| Keltic 4 Sportswear Ltd | Manufacturing | 2022 |
| Kemeys Range 1967 Limited | Extraterritorial | 2014 |
| Kenaitin Media Ltd | Arts & recreation | 2022 |
| Kendon Farm Limited | Transport & logistics | 2022 |
| Kenkel Supply Consulting Ltd | Professional & scientific | 2020 |
| Kentorque Technologies Ltd | Information & communication | 2020 |
| Kenvins Cars & Commercial Sales Limited | Wholesale & retail | 2013 |
| Keresley Footcare Limited | Health & social care | 2014 |
| Kernowcopia Limited | Professional & scientific | 2013 |
| Kesh (Newport) Ltd | Wholesale & retail | 2016 |
| Kesh Travel Ltd | Transport & logistics | 2025 |
| Keteloda Limited | Administrative & support | 2021 |
| Kevin O’Boyle Consulting Ltd | Professional & scientific | 2018 |
| Kevin Ward Media Limited | Professional & scientific | 2016 |
| Key Acquisitions Ltd | Extraterritorial | 2025 |
| Key GS (Engineering Design) Ltd | Professional & scientific | 2016 |
| Key LET Holdings Limited | Real estate | 2019 |
| Key Vision Properties Ltd | Real estate | 2021 |
| Keystone Care Solutions Limited | Health & social care | 2026 |
| Keystone Structural Engineering (SW) Limited | Construction | 2013 |
| KG Delivery Services Limited | Transport & logistics | 2025 |
| KG Traffic Management Support Ltd | Construction | 2022 |
| KGB Brickwork Limited | Construction | 2023 |
| KGB Inspection Services Ltd | Construction | 2012 |
| KGB Plant & AG Ltd | Agriculture & fishing | 2024 |
| KH Clinical Solutions Ltd | Education | 2025 |
| KH Fabrications (IOW) Limited | Manufacturing | 2016 |
| KH9 Promotions Ltd | Arts & recreation | 2021 |
| Khalid Holdings Ltd | Wholesale & retail | 2022 |
| Khalid Property Management Ltd | Real estate | 2021 |
| Khalis Barbers Ltd | Other services | 2020 |
| Khans Spice Limited | Hospitality | 2025 |
| Khattak Aviation Ltd | Manufacturing | 2026 |
| Khepera Consulting Ltd | Professional & scientific | 2026 |
| Khshisha Ltd | Wholesale & retail | 2025 |
| KHT Apartments Limited | Hospitality | 2024 |
| Kiddiecross Ltd | Health & social care | 2023 |
| Kids Kicks Community Interest Company | Other services | 2025 |
| Kieran Mckay Limited | Information & communication | 2018 |
| KIH Technologies Ltd | Information & communication | 2026 |
| Kilgannon Ltd | Administrative & support | 2018 |
| Kiln Pizza Ltd | Hospitality | 2025 |
| Kilowatt Electrics Limited | Construction | 2023 |
| Kilowatt Properties Ltd | Real estate | 2020 |
| Kilowatt Renewables Limited | Construction | 2019 |
| Kilsby & Williams LLP | | 2003 |
| Kinase Employee Ownership Trustee Limited | Professional & scientific | 2025 |
| Kinase Ltd | Professional & scientific | 2010 |
| Kindcommerce Limited | Wholesale & retail | 2025 |
| Kingcoed Holdings Limited | Financial services | 2022 |
| Kingdom Counselling Limited | Health & social care | 2025 |
| Kingdom Health & Social Care Services Limited | Administrative & support | 2023 |
| Kingdom Properties (South Wales) Limited | Real estate | 2024 |
| Kingdom Property Development Ltd | Real estate | 2017 |
| Kingdom Renovations Limited | Construction | 2021 |
| Kingdom Waters Ltd | Construction | 2013 |
| Kings & Queens Ltd | Wholesale & retail | 2006 |
| Kingsacre (Management) Limited | Real estate | 1986 |
| Kingslea Management Co. Limited | Households | 1996 |
| Kingsley Bespoke Homes Ltd | Construction | 2021 |
| Kingsley Build Group Ltd | Manufacturing | 2017 |
| Kingsley Lettings Ltd | Real estate | 2023 |
| Kingsley Wealth Management Ltd | Professional & scientific | 2019 |
| Kingsmere Management Co. Limited | Households | 1998 |
| Kingston Apartments Ltd | Real estate | 2002 |
| Kingston Commercial Services Ltd | Professional & scientific | 2025 |
| Kingston Newell Limited | Real estate | 2003 |
| Kingsview IOW Freehold Limited | Real estate | 2011 |
| Kingsway (Cowes) Management Co Limited | Households | 1997 |
| Kingsway Building Services Ltd | Construction | 2024 |
| Kingsway Centre Management Ltd | Real estate | 2023 |
| Kingsway Centre Services Ltd | Administrative & support | 2024 |
| Kingsway Chairs Ltd | Real estate | 2024 |
| Kingsway Piano Corporation Ltd | Other services | 2026 |
| Kingswell Heavy Haulage Limited | Transport & logistics | 2015 |
| Kington-Agricultural Ltd | Agriculture & fishing | 2023 |
| Kingtree Blasting Limited | Administrative & support | 2018 |
| Kingtree Haulage Limited | Transport & logistics | 2012 |
| Kinkinetics Limited | Health & social care | 2024 |
| Kinn Kinn Ltd | Hospitality | 2024 |
| Kipbea IT Limited | Information & communication | 2018 |
| Kippertie (UK) Limited | Construction | 2002 |
| Kirkman Holdings Ltd | Real estate | 2021 |
| Kirmel Ltd | Administrative & support | 2026 |
| Kirsty Bridgewater Retail Ltd | Wholesale & retail | 2022 |
| Kirsty Ford Trading Ltd | Arts & recreation | 2022 |
| Kirsty Sailes Independent Funeral Directors Ltd | Other services | 2019 |
| Kirton Plumbing & Heating Ltd | Construction | 2008 |
| Kiss Music Limited | Arts & recreation | 2016 |
| Kitchen Civils (Holdings) Limited | Administrative & support | 2015 |
| Kitchen Civils Limited | Construction | 2013 |
| Kitchen Design Studio (Bridgend) Ltd | Wholesale & retail | 2004 |
| Kitchen Investments Limited | Real estate | 2024 |
| Kitchen Workshop Limited | Administrative & support | 2010 |
| Kitsie Promotions Limited | Professional & scientific | 2023 |
| Kiwi (AML) Search Limited | Information & communication | 2026 |
| Kiwi (ENG) Search Limited | Information & communication | 2026 |
| Kiwi (WAL) Search Limited | Information & communication | 2026 |
| Kizzofit Ltd | Arts & recreation | 2025 |
| KJ Kitchens Ltd | Hospitality | 2025 |