UNIT.COM Ltd | Administrative & support | 2009 |
| K9DIAMONDS Ltd | Wholesale & retail | 2021 |
| KA Media Limited | Administrative & support | 2019 |
| Kaan Foods Ltd | Manufacturing | 2018 |
| Kale Ltd | Construction | 2020 |
| Kalex Cornwall Ltd | Hospitality | 2021 |
| Kalik Properties Ltd | Real estate | 2025 |
| Kalli's Catering Ltd | Hospitality | 2026 |
| KAM ASH Solicitors Ltd | Professional & scientific | 2026 |
| Kamox Limited | Administrative & support | 2023 |
| Kanita Label Limited | Wholesale & retail | 2023 |
| Kaplan Painting Services Ltd | Construction | 2020 |
| Karadag Food Ltd | Wholesale & retail | 2019 |
| Karadag Investments Ltd | Real estate | 2023 |
| Kari Smith Design Limited | Professional & scientific | 2017 |
| Karnya Limited | Agriculture & fishing | 2021 |
| Karpha Homes Limited | Real estate | 2025 |
| Kate Haus Ltd | Professional & scientific | 2020 |
| Kattidam Limited | Construction | 2020 |
| Kaur Events & Food Limited | Hospitality | 2023 |
| KAW Media Limited | Professional & scientific | 2025 |
| Kay's Auto Care Ltd | Wholesale & retail | 2013 |
| Kayman Services & Holdings Ltd | Construction | 2025 |
| Kayra Berkin Ltd | Other services | 2020 |
| KB 100 Ltd | Agriculture & fishing | 2019 |
| KB 101 Ltd | Professional & scientific | 2019 |
| KB Print Limited | Manufacturing | 2022 |
| KBH Building Services Limited | Construction | 2014 |
| KBH Haus Limited | Extraterritorial | 2023 |
| KBH London Limited | Extraterritorial | 2019 |
| Kblue Media Limited | Arts & recreation | 2019 |
| KBP Autos Limited | Wholesale & retail | 2025 |
| KC Consulting Group Ltd | Professional & scientific | 2022 |
| KCK Assets Limited | Real estate | 2024 |
| Kdem UK Ltd | Real estate | 2023 |
| KDL Roofing & Maintenance Ltd | Construction | 2026 |
| KEA Services Ltd | Hospitality | 2023 |
| Kebab Disco Ltd | Manufacturing | 2025 |
| KEM Repair Centre Ltd | Wholesale & retail | 2017 |
| Kemal Retail Limited | Wholesale & retail | 2017 |
| Kenda Events Ltd | Other services | 2022 |
| Kent Solutions & Management Ltd | Other services | 2010 |
| Kerem Properties Ltd | Real estate | 2024 |
| Kerr Parker Ltd | Professional & scientific | 2024 |
| Keser Ltd | Other services | 2019 |
| Kesh Communications Ltd | Professional & scientific | 2022 |
| Kevin Martin Building Services Limited | Construction | 2003 |
| Keye Management Limited | Real estate | 2018 |
| Keyframes Media Productions Ltd | Information & communication | 2016 |
| Keystone Capital Group Ltd | Financial services | 2025 |
| Keystone Search Ltd | Administrative & support | 2025 |
| Kiad Limited | Construction | 2013 |
| Kilbs Ltd | Construction | 2025 |
| Kilcoltrim Construction Ltd | Construction | 2017 |
| Kimyra Ltd | Other services | 2024 |
| Kinder Miles Group Ltd | Transport & logistics | 2025 |
| Kingdom Packaging Limited | Professional & scientific | 2017 |
| Kingdom Social Ltd | Hospitality | 2025 |
| Kingsbridge Global Trade Ltd | Transport & logistics | 2019 |
| Kingsdown Consulting Limited | Professional & scientific | 2017 |
| Kingsley Park (Billericay) Management Company Limited | Households | 2025 |
| Kingsmoor Group Limited | Households | 2021 |
| Kingswood Chase Dog Boarding Kennels Limited | Other services | 2024 |
| Kirkman and Jourdain Construction Limited | Construction | 2017 |
| Kirkman and Jourdain Trustee Limited | Financial services | 2025 |
| Kissa Living Limited | Manufacturing | 2025 |
| KKR Solar Limited | Education | 2012 |
| Klaudio Avdiaj Ltd | Transport & logistics | 2024 |
| Kluxdevelopments Ltd | Real estate | 2025 |
| KMG Consultancy Limited | Other services | 2009 |
| KMG Property Management Limited | Real estate | 2020 |
| KMK Healthcare Ltd | Public administration | 2020 |
| KMR Logistics London Limited | Wholesale & retail | 2023 |
| KN Sports Ltd | Education | 2024 |
| Knbb Electrical Limited | Construction | 2020 |
| Knightsbridge Hair Ltd | Other services | 2022 |
| Knyghts Limited | Other services | 2001 |
| Kockycare Ltd | Wholesale & retail | 2025 |
| Kokovee Limited | Wholesale & retail | 2017 |
| Kolev&Son UK Ltd | Construction | 2010 |
| Koltransport Ltd | Transport & logistics | 2020 |
| Koocachoo Limited | Other services | 2015 |
| Koray Partners Limited | Administrative & support | 2025 |
| Koruev Ltd | Transport & logistics | 2015 |
| KORUEV96 Ltd | Transport & logistics | 2025 |
| Kosi Kebab Limited | Hospitality | 2025 |
| Kouprianoff London Limited | Professional & scientific | 2012 |
| Koyunlu Limited | Real estate | 2018 |
| KP Telecom Ltd | Information & communication | 2022 |
| KPJ Consultants Limited | Administrative & support | 2017 |
| KPM Tyres Ltd | Wholesale & retail | 2025 |
| KRG Services Ltd | Construction | 2021 |
| Kriptopayments Ltd | Information & communication | 2025 |