| Key Produce Limited | Administrative & support | 2008 |
| Keyboard Enterprise Limited | Information & communication | 2013 |
| Keyhome Lettings Ltd | Wholesale & retail | 2024 |
| Keystone Music Ltd | Arts & recreation | 2022 |
| KG S Pubs Limited | Hospitality | 2025 |
| KGB 25 Ltd | Transport & logistics | 2025 |
| Khadija Hanif Ltd | Wholesale & retail | 2021 |
| Khaira’S House Limited | Households | 2023 |
| Khalij Foundation Ltd | Extraterritorial | 2014 |
| Khalij Real Estate Limited | Extraterritorial | 2015 |
| Khalij Services Ltd | Professional & scientific | 2017 |
| Kialux Limited | Construction | 2025 |
| Kicking Tyres Ltd | Information & communication | 2025 |
| Kids Play Bouncy Castles Ltd | Other services | 2017 |
| Kidstreet Limited | Education | 1998 |
| Kidstreet Nursery Limited | Education | 2014 |
| Kiki Juices Limited | Manufacturing | 2026 |
| Kiks-Bishop Ltd | Hospitality | 2020 |
| Kiks-Broxbourne Ltd | Hospitality | 2020 |
| Kiks-Chingford Ltd | Hospitality | 2020 |
| Kiks-Ware Ltd | Hospitality | 2020 |
| Kilby & Co Ltd | Professional & scientific | 2011 |
| Kilmorie Investments LLP | | 2006 |
| Kilmorie Properties Limited | Real estate | 2006 |
| Kilofrequency Limited | Financial services | 2013 |
| King's Oak Hotel (2009) Limited | Hospitality | 2009 |
| King's Property Maintenance Ltd | Construction | 2025 |
| Kings Hill Services Limited | Professional & scientific | 2000 |
| Kingsbridge Capital Ltd | Real estate | 2018 |
| Kingsbridge Surbiton Limited | Real estate | 2024 |
| Kingsleys Estate Agents Limited | Real estate | 2023 |
| Kingsmead Lodge Management Limited | Households | 1968 |
| Kingsmead Roofing Ltd | Construction | 2020 |
| Kingswood Terrace Residents Company Limited | Households | 1994 |
| Kinmar Limited | Real estate | 2025 |
| Kinsey People Solutions Ltd | Administrative & support | 2019 |
| Kintali and Voonna Properties Ltd | Real estate | 2026 |
| Kishkin Ltd | Wholesale & retail | 2024 |
| Kitasta Transport Ltd | Transport & logistics | 2022 |
| Kitchen Fitters 4 U Ltd | Construction | 2018 |
| Kitewood (Creekside) Limited | Real estate | 2016 |
| Kiwi Analytics Limited | Financial services | 2026 |
| Kizzy Property Ltd | Real estate | 2023 |
| KJF Production Services Ltd | Information & communication | 2025 |
| KJR Property Group Ltd | Real estate | 2019 |
| KK & TK Properties Ltd | Real estate | 2022 |
| KK Hollies Road Ltd | Real estate | 2025 |
| Klas Transport Limited | Transport & logistics | 2022 |
| Klasido Limited | Construction | 2018 |
| Klein CC Limited | Real estate | 2025 |
| KLG Property Ltd | Real estate | 2015 |
| KLK Communications Limited | Professional & scientific | 1994 |
| Klub 1945 Ltd | Real estate | 2024 |
| Kluge and Flint LP | | 2023 |
| Kluge and Mcgrath LP | | 2023 |
| KM4HR Recruitment Solutions Limited | Administrative & support | 2017 |
| KMA Solutions Limited | Professional & scientific | 2011 |
| Kmak Ltd | Administrative & support | 2017 |
| KMC Management Ltd | Professional & scientific | 2018 |
| KML Group Holdings Ltd | Financial services | 2024 |
| KML Property Investments Ltd | Real estate | 2024 |
| KMS Management Services Limited | Construction | 2016 |
| Knidos Enterprises Limited | Construction | 2024 |
| Knight Security Management Ltd | Administrative & support | 2017 |
| Knighton Green (Buckhurst Hill) Management Company Limited | Households | 1987 |
| Knighton Green Limited | Households | 1990 |
| Knights Protection Limited | Administrative & support | 2025 |
| KNT Ltd | Transport & logistics | 2023 |
| KO Prop Ltd | Real estate | 2025 |
| Konstrakt Investments Ltd | Real estate | 2025 |
| Kool Tidy Products Ltd | Wholesale & retail | 2019 |
| Kopanski Ltd | Real estate | 2026 |
| KP Creative Vision Limited | Professional & scientific | 2020 |
| KP Marquees Limited | Other services | 2025 |
| KP Painting Solutions Ltd | Construction | 2025 |
| KPF Rivas Group Ltd | Other services | 2021 |
| KPN Contractors Ltd | Construction | 2023 |
| Kpsdata Limited | Information & communication | 2014 |
| KR Consulting Solutions Ltd | Education | 2021 |
| KRC Controls Limited | Construction | 2007 |
| Kricx Ltd | Financial services | 2019 |
| Krimah Ltd | Wholesale & retail | 2015 |
| Krop Ltd | Real estate | 2025 |
| Krrish Assets Cheam Investments Limited | Real estate | 2023 |
| Krrish Assets Cheam Limited | Real estate | 2020 |
| Krrish Assets Investments Limited | Real estate | 2021 |
| Krrish Assets LLP | | 2019 |
| Krrish Atrium Holdings Limited | Financial services | 2022 |
| Krrish Atrium Limited | Construction | 2022 |
| Krrish Capital LLP | | 2018 |
| Krrish Cleeve Court Limited | Transport & logistics | 2020 |
| Krrish Cleeve Limited | Financial services | 2020 |
| Krrish Court Ltd | Other services | 2018 |
| Krrish Kensington KNG Limited | Real estate | 2022 |
| Krrish Kensington Limited | Real estate | 2022 |
| Krrish Lakshmi Ltd | Real estate | 2021 |
| Krrish Portfolio Cheam Limited | Real estate | 2020 |
| Krrish Reading Limited | Real estate | 2021 |
| Krrish Ring Limited | Real estate | 2022 |
| Krrish Ventures Holdings Limited | Financial services | 2022 |