| KNK Investments Ltd | Real estate | 2021 |
| Knowhow Decorating Services Ltd | Construction | 2018 |
| Knowhow Developments Ltd | Construction | 2024 |
| Knowles Care Home Limited | Health & social care | 2006 |
| KO IT Consulting Limited | Extraterritorial | 2021 |
| Ko'B Care Limited | Extraterritorial | 1995 |
| Ko'T Consultancy Services Ltd | Professional & scientific | 2022 |
| Kodelcius Ltd | Education | 2015 |
| Kodwell Technology INT Ltd | Wholesale & retail | 2015 |
| Kofelle Medical Ltd | Health & social care | 2026 |
| Kognition Ltd | Health & social care | 2018 |
| Kohinoor Solutions Limited | Information & communication | 2019 |
| Kohli Investments Limited | Households | 2015 |
| Kojan Transport Ltd | Wholesale & retail | 2018 |
| Kokoni Limited | Households | 2025 |
| Kolor Backdrop Studio Ltd | Manufacturing | 2020 |
| Komodo Property Limited | Real estate | 2021 |
| Konstra Group Limited | Professional & scientific | 2016 |
| Konsw Ltd | Construction | 2020 |
| Konvergex Limited | Information & communication | 2020 |
| Konvershon Logistics Ltd | Transport & logistics | 2023 |
| Koronfel Medics Ltd | Health & social care | 2014 |
| Korsan UK Limited | Hospitality | 2023 |
| Kose Fish and Chips Ltd | Hospitality | 2025 |
| KPG Ltd | Construction | 2016 |
| KPM Health Ltd | Wholesale & retail | 2025 |
| KPM Property Investments Ltd | Hospitality | 2025 |
| KPS Links Ltd | Construction | 2017 |
| Kraft Foods Investment Holdings UK Limited | Professional & scientific | 2011 |
| Kraft Foods UK IP & Production Holdings Limited | Professional & scientific | 2011 |
| Kreashan Ltd | Wholesale & retail | 2023 |
| Krinva Limited | Manufacturing | 2024 |
| Kris Contractors Ltd | Construction | 2019 |
| KRK Homes Ltd | Real estate | 2026 |
| Krushni Residential Ltd | Real estate | 2024 |
| KS Electrical Systems Ltd | Wholesale & retail | 2023 |
| KS Electrical UK Services Ltd | Construction | 2025 |
| KS Emporium Limited | Wholesale & retail | 2022 |
| KS Rail Ltd | Professional & scientific | 2013 |
| KS Sidhu Building & Roofing Ltd | Construction | 2024 |
| KSB Plumbing & Heating Solutions Ltd | Construction | 2021 |
| Ksgo Partners Ltd | Wholesale & retail | 2025 |
| Ksher Wikaas UK Ltd | Other services | 2017 |
| KSL Arcworks Ltd | Manufacturing | 2024 |
| KSR Build Ltd | Construction | 2014 |
| KSS Carpets and Flooring Limited | Construction | 2024 |
| Kssk Ltd | Real estate | 2024 |
| Kssp Ltd | Hospitality | 2025 |
| Kstreet Properties Ltd | Real estate | 2026 |
| Kt's Barbershop Limited | Administrative & support | 2010 |
| KTN Properties Ltd | Real estate | 2025 |
| Kudos 1430 Limited | Professional & scientific | 2011 |
| Kudos Commercial Limited | Construction | 2025 |
| Kudos Entertainment (UK) Limited | Arts & recreation | 2014 |
| Kudos Property Limited | Real estate | 2015 |
| Kudos Roadshow Ltd | Arts & recreation | 2009 |
| Kufa Ltd | Real estate | 2023 |
| Kuki and Shelly Limited | Wholesale & retail | 2024 |
| Kuku Peri Peri MT Ltd | Hospitality | 2023 |
| Kureemun Books Ltd | Information & communication | 2019 |
| Kureemun Groups Ltd | Information & communication | 2021 |
| Kureemun Productions Ltd | Professional & scientific | 2018 |
| Kurv London Ltd | Transport & logistics | 2020 |
| KVJ2 Ltd | Information & communication | 2023 |
| KWF Constructions Ltd | Construction | 2017 |
| Kwid Ltd | Real estate | 2023 |
| Kwik Move Consultancy Ltd | Professional & scientific | 2023 |
| KY Motors Ltd | Wholesale & retail | 2024 |
| Kyem Media Ltd | Information & communication | 2018 |
| Kyere Digital Ltd | Information & communication | 2019 |
| KYM Trading UK Ltd | Wholesale & retail | 2024 |
| KZA Enterprises Limited | Construction | 2024 |
| KZR Coffee Ltd | Hospitality | 2018 |
| L & D School Ltd | Education | 2024 |
| L & H Build and Design Limited | Construction | 2023 |
| L & K Housing Ltd | Real estate | 2020 |
| L & L Law Ltd | Professional & scientific | 2023 |
| L Hodge Engineers (UK) Limited | Manufacturing | 2004 |
| L.Conlon Investments Ltd | Real estate | 2023 |
| LA Business Recovery Limited | Professional & scientific | 2014 |
| LA Esencia Limited | Wholesale & retail | 2016 |
| LA Jade Ltd | Wholesale & retail | 2025 |
| LA Marquise Ltd | Professional & scientific | 2024 |
| LA Serene Ltd | Professional & scientific | 2019 |
| LA Shade Ltd | Wholesale & retail | 2025 |
| LA Vaastu Ltd | Professional & scientific | 2012 |
| LA Vida Europe Limited | Other services | 2002 |
| LA Vida Holdings Ltd | Financial services | 2026 |
| Laadi Green Homes Limited | Real estate | 2021 |
| Laash Pizza Ltd | Hospitality | 2020 |
| LAB Consulting Services Ltd | Professional & scientific | 2025 |
| Label Punjab Ltd | Wholesale & retail | 2023 |
| Labelle Athletics Ltd | Arts & recreation | 2026 |
| Labib Property Ltd | Real estate | 2022 |
| Laboratory Maintenance Services Limited | | 1965 |
| Lachhar Limited | Financial services | 2023 |
| Lachhar Properties Limited | Real estate | 2024 |
| Lacnung Ltd | Financial services | 2025 |
| Lady Electric Limited | Construction | 2021 |
| Laila’S Cafe Limited | Wholesale & retail | 2025 |