| Keshmin Nights Ltd | Extraterritorial | 2024 |
| Kest Developments Limited | Construction | 2014 |
| Kethabanu & Co Limited | Health & social care | 2007 |
| Kettering Store Ltd | Wholesale & retail | 2025 |
| Kettle Home Ltd | Wholesale & retail | 2022 |
| Kevan Witt Associates (2012) Ltd | Professional & scientific | 2012 |
| Kevin Haulage UK Ltd | Transport & logistics | 2021 |
| Kevin Ives Brickwork Ltd | Construction | 2016 |
| Kevin Sandu Ltd | Transport & logistics | 2016 |
| Key Conveyancing Corporation Limited | Professional & scientific | 2025 |
| Key Conveyancing LLP | | 2012 |
| Key Design & Construction Limited | Construction | 2026 |
| Key Home Residential Sales and Lettings Limited | Real estate | 2011 |
| Key Stonework Limited | Manufacturing | 2004 |
| Key to Plumbing Ltd | Construction | 2021 |
| Key Worker Community Interest Company | Administrative & support | 2019 |
| Keybuild Northampton Ltd | Construction | 2020 |
| Keyham Limited | Real estate | 2004 |
| Keys and Co Real Estate Limited | Real estate | 2026 |
| KEYST1 International Consultants Ltd | Professional & scientific | 2014 |
| Keystone and More Limited | Wholesale & retail | 2023 |
| Keystone Building & Renovation Limited | Construction | 2022 |
| Keystone Earth Consulting Ltd | Professional & scientific | 2019 |
| Keystone Education (Northampton) Limited | Information & communication | 2017 |
| Keystone Facades Ltd | Extraterritorial | 2022 |
| Keystone Roofing Ltd | Construction | 2009 |
| Keyto Global Services Limited | Administrative & support | 2021 |
| Keyway Investments Limited | Real estate | 2020 |
| KFC (Kent Fire Consultants) Limited | Public administration | 2014 |
| KFH Services Limited | Professional & scientific | 2020 |
| KFM (Kerala Fresh Meat) Ltd | Wholesale & retail | 2026 |
| Kfsoftware Ltd | Information & communication | 2020 |
| Kgdg Ltd | Professional & scientific | 2025 |
| KGM Hospitality Limited | Hospitality | 2025 |
| KGS Consulting Ltd | Information & communication | 2016 |
| Kgst Enterprise Ltd | Real estate | 2025 |
| Khadi Investments Ltd | Real estate | 2025 |
| Khai Property Staging Limited | Real estate | 2017 |
| Khalqia PVT Ltd | Extraterritorial | 2019 |
| Khalsa Super Store Ltd | Wholesale & retail | 2021 |
| Khanna Sons Properties Ltd | Real estate | 2025 |
| Khanyezi Limited | Health & social care | 2018 |
| Khaos Hair Ltd | Other services | 2019 |
| Khatanabrothers Limited | Wholesale & retail | 2025 |
| Khattak's Mart Ltd | Wholesale & retail | 2025 |
| Khil Properties Limited | Real estate | 2017 |
| Khoros Limited | Wholesale & retail | 2011 |
| Khush Limited | Financial services | 2013 |
| KHY Group Ltd | Wholesale & retail | 2019 |
| Khybar Tandoori Northampton Limited | Hospitality | 2023 |
| Khyber Shop 35 Ltd | Wholesale & retail | 2025 |
| KI Science Limited | Manufacturing | 2016 |
| Kian Services Ltd | Professional & scientific | 2025 |
| Kibeki Transport Ltd | Transport & logistics | 2023 |
| Kibria Green Limited | Wholesale & retail | 2022 |
| Kick OFF Detection Ltd | Other services | 2024 |
| Kick UPS Academy Ltd | Arts & recreation | 2024 |
| Kick-Ups Sports Academy Ltd | Education | 2019 |
| Kickskeenan Ltd | Wholesale & retail | 2024 |
| Kickzorcandy Ltd | Wholesale & retail | 2018 |
| KID Kapichi Ltd | Information & communication | 2021 |
| Kiddies at Home Child Care Limited | Health & social care | 2012 |
| KIDK2 Ltd | Information & communication | 2025 |
| Kidl Services Ltd | Transport & logistics | 2017 |
| Kids 2 US Limited | Health & social care | 2012 |
| Kids of Wilmslow Limited | Education | 2001 |
| Kidsunlimited Group Limited | Education | 2008 |
| Kidsunlimited Limited | Education | 1987 |
| Kieron Conway Limited | Arts & recreation | 2018 |
| Kiffik Biomedical Europe Ltd | Manufacturing | 2021 |
| Kikimish Limited | Administrative & support | 2019 |
| Kilby Property Limited | Real estate | 2020 |
| Kilciauskas Ltd | Other services | 2025 |
| Kilig LDN Ltd | Hospitality | 2021 |
| Killer Lighting Limited | Information & communication | 2013 |
| Kilsby Properties Ltd | Construction | 2016 |
| Kilvington Technologies Ltd | Information & communication | 2025 |
| KIM Developments Holdings Limited | Financial services | 2023 |
| Kimala Ltd | Professional & scientific | 2024 |
| Kimchi Labs Limited | Information & communication | 2013 |
| Kimmicon Limited | Administrative & support | 2026 |
| Kimoksha Telecom Limited | Information & communication | 2024 |
| Kind Minds Health & Wellbeing Limited | Health & social care | 2015 |
| Kinder Cabins Ltd | Construction | 2025 |
| Kinder's Paintjobs Limited | Construction | 2019 |
| Kinderelu Limited | Transport & logistics | 2018 |
| Kinderstart Day Nurseries Limited | Education | 2003 |
| Kindred Education (Bournemouth) LLP | | 2013 |
| Kindred Education (Bromley North) Limited | Health & social care | 2010 |
| Kindred Education (Hanwell) Limited | Education | 1994 |
| Kindred Education (Islington) Limited | Administrative & support | 2001 |
| Kindred Education (Little Learners) Limited | Education | 2012 |
| Kindred Education (NE London) Limited | Education | 2005 |
| Kindred Education (Rayleigh) Limited | Education | 1999 |
| Kindred Education (Westcliff) Limited | Education | 2013 |
| Kindred Education (Wiltshire) Limited | Education | 2009 |
| Kindred Education Limited | Financial services | 2015 |
| Kindred Education Propco Limited | Real estate | 2026 |
| Kindred HR Limited | Administrative & support | 2010 |
| Kinetic Engineering Design Limited | Information & communication | 2007 |