| Kingrose Limited | Financial services | 1992 |
| Kings Vine Christian Ministries | Other services | 2006 |
| Kingsbury Mobile Tyres Ltd | Wholesale & retail | 2025 |
| Kinn Consulting Ltd | Information & communication | 2025 |
| Kinng of Pizza (Watford) Ltd | Hospitality | 2026 |
| Kinng of Pizza Ltd | Hospitality | 2023 |
| Kinnor Limited | Financial services | 2024 |
| Kinspiration CIC | Education | 2023 |
| Kinsvera Limited | Wholesale & retail | 2026 |
| Kintora Ltd | Hospitality | 2025 |
| KIR Group Limited | Financial services | 2021 |
| KIR Spring Limited | Real estate | 2021 |
| KIR Venture Limited | Real estate | 2021 |
| Kiri Construction Ltd | Construction | 2022 |
| Kirit & Sons Ltd | Wholesale & retail | 2025 |
| Kirros Consulting Ltd | Professional & scientific | 2012 |
| Kite Finance Limited | Professional & scientific | 2019 |
| Kite Investco Limited | Real estate | 2025 |
| Kite Propco Limited | Real estate | 2020 |
| Kiyana Properties Limited | Real estate | 2025 |
| KJG Healthcare Limited | Health & social care | 2013 |
| KJS Building Solutions Limited | Construction | 2014 |
| KK Building Projects Ltd | Construction | 2012 |
| KKD Construction Ltd | Construction | 2021 |
| Kkiss Desserts Ltd | Hospitality | 2022 |
| KKO Property Group Ltd | Real estate | 2022 |
| KKP Contracts Ltd | Real estate | 2017 |
| KKR Consulting Limited | Professional & scientific | 2024 |
| KKR DRY Cleaning Limited | Other services | 2023 |
| Kkys Tech Ltd | Other services | 2023 |
| KL Fast Food Ltd | Hospitality | 2025 |
| Klass Tempo Logistics Ltd | Transport & logistics | 2025 |
| Kledi Ltd | Construction | 2014 |
| Klej Ltd | Health & social care | 2012 |
| KLK Estates Limited | Real estate | 2022 |
| KLR Global Ltd | Hospitality | 2024 |
| KLR Investment Holdings Limited | Financial services | 2019 |
| KLT Legal Services Ltd | Professional & scientific | 2023 |
| Klungsuwan Cuisine Ltd | Hospitality | 2023 |
| KM Building Specialists Ltd | Construction | 2016 |
| KM Contractors Ltd | Construction | 2021 |
| Km/Sm Ltd | Professional & scientific | 2022 |
| KMS Assest Management Ltd | Real estate | 2025 |
| Kmtt Limited | Professional & scientific | 2024 |
| KN Associates Ltd | Financial services | 2001 |
| Knai Ltd | Other services | 2024 |
| Knightsbridge Florist Ltd | Wholesale & retail | 2018 |
| KNM Developments Limited | Construction | 2020 |
| Knockmealdown Limited | Professional & scientific | 2003 |
| KNP Ventures Limited | Wholesale & retail | 2024 |
| KO Property Group Ltd | Real estate | 2025 |
| Koanaa Healthcare Limited | Professional & scientific | 2014 |
| Kodi Developments Ltd | Construction | 2022 |
| Kodi Group Ltd | Financial services | 2022 |
| Kodi Properties Ltd | Real estate | 2012 |
| Kodi Serviced Lets Ltd | Real estate | 2023 |
| Kojac Fashion Accessories UK Limited | Administrative & support | 1985 |
| KOL Ya'Akov Edgware Trust | Health & social care | 2022 |
| Kollel Beis Aharon (2013) Ltd | Education | 2013 |
| Kollel Beis Aharon Limited | Education | 2022 |
| Konata Properties (U.K.) Limited | Real estate | 1986 |
| Kondinave UK Limited | Transport & logistics | 2019 |
| Konnected Space Ltd | Information & communication | 2021 |
| Konsultant KEN Ltd | Real estate | 2021 |
| KOP Investments Limited | Financial services | 2009 |
| Korab Ltd | Construction | 2021 |
| Kordec Limited | Health & social care | 2013 |
| Kore Developments Ltd | Real estate | 2017 |
| Korozo UK Limited | Administrative & support | 2004 |
| Koschuta Ltd | Information & communication | 2022 |
| Kosher Edge Extra Limited | Other services | 2020 |
| Kosher Edge Limited | Other services | 2020 |
| Kosher Meat Centre Limited | Wholesale & retail | 2011 |
| Kosher Pizza Distribution Limited | Hospitality | 2019 |
| Kossoff (Caterers) Limited | Real estate | 1947 |
| Kotarja Construction and Investment Ltd | Real estate | 2026 |
| Kottax Ltd | Professional & scientific | 2024 |
| Kovenant Marketing Ltd | Professional & scientific | 2026 |
| KP Edgware Ltd | Hospitality | 2022 |
| Kp&G Limited | Health & social care | 2021 |
| KP55 Limited | Real estate | 2026 |
| Kprs Property Investments Ltd | Real estate | 2022 |
| KPS Mokara Limited | Professional & scientific | 2023 |
| Kpyp Group Ltd | Real estate | 2023 |
| Kreative Corridor Ltd | Wholesale & retail | 2025 |
| Kremen Properties Limited | Real estate | 1957 |
| Kriani Limited | Professional & scientific | 2022 |
| Kris Fortella Limited | Financial services | 2023 |
| KRIS1 Transport Limited | Transport & logistics | 2016 |
| Krisha Properties Limited | Real estate | 2019 |
| Krishna Logistics Limited | Transport & logistics | 2024 |
| Krishnanta Ltd | Wholesale & retail | 2026 |
| Kriss Demolition Ltd | Construction | 2016 |
| Kristalglobe Limited | Wholesale & retail | 2019 |
| Krivana Ltd | Wholesale & retail | 2025 |
| Kroky Ltd | Manufacturing | 2023 |
| Kros Limited | Professional & scientific | 2009 |
| Krosremit Payments Limited | Financial services | 2024 |
| Kroune Ltd | Wholesale & retail | 2024 |
| Kruger Brentt Publishers UK Ltd | Information & communication | 2015 |