| Kams & Co UK Ltd | Wholesale & retail | 2011 |
| Kamset Digital Limited | Extraterritorial | 1990 |
| Kamset Limited | Manufacturing | 2024 |
| Kandi Workshop Supplies Limited | Other services | 2024 |
| Kanel London Limited | Other services | 2020 |
| KAQ Limited | Health & social care | 2015 |
| Kara Health Science Limited | Health & social care | 2026 |
| Karakaya Properties Limited | Real estate | 2025 |
| Karakaya Property Limited | Real estate | 2023 |
| Karbontwo Group Limited | Real estate | 2019 |
| Karimba Capital Ltd | Financial services | 2024 |
| Karl Sutton Tattoos Limited | Arts & recreation | 2021 |
| Karnav Limited | Real estate | 2024 |
| Karo Vista Ltd | Professional & scientific | 2026 |
| Karunaratne Associates Ltd | Health & social care | 2010 |
| KAS Facilities Management Services Limited | Construction | 2005 |
| Kast Heating Sales Ltd | Wholesale & retail | 2023 |
| Kast Local Limited | Wholesale & retail | 2023 |
| Katalinak Limited | Construction | 2026 |
| Kathiyawadi Foods (UK) Ltd | Hospitality | 2023 |
| Katie Blake Limited | Manufacturing | 2024 |
| Kaura Property Repairs Ltd | Construction | 2025 |
| Kavern Access & Maintenance Ltd | Construction | 2024 |
| KAY Dynamix Resources Limited | Public administration | 2020 |
| Kayjay Properties Limited | Real estate | 2024 |
| Kaylan Media Ltd | Other services | 2024 |
| Kayleigh Woodford Aesthetics Ltd | Other services | 2025 |
| KB Cafe Limited | Hospitality | 2022 |
| KB Spares Ltd | Wholesale & retail | 2025 |
| KBG Property Maintenance Ltd | Construction | 2016 |
| KBN Automotive Ltd | Transport & logistics | 2016 |
| Kc-Chy Ltd | Hospitality | 2022 |
| KCD Electrical Limited | Construction | 2021 |
| KCI Logistics Ltd | Transport & logistics | 2017 |
| KCS Industries Limited | Real estate | 2003 |
| KD Drylining Ltd | Construction | 2020 |
| KD OFF Licence Limited | Wholesale & retail | 2025 |
| KDC Transport Services Ltd | Transport & logistics | 2024 |
| KE - Flow Solutions Limited | Construction | 2015 |
| KEA Recruitment Ltd | Administrative & support | 2025 |
| Keane Travel Limited | Transport & logistics | 2018 |
| Keeble & Co. Associates Limited | Professional & scientific | 2022 |
| Keegan Kessewnath Rappresentanze Limited | Wholesale & retail | 2022 |
| Keep IT Green Solutions Limited | Professional & scientific | 2021 |
| Keeping Pipework Limited | Construction | 2026 |
| Keily Brien Therapy Ltd | Health & social care | 2025 |
| Kelgray Publishing Group Ltd | Information & communication | 2022 |
| Kelley Davis Photography Ltd | Professional & scientific | 2016 |
| Kelly Hygiene and Aesthetics Limited | Health & social care | 2022 |
| Kelvedon Motor Company Limited | Wholesale & retail | 2004 |
| Kelviro Limited | Administrative & support | 2009 |
| Kemfa Services Ltd | Health & social care | 2017 |
| Kemp Investigations and Legal Services Limited | Extraterritorial | 2016 |
| Kemwealth Limited | Health & social care | 2016 |
| KEN Cameron Limited | Financial services | 2014 |
| Kendal Properties Ltd | Real estate | 1999 |
| Kenexmotors Ltd | Wholesale & retail | 2026 |
| Kenkoo Ltd | Health & social care | 2011 |
| Kennedy Knight Limited | Other services | 2019 |
| Kensington and Chelsea Plumbing and Heating Limited | Construction | 2016 |
| Kent & London Roofing Services Limited | Construction | 2024 |
| Kent Coast Construction Limited | Construction | 2016 |
| Kent House Property Services Limited | Households | 2012 |
| Kentcrete Limited | Construction | 2017 |
| Kenteco Electrical & Renewables Ltd | Construction | 2026 |
| Kentsconstruction Limited | Construction | 2026 |
| Keoo Ltd | Information & communication | 2026 |
| Kepler Homes Ltd | Hospitality | 2014 |
| Kerbwise Limited | Construction | 2025 |
| Kerin Construction Limited | Construction | 2000 |
| Kestutisc Ltd | Transport & logistics | 2020 |
| Kevan Mark Property Ltd | Real estate | 2020 |
| Kevin Kenny Project Services (UK) Limited | Professional & scientific | 2024 |
| Kevin M Thompson Limited | Construction | 2018 |
| KEW Pipe Services Limited | Construction | 2012 |
| Key Complex Ltd | Real estate | 2024 |
| Key Electrical & Data Services Limited | Construction | 2017 |
| Key Lime Ltd | Hospitality | 2015 |
| Key Tutoring Ltd | Administrative & support | 2025 |
| Keysland Limited | Administrative & support | 2000 |
| KF Clinical Services Ltd | Health & social care | 2026 |
| KFR Family Limited | Extraterritorial | 2012 |
| KG Fire Protection Limited | Other services | 2024 |
| KGL Services Limited | Professional & scientific | 2019 |
| KGM Creative Services Ltd | Professional & scientific | 2021 |
| Kgmd Properties Limited | Real estate | 2020 |
| KH Commercial Engineering Services Limited | Wholesale & retail | 2018 |
| Khalil Traders Ltd | Wholesale & retail | 2025 |
| Khans & Khans Holdings Limited | Financial services | 2025 |
| Khans Burgers Limited | Hospitality | 2019 |
| Khanzada & Brothers Limited | Transport & logistics | 2022 |
| Kharis Ministries | Other services | 2010 |
| Khhb Productions Limited | Administrative & support | 2017 |
| KHS Enterprises Limited | Transport & logistics | 2020 |
| Kibo Drywall&Ceilings Ltd | Construction | 2014 |
| Kidoo Limited | Transport & logistics | 2024 |
| Kids Party Wheels Ltd | Administrative & support | 2021 |
| Kiesta Fabrics & Interiors Ltd | Other services | 2022 |
| Kikdeb Limited | Transport & logistics | 2012 |
| Kiki Business Solutions Ltd | Wholesale & retail | 2025 |