| Keyline Cars Limited | Wholesale & retail | 2010 |
| Keymax (UK) Limited | Real estate | 2025 |
| Kfcrafts Limited | Manufacturing | 2021 |
| KG Health Care Services Ltd | Health & social care | 2018 |
| Kgap Limited | Health & social care | 2015 |
| Kghuk Ltd | Wholesale & retail | 2023 |
| Khalid & Sons Ltd | Real estate | 2025 |
| Khars Travels Limited | Transport & logistics | 2026 |
| Kiaraah UK Ltd | Wholesale & retail | 2026 |
| Kibriya Enterprises Ltd | Wholesale & retail | 2024 |
| Kickup Sports Ltd | Arts & recreation | 2014 |
| Kids Play Village 2 Ltd | Arts & recreation | 2025 |
| Kilmurray Construction Ltd | Administrative & support | 2017 |
| Kilmurray Developments Limited | Financial services | 2022 |
| Kilmurray Group Limited | Financial services | 2022 |
| Kilmurray Limited | Construction | 2022 |
| Kiln Clinic Limited | Manufacturing | 1995 |
| Kinbek Limited | Transport & logistics | 2016 |
| Kind Wellness Ltd | Arts & recreation | 2026 |
| Kindlewood Homes Ltd | Health & social care | 2025 |
| Kindly Limited | Construction | 2009 |
| Kindness Creations Ltd | Wholesale & retail | 2025 |
| Kindred Cleaning Services Ltd | Administrative & support | 2026 |
| Kinetic Outcomes Ltd | Administrative & support | 2023 |
| Kinetium Corporation Limited | Information & communication | 2012 |
| Kingdom Temple Ltd | Wholesale & retail | 2024 |
| Kingfell Engineering Limited | Manufacturing | 2011 |
| Kinghan & Co Ltd | Manufacturing | 2022 |
| Kings Accounting (Hythe) Ltd | Real estate | 2006 |
| Kings Bookkeeping Ltd | Professional & scientific | 2024 |
| Kings Property Services Ltd | Real estate | 2026 |
| Kinzak London Ltd | Real estate | 2026 |
| Kirk Building & Construction Ltd | Construction | 2021 |
| Kirkby Property Services Ltd | Real estate | 2026 |
| Kirkfield Limited | Manufacturing | 1999 |
| Kitchenz Limited | Hospitality | 2021 |
| KJ Joinery Limited | Real estate | 1996 |
| KJ Optical Solutions Limited | Health & social care | 2016 |
| KJM Investments Ltd | Real estate | 2024 |
| KJM Mechanical Services Ltd | Administrative & support | 2016 |
| Kjmullen Ltd | Administrative & support | 2023 |
| KJP Services Limited | Professional & scientific | 2015 |
| KK Service Brockley Ltd | Wholesale & retail | 2017 |
| Klikdat Limited | Information & communication | 2015 |
| KM4 Limited | Health & social care | 2015 |
| Kmha Consultants Ltd | Professional & scientific | 2024 |
| Knight Audio Technologies Limited | Manufacturing | 2008 |
| Knight Classical Ltd. | Arts & recreation | 2019 |
| Knights Business Supplies Limited | Wholesale & retail | 2003 |
| KNK Fine Line Ltd | Wholesale & retail | 2026 |
| KNK Services Ltd | Information & communication | 2024 |
| KNM Solutions Ltd | Information & communication | 2024 |
| Knockout Waste Control Ltd | Water & waste | 2019 |
| Knole Homes (Bourne END) Ltd | Construction | 2013 |
| Knole Homes (Crowell) Ltd | Real estate | 2011 |
| Knole Homes Limited | Real estate | 2010 |
| Knoll Lawn Tennis Club Limited | Arts & recreation | 1963 |
| Knoll Property Services Ltd | Real estate | 2015 |
| Knoll Rise Services Limited | Administrative & support | 2010 |
| Kobus Properties Limited | Real estate | 2007 |
| Koffee Klub Limited | Hospitality | 2019 |
| Koie Limited | Financial services | 2024 |
| KOJ Professional Services Ltd | Professional & scientific | 2025 |
| Kolver a V L X Limited | Administrative & support | 2011 |
| Korfker Neal Music Ltd | Arts & recreation | 2021 |
| Kovoor Healthcare Limited | Health & social care | 2016 |
| KP Premier Ltd | Wholesale & retail | 2024 |
| KP Restaurants Limited | Hospitality | 2026 |
| KPE Services Limited | Financial services | 2025 |
| KPS (Hadlow) Limited | Construction | 2018 |
| Kpsych Ltd | Health & social care | 2025 |
| KQN Capital Limited | Professional & scientific | 2016 |
| KR Kent Ltd | Real estate | 2022 |
| Kram Deli Ltd | Wholesale & retail | 2014 |
| Kreative Konstructions Limited | Real estate | 2017 |
| Krisha Tech Limited | Information & communication | 2025 |
| Krisol Ltd | Information & communication | 2012 |
| Kristamfe Limited | Administrative & support | 2015 |
| Krivi Bakes Ltd | Hospitality | 2025 |
| KRW Catering Ltd | Hospitality | 2023 |
| KRW Events Ltd | Hospitality | 2025 |
| KRY8 Ltd | Education | 2021 |
| Krzysiek Transport Ltd | Transport & logistics | 2023 |
| KS Construction & Development Ltd | Construction | 2022 |
| KSA Plant Ltd | Transport & logistics | 2017 |
| Ksenia Ltd | Health & social care | 2022 |
| KSS VI Construction Ltd | Construction | 2021 |
| KT Car Sell Ltd | Wholesale & retail | 2025 |
| KT Ellis Group Limited | Real estate | 2022 |
| Ktkid Limited | Real estate | 2023 |
| Kube Print Limited | Manufacturing | 2004 |
| Kuber Investments Ghana Limited | Construction | 2019 |
| KUM Solutions Ltd | Education | 2010 |
| Kurios Integrated Services Limited | Health & social care | 2016 |
| Kurti Property Services Ltd | Construction | 2024 |
| Kuss Facilities and Property Services Ltd | Administrative & support | 2025 |
| Kussan Trading Limited | Hospitality | 2010 |
| Kustom Made Ltd | Professional & scientific | 2022 |
| Kutchenhaus Orpington Ltd | Wholesale & retail | 2023 |
| Kuzey Fish N Co Limited | Hospitality | 2025 |