| Kalid Ltd | Real estate | 2021 |
| Kandour Apparel Ltd | Wholesale & retail | 2023 |
| Kanina London Ltd | Manufacturing | 2016 |
| Karaluxe London Ltd | Other services | 2026 |
| Karen Giles Consulting Ltd | Professional & scientific | 2019 |
| Kariba Consulting Ltd | Professional & scientific | 2019 |
| Karm EYE Care Ltd | Wholesale & retail | 2025 |
| Karm Group Holdings Limited | Financial services | 2021 |
| Karm Investments Limited | Financial services | 2019 |
| Karm Lynton Gardens Ltd | Real estate | 2020 |
| Karma Assets Limited | Professional & scientific | 2012 |
| Karun Limited | Hospitality | 2024 |
| Karz Transportation Ltd | Transport & logistics | 2017 |
| Kastrati Welding Ltd | Construction | 2022 |
| Katie & LEE Nails Limited | Other services | 2024 |
| Katybuild Limited | Construction | 2008 |
| Kazen KAI Hullbridge LLP | | 2026 |
| Kazen KAI Ltd | Arts & recreation | 2002 |
| Kazen KAI Martial Arts Ltd | Arts & recreation | 2024 |
| KBD Solutions Limited | Professional & scientific | 2021 |
| KBN Property Services Ltd | Real estate | 2022 |
| KBR Land Consulting Ltd | Professional & scientific | 2026 |
| Kcare Ltd | Wholesale & retail | 2021 |
| KD Residential Care Limited | Health & social care | 2024 |
| KDF Extensions Limited | Construction | 2019 |
| KDH Consultants Ltd | Professional & scientific | 2010 |
| KE Insight Solutions Ltd | Health & social care | 2025 |
| Kebabish Original Ltd | Professional & scientific | 2005 |
| Keccee Ltd | Wholesale & retail | 2026 |
| Keep IT Vending Ltd | Wholesale & retail | 2025 |
| Keep Your Kool Ltd | Manufacturing | 2025 |
| Keepinitgrimy Ltd | Information & communication | 2016 |
| Kegray Ltd | Professional & scientific | 2021 |
| Keiko Properties Ltd | Real estate | 2022 |
| Kellestudio Group Limited | Education | 2024 |
| Kelwel Care Homes Ltd | Health & social care | 2024 |
| Kelwel Education Services Ltd | Education | 2024 |
| Kelwel Fostering Ltd | Health & social care | 2019 |
| Kelwel Holdings Ltd | Financial services | 2022 |
| Kelwel Properties Limited | Real estate | 2025 |
| Kelwel Recruitment Services Ltd | Administrative & support | 2025 |
| Kelwel Technologies Limited | Information & communication | 2024 |
| Kenda Finance Limited | Financial services | 2020 |
| Kenda Investments Limited | Financial services | 2012 |
| Kenda Property Ltd | Real estate | 2018 |
| Kends Investment Ltd | Real estate | 2016 |
| Kenmorr Limited | Professional & scientific | 2023 |
| Kennway Francis Holdings Limited | Financial services | 2023 |
| Kennway Francis Limited | Financial services | 2017 |
| Kensington Place (Freehold) Limited | Households | 2016 |
| Kenston Business London Ltd | Professional & scientific | 2024 |
| Kenston International Advisory UK Ltd | Professional & scientific | 2025 |
| Kent Accoustics Ltd | Construction | 2000 |
| Kent Tiling Ltd | Construction | 2015 |
| Kentish Air Conditioning Ltd | Construction | 2026 |
| Kenzo Renovations Ltd | Construction | 2025 |
| Kerbgreen Limited | Real estate | 1984 |
| Kerman Properties Ltd | Real estate | 2021 |
| Keska Investments Limited | Real estate | 2017 |
| Kestrel 2 Bidco Limited | Financial services | 2019 |
| Kestrel 2 Holdings Limited | Financial services | 2018 |
| Kestrel Loans NO. 4 Limited | Financial services | 2013 |
| Kestrel Loans NO.5 Limited | Financial services | 2020 |
| Kestrel Loans NO.6 Limited | Financial services | 2020 |
| Kestrel NO. 4 Limited | Financial services | 2013 |
| Kestrel NO. 5 Limited | Financial services | 2021 |
| Kettle Sourcing Ltd | Wholesale & retail | 2025 |
| KEW Health and Beauty (Holdings) Limited | Professional & scientific | 2006 |
| KEW Health and Beauty (Manufacturing) Limited | Administrative & support | 2017 |
| KEW Health and Beauty (U K) Ltd | Administrative & support | 2017 |
| KEW Health and Beauty Limited | Manufacturing | 2004 |
| Key Gardens Limited | Administrative & support | 2026 |
| Keyhost Limited | Professional & scientific | 1995 |
| Keynote Marketing Limited | Manufacturing | 2020 |
| Keystone Flat Roofing Ltd | Construction | 2021 |
| KF Entropy Consultants Limited | Administrative & support | 2010 |
| KGK Construction Support Services Ltd | Construction | 2007 |
| KGK Contractors Ltd | Construction | 2016 |
| KH Assets Limited | Construction | 2015 |
| Khater Professional Plumbing Services Limited | Construction | 2016 |
| KIA Electrical Ltd | Manufacturing | 2013 |
| Kiaran Construction Ltd | Construction | 2019 |
| Kickstartup CIC | Administrative & support | 2026 |
| Kids Motocross Holidays Ltd | Real estate | 2020 |
| Kier and Countryside JV NO1 LLP | | 2025 |
| Kier Countryside Great Haddon East LLP | | 2024 |
| Kier Countryside Holdings 1 LLP | | 2023 |
| Kier Countryside Holdings 2 LLP | | 2023 |
| Kier Countryside Laindon Road LLP | | 2025 |
| Kier Countryside Saffron Walden LLP | | 2024 |
| Kier Countryside South Wokingham LLP | | 2025 |
| Kier Countryside Watford LLP | | 2025 |
| Kier Tech Ltd | Manufacturing | 2025 |
| Kilmarnock Equestrian Centre Ltd. | Other services | 2021 |
| Kimi Engineering Ltd | Other services | 2021 |
| Kind Contractors Ltd | Administrative & support | 2020 |
| Kindred Holdings Ltd | Financial services | 2016 |
| Kine Property Ltd | Real estate | 2022 |
| Kinesis Building Services Ltd | Construction | 2021 |
| Kinetic Global Limited | Wholesale & retail | 2010 |