| Kijoff Ltd | Construction | 2019 |
| Killoch Resources Limited | Energy | 2023 |
| Kimel Limited | Real estate | 2023 |
| Kinboat Limited | Health & social care | 2020 |
| Kindave Consulting Limited | Information & communication | 2023 |
| Kingdom Care Recruitment Limited | Health & social care | 2017 |
| Kingdom Palace Limited | Administrative & support | 2026 |
| Kingham Logistics Limited | Transport & logistics | 2024 |
| Kings Autos & Sons Ltd | Wholesale & retail | 2024 |
| Kings Real Estates Ltd | Real estate | 2017 |
| Kings Skip Hire Limited | Water & waste | 2019 |
| Kingston Court Limited | Households | 2001 |
| Kingsworth Consult Limited | Professional & scientific | 2024 |
| Kini Consultancy Services Ltd | Information & communication | 2019 |
| Kinwin Company Limited | Real estate | 1986 |
| KIP Services Ltd | Construction | 2025 |
| Kirwin & Simpson Limited | Administrative & support | 2010 |
| Kitchen Crafty Ltd | Construction | 2022 |
| Kite Contract Cleaning Limited | Administrative & support | 1962 |
| Kival UK Ltd | Construction | 2024 |
| Kiyo Beauty Ltd | Wholesale & retail | 2018 |
| Kizirli Limited | Hospitality | 2025 |
| KJR Carpentry Limited | Construction | 2016 |
| Klacey Belle Limited | Health & social care | 2020 |
| Klasi Ltd | Wholesale & retail | 2019 |
| Klassik Services Limited | Transport & logistics | 2025 |
| Kleen Addicts Limited | Administrative & support | 2025 |
| Kleos-Ebi Ltd | Financial services | 2025 |
| KLG Rental & Management Ltd | Real estate | 2021 |
| Klic Renewables Ltd | Construction | 2023 |
| Klin IT Limited | Information & communication | 2014 |
| KLO Investments Limited | Financial services | 2022 |
| KMD Homes Ltd | Real estate | 2019 |
| KML Finance Ltd | Administrative & support | 2025 |
| KMP Cleaning Services Ltd | Administrative & support | 2018 |
| KN Nebechi Limited | Construction | 2017 |
| Knah Limited | Hospitality | 2022 |
| KNB Estates Limited | Real estate | 2010 |
| KND Group Ltd | Construction | 2017 |
| Knight Dominion Limited | Financial services | 2025 |
| Knight Technical Solutions Ltd | Manufacturing | 2026 |
| Knightsbury Consulting Limited | Information & communication | 2012 |
| KNL Finance Limited | Professional & scientific | 2019 |
| KNL Limited | Construction | 2011 |
| KNM Electrical Contractor's Limited | Manufacturing | 2016 |
| KNOT4GOTTEN Ltd | Health & social care | 2024 |
| Knotntie Tech Ltd | Information & communication | 2024 |
| KNS Enterprise Ltd | Administrative & support | 2022 |
| KNT Property Investments Ltd | Real estate | 2022 |
| KO International Foods Ltd | Real estate | 2023 |
| KO International Ltd | Real estate | 2019 |
| Kobi&Maadhu Limited | Wholesale & retail | 2018 |
| Kobrah Koffee Ltd | Hospitality | 2014 |
| Kogaian Speed Ltd | Transport & logistics | 2016 |
| Koiro Limited | Construction | 2025 |
| Komar Ltd | Transport & logistics | 2017 |
| Kome Accounting Ltd | Education | 2023 |
| Koobb Property Services Ltd | Real estate | 2021 |
| Kopco Limited | Construction | 2018 |
| Koreza Ltd | Hospitality | 2026 |
| Korleone Ltd | Transport & logistics | 2020 |
| Korus- K Property Ltd | Real estate | 2024 |
| Korzen Ltd | Transport & logistics | 2023 |
| Koshoni Ltd | Information & communication | 2024 |
| Koyal Music London Ltd | Information & communication | 2026 |
| KPD Haulage Ltd | Transport & logistics | 2019 |
| KPK Trading Limited | Administrative & support | 2019 |
| KPN Construction Ltd | Construction | 2024 |
| KPR Building Services Ltd | Construction | 2017 |
| KR Ejims Ltd | Real estate | 2025 |
| Krasboy Ltd | Construction | 2014 |
| Krasda Ltd | Health & social care | 2024 |
| Krazy Wheels Ltd | Wholesale & retail | 2017 |
| Kreesh Ltd | Health & social care | 2025 |
| Kris Plumbing&Heating Ltd | Construction | 2018 |
| Krishna London Limited | Wholesale & retail | 2025 |
| Krissfix Ltd | Construction | 2019 |
| Krisz Trans Limited | Transport & logistics | 2017 |
| Krusna Ltd | Construction | 2015 |
| KRV Logistics Ltd | Wholesale & retail | 2020 |
| KS Property Investment Group Ltd | Real estate | 2018 |
| KSK Holdings Ltd | Real estate | 2025 |
| KSN Holdings Limited | Real estate | 2024 |
| KTC Services Ltd | Information & communication | 2022 |
| KTD Services Limited | Health & social care | 2016 |
| Kten Limited | Administrative & support | 2021 |
| KTJ Investments Limited | Real estate | 2024 |
| Kuku Piri Piri Limited | Manufacturing | 2021 |
| Kumar Brothers Ltd | Hospitality | 2018 |
| Kumic Health Care Limited | Health & social care | 2014 |
| Kuzminov Builders Ltd | Construction | 2019 |
| KV Legal Consultancy Ltd | Professional & scientific | 2017 |
| Kvaa Solutions Limited | Professional & scientific | 2025 |
| KVK Healthcare Limited | Public administration | 2024 |
| Kwikfit Shutters Ltd | Construction | 2022 |
| Kwikstart Properties Ltd | Real estate | 2025 |
| KYK Group Ltd | Wholesale & retail | 2018 |
| KYM Marketing Ltd | Professional & scientific | 2025 |
| Kyoto Furniture Limited | Wholesale & retail | 2013 |
| L & S Bespoke Developments Limited | Construction | 2026 |