| Kalki Health Limited | Wholesale & retail | 2017 |
| Kalpesh Limited | Wholesale & retail | 2002 |
| Kamaly Properties Limited | Real estate | 2023 |
| Kamalytics Limited | Information & communication | 2023 |
| Kamaxx Limited | Construction | 2025 |
| Kamee - Save Limited | Professional & scientific | 1985 |
| Kamgot Limited | Administrative & support | 2022 |
| Kamo Properties Limited | Real estate | 2018 |
| Kamota Limited | Real estate | 2015 |
| KAN Business Consulting Limited | Professional & scientific | 2016 |
| Kanda UK Estates Limited | Real estate | 2024 |
| Kanda UK Investments Ltd | Real estate | 2024 |
| Kanda UK Property Limited | Real estate | 2018 |
| Kangaroo Kids Nursery Limited | Education | 1999 |
| Kanwal SL Ltd | Administrative & support | 2015 |
| Kapoor & Daughters Properties Limited | Real estate | 2023 |
| Karacan Ltd | Hospitality | 2011 |
| Karadi Enterprise (UK) Limited | Information & communication | 2015 |
| Karami Investments Limited | Real estate | 2019 |
| Karan Holding Limited | Real estate | 2026 |
| Karate by Chris Limited | Education | 2024 |
| Karel Group Limited | Financial services | 2025 |
| Karel Investments Limited | Financial services | 2022 |
| Karel Limited | Professional & scientific | 2015 |
| Karion Ltd | Real estate | 2022 |
| Karishi Limited | Wholesale & retail | 2019 |
| Kashman Limited | Real estate | 2021 |
| Katherine Page Media Research Consultancy Limited | Professional & scientific | 2011 |
| Kathys Brewing Company Limited | Wholesale & retail | 2025 |
| Katz Home Vets Ltd | Professional & scientific | 2026 |
| Kaur Enterprises (2025) Limited | Financial services | 2025 |
| Kaurum Limited | Real estate | 2018 |
| Kavan Johal Limited | Health & social care | 2023 |
| Kavin Accountancy Limited | Professional & scientific | 2002 |
| Kavin Holding Ltd | Financial services | 2024 |
| Kavin Real Estate Limited | Real estate | 2025 |
| KAY Venture UK Limited | Information & communication | 2019 |
| Kaya Meat Ltd | Wholesale & retail | 2025 |
| Kayson Green Limited | Wholesale & retail | 1968 |
| Kayvee Limited | Professional & scientific | 2013 |
| KB Brothers Constructions Limited | Construction | 2019 |
| KBB Custom Interiors Limited | Administrative & support | 2014 |
| KBB Services Ltd | Administrative & support | 2024 |
| KBM Services Limited | Households | 2022 |
| Kbruce Consulting Limited | Health & social care | 2014 |
| KBS Care Limited | Health & social care | 2024 |
| KC & R Properties Limited | Administrative & support | 2012 |
| KC Mehta Ltd | Wholesale & retail | 2019 |
| KD & Sons Ltd | Construction | 2019 |
| KDI Consultancy Limited | Information & communication | 2009 |
| KDM Advisory Ltd | Administrative & support | 2022 |
| Kdsa Investments Propco Ltd | Construction | 2025 |
| Kdss Management Ltd | Households | 2026 |
| Keener Inspiration Ltd. | Professional & scientific | 2013 |
| Keepmegreen Ltd | Administrative & support | 2018 |
| Keith Flower & Co Ltd | Professional & scientific | 2020 |
| KEL Services Limited | Wholesale & retail | 2005 |
| Keldon Flat Management Company Limited | Households | 1981 |
| Keli LLP | | 2015 |
| Kellcorp Limited | Wholesale & retail | 2022 |
| Kello Bucks Investments Limited | Professional & scientific | 2017 |
| KEN Evans 204 Ltd | Construction | 2023 |
| KEN Motors Limited | Wholesale & retail | 2005 |
| Kencade Recovery Limited | Construction | 2017 |
| Kenobi Ltd | Administrative & support | 2010 |
| Kensal Green Londis Limited | Wholesale & retail | 2010 |
| Kensaltown Arts Limited | Financial services | 2026 |
| Kensaltown Limited | Administrative & support | 2008 |
| Kensaltown Music Publishing Limited | Information & communication | 2026 |
| Kensaltown Studios London Limited | Information & communication | 2021 |
| Kensho Limited | Professional & scientific | 2010 |
| Kensington and Chelsea Times Limited | Information & communication | 2008 |
| Kensington Estate and Management Limited | Real estate | 2019 |
| Kensingtons HC Ltd | Wholesale & retail | 2024 |
| Kenton Road HA3 Ltd | Real estate | 2022 |
| Kernel Communications and Advocacy Limited | Professional & scientific | 2020 |
| Kesar Holdings Limited | Real estate | 2022 |
| Kesendo Ltd | Health & social care | 2024 |
| KEW Road Dental Limited | Health & social care | 2017 |
| Key Red Limited | Arts & recreation | 1999 |
| Keya Consulting Limited | Information & communication | 2010 |
| Keyhale Limited | Construction | 2005 |
| Keynes Property Holdings Ltd | Real estate | 2026 |
| KG Physio Ltd | Health & social care | 2014 |
| KH Twenty Four Ltd | Professional & scientific | 2020 |
| Khela Creative Limited | Professional & scientific | 2024 |
| Khgr Freeholds Limited | Real estate | 2019 |
| KHGR1 Limited | Real estate | 2018 |
| Kian Consultancy Limited | Construction | 2013 |
| Kict Solutions Ltd | Information & communication | 2024 |
| Kidoouk Ltd | Wholesale & retail | 2025 |
| Kids Kingdom Day Care Limited | Education | 2008 |
| Kikis Daughters Holdings Limited | Financial services | 2018 |
| Kikis Group Limited | Financial services | 2018 |
| Kikis Holdings Limited | Financial services | 2018 |
| Kikis Quality Meats Limited | Wholesale & retail | 2010 |
| Killarney Limited | Real estate | 2020 |
| Killer B Music Limited | Information & communication | 2010 |
| Kilmartin Estates Limited | Real estate | 2022 |
| Kineso Physiotherapy Ltd | Health & social care | 2019 |