| Kathy James Consulting Ltd | Professional & scientific | 2017 |
| Katie Gentle Garden Design Ltd | Administrative & support | 2023 |
| Katie Hopkins Productions Ltd | Information & communication | 2015 |
| Katoro Green Limited | Administrative & support | 2020 |
| Katrina Byrne Litigation Ltd | Professional & scientific | 2016 |
| Kauf Mora Ltd | Wholesale & retail | 2026 |
| Kavani Property Limited | Real estate | 2022 |
| Kaylinks Cares Ltd | Health & social care | 2025 |
| Kaylo Property Investment Ltd | Hospitality | 2022 |
| KAYSERI38 Ltd | Hospitality | 2025 |
| KBB Partnerships Ltd | Construction | 2014 |
| KBR Capital Ltd | Financial services | 2025 |
| KBR Developments Limited | Construction | 2022 |
| KBS Signs and Design Limited | Manufacturing | 1990 |
| KCM Kitchens Ltd | Wholesale & retail | 2021 |
| Kcmc Investment Ltd | Real estate | 2021 |
| KDX Property Ltd | Real estate | 2026 |
| KEB Cars Ltd | Transport & logistics | 2023 |
| Kebab & Pizza (ST Austells) Ltd | Hospitality | 2024 |
| Kebabs (Plymouth) Limited | Hospitality | 1998 |
| KED-EX-71 Ltd | Hospitality | 2025 |
| Keeling Healthcare Limited | Health & social care | 2016 |
| Keepingshortaccounts Limited | Education | 2024 |
| Keith Green Consulting (UK) Limited | Administrative & support | 2015 |
| Keith Roberts (Electrical) Limited | Construction | 2011 |
| Kekdemsa Ltd | Real estate | 2026 |
| Kelford Cafes Limited | Hospitality | 1962 |
| Kelleo Investments Ltd | Real estate | 2023 |
| Kelleo Ltd | Real estate | 2019 |
| Kelleo Properties Limited | Real estate | 2024 |
| Kelly & Kelly Consultancy Ltd | Professional & scientific | 2023 |
| Kelpie (Devon) Limited | Health & social care | 2019 |
| Kelton Homes Ltd | Real estate | 2019 |
| Kelton Property Solutions Ltd | Real estate | 2019 |
| KEM Accounting Ltd | Professional & scientific | 2025 |
| Kenbury Wood Limited | Water & waste | 1986 |
| Kenex Engineering Ltd | Manufacturing | 2010 |
| Kenkay Services Ltd | Administrative & support | 2025 |
| Kennco Limited | Administrative & support | 2026 |
| Kenny Consultancy Limited | Construction | 2018 |
| Kensa Ledgers Limited | Professional & scientific | 2021 |
| Kensa Studios Ltd | Professional & scientific | 2015 |
| Kensington Court Ltd | Administrative & support | 2014 |
| Kent House Dental Practice Ltd | Health & social care | 2025 |
| Kenton Mews Management Company Limited | Households | 2020 |
| Kenwayhall Ltd | Information & communication | 2016 |
| Kenyan Educational Sponsorship CIC | Administrative & support | 2021 |
| Kerala Store Limited | Wholesale & retail | 2024 |
| Kernow Dine and Deli Ltd | Wholesale & retail | 2023 |
| Kernow the Old Inn Limited | Hospitality | 2015 |
| Kernyk Holdings Limited | Financial services | 2021 |
| Kerridge Homes Ltd | Real estate | 2024 |
| Kersell Property Management Limited | Households | 2023 |
| Kettle Co Holdings Limited | Professional & scientific | 2014 |
| Kettle Kitchens Limited | Wholesale & retail | 2007 |
| Kettlehouse Enterprises Limited | Education | 2023 |
| Kevin Hankin Travel Counsellors Ltd | Administrative & support | 2014 |
| Kevin J Furzer Limited | Construction | 2009 |
| Kevin Pilgrim Holdings Limited | Financial services | 2023 |
| Kevin Pilgrim Limited | Manufacturing | 2012 |
| Kewcroft Limited | Agriculture & fishing | 2013 |
| Key 4 Key Homes Ltd. | Real estate | 2021 |
| Key Coaching Ltd | Professional & scientific | 2024 |
| Key Oak Stays Ltd | Real estate | 2024 |
| Key Teachers Ltd | Administrative & support | 2024 |
| Key Venture Solutions Limited | Wholesale & retail | 2019 |
| Keys Online Ltd | Information & communication | 2024 |
| Keystar Ltd | Real estate | 2015 |
| Keytec (GB) Limited | Manufacturing | 1930 |
| Keywise Cars Limited | Wholesale & retail | 2000 |
| KF1 Capital Limited | Financial services | 2023 |
| KG Assets Limited | Real estate | 2026 |
| KG Assist Ltd | Construction | 2017 |
| KG Roofing SW Ltd | Construction | 2024 |
| KGK Holdings Limited | Real estate | 2018 |
| KGM Civil Services Ltd | Water & waste | 2025 |
| KH Exeter Ltd | Hospitality | 2022 |
| KH One Limited | Professional & scientific | 1999 |
| Khanh CHI Pham Limited | Other services | 2024 |
| Kharoti E-Commerce Ltd | Wholesale & retail | 2025 |
| KIA ORA LET Ltd | Real estate | 2025 |
| KIA ORA Ltd | Households | 2019 |
| Kickline Touring Theatre Company Limited | Arts & recreation | 2013 |
| Kids Hub EXE Limited | Wholesale & retail | 2019 |
| Kidsan Property Limited | Real estate | 2021 |
| Kiki Bay Limited | Real estate | 2021 |
| Kildare Holdings Limited | Construction | 2023 |
| Kilgraston Medical Limited | Health & social care | 2016 |
| Killen Consulting Limited | Professional & scientific | 2015 |
| Kiln Ltd | Wholesale & retail | 2026 |
| Kimari Consulting Ltd | Public administration | 2025 |
| Kimblewick Limited | Real estate | 2021 |
| KIN Buildings Limited | Construction | 2025 |
| KIN Khao Foods Limited | Hospitality | 2020 |
| Kindnest Care Home Limited | Health & social care | 2025 |
| King & Kearey,Limited | Transport & logistics | 1939 |
| King Street Amenity Limited | Households | 2005 |
| Kingdom & Partners Ltd | Professional & scientific | 2025 |
| Kingfisher Day Services Limited | Construction | 2013 |
| Kingfisher Estates LLP | | 2023 |