| Klevi Painting & Decorating Ltd | Construction | 2023 |
| KLF Global Ltd | Administrative & support | 2023 |
| Klick Karz Ltd | Wholesale & retail | 2020 |
| Klickit Ltd | Wholesale & retail | 2019 |
| Klicknbuy Limited | Wholesale & retail | 2019 |
| Klien & Co. Limited | Administrative & support | 1995 |
| Klipa Ltd | Administrative & support | 2022 |
| Klozey Limited | Wholesale & retail | 2023 |
| KLR Shopfronts Ltd | Construction | 2020 |
| KLS Group Ltd | Construction | 2015 |
| KLS Tax & Accounting Limited | Professional & scientific | 2021 |
| Klyvora Limited | Wholesale & retail | 2026 |
| KM City Chauffeurs Ltd | Transport & logistics | 2015 |
| KM Driving School Ltd | Education | 2024 |
| KM Housing Consultancy Ltd | Professional & scientific | 2019 |
| KM Service Providers Ltd | Health & social care | 2024 |
| KM Traders Ltd | Wholesale & retail | 2016 |
| KMB Management Ltd | Real estate | 2025 |
| Kmch Holding Limited | Real estate | 2026 |
| Kmch Property Limited | Real estate | 2026 |
| Kmdefour Limited | Health & social care | 2025 |
| KMH Cars Ltd | Wholesale & retail | 2019 |
| Kmml Ltd | Construction | 2025 |
| Kmns Trading Ltd | Hospitality | 2016 |
| KMP Distributors Ltd | Wholesale & retail | 2026 |
| KMS & Partners Limited | Professional & scientific | 2008 |
| Kmtf Trade Limited | Wholesale & retail | 2025 |
| Kmughal Solutions Limited | Information & communication | 2016 |
| Knacktraders Limited | Wholesale & retail | 2018 |
| Knect Tech (UK) Ltd | Information & communication | 2019 |
| Kngpharm Limited | Other services | 2026 |
| Knight 24 Security Limited | Administrative & support | 2025 |
| Knight Assets (UK) Ltd | Real estate | 2015 |
| Knight Cooper Limited | Financial services | 2022 |
| Knighthood & Co Limited | Administrative & support | 2008 |
| Knighton Law Ltd | Professional & scientific | 2021 |
| Knighton London Ltd | Construction | 2018 |
| Knighton Property Investments Limited | Construction | 2020 |
| Knights Tandoori Caterers Ltd | Hospitality | 2026 |
| Knightsbridge EA Ltd | Real estate | 2015 |
| Knightsbridge Tailors 1 Limited | Other services | 2018 |
| Knightsworth Property Limited | Real estate | 2022 |
| KNK Builder Ltd | Construction | 2020 |
| KNK Properties Investment Ltd | Real estate | 2023 |
| Knoll Estates Limited | Real estate | 2019 |
| Knowledge Brew Ltd | Information & communication | 2025 |
| Knowledge Nest Ltd | Education | 2020 |
| Knowledge Transfer Ltd | Information & communication | 2022 |
| Knowledgems Global Ltd | Education | 2013 |
| Knox Creative Ltd | Arts & recreation | 2020 |
| Knox Entertainment Ltd | Administrative & support | 2013 |
| Knox Limited | Administrative & support | 2004 |
| Knox Projects Ltd | Construction | 2019 |
| KNR Car Rentals Ltd | Administrative & support | 2026 |
| Knuckleship Ltd | Administrative & support | 2020 |
| KNV Styling Ltd | Wholesale & retail | 2024 |
| KO Birth Method Limited | Health & social care | 2022 |
| KO London Property Ltd | Real estate | 2022 |
| Kocsis Services Limited | Transport & logistics | 2013 |
| Koda Retail Group Ltd | Wholesale & retail | 2026 |
| Kode Compliance Ltd | Professional & scientific | 2010 |
| Koded Solutions Ltd | Information & communication | 2014 |
| Kofi Coleman - Editor Ltd | Information & communication | 2023 |
| Kohinoor One Limited | Other services | 2022 |
| Kojones Limited | Professional & scientific | 2007 |
| Kokito Ltd | Construction | 2018 |
| Koklo Ltd | Hospitality | 2024 |
| Koko Juices Ltd | Manufacturing | 2025 |
| Kokozoki Ltd | Wholesale & retail | 2021 |
| Kolachi Street Food Ltd | Hospitality | 2025 |
| Kolev Construction Limited | Construction | 2024 |
| Kolip Traders Ltd | Wholesale & retail | 2019 |
| Kollanyi Capital Ltd | Financial services | 2024 |
| Kollun Ltd. | Education | 2002 |
| Kolpo Ltd | Professional & scientific | 2025 |
| Kombatx Limited | Wholesale & retail | 2025 |
| Kome Express Ilford Ltd | Hospitality | 2022 |
| Kompas Group Ltd | Administrative & support | 2024 |
| Kompas London Ltd | Administrative & support | 2016 |
| Kompashomes Ltd | Real estate | 2011 |
| Koni Vision Limited | Construction | 2025 |
| Konsept Homes Limited | Households | 2022 |
| Konstantinos Saragoudas Ltd | Real estate | 2024 |
| Koolab Ltd | Professional & scientific | 2024 |
| Koolfi Club Ltd | Information & communication | 2020 |
| Kord Security Ltd | Construction | 2024 |
| Korea Culture Group Ltd | Administrative & support | 2026 |
| Kornel East London Apartment Ltd | Hospitality | 2025 |
| Kornerbloc UK Limited | Construction | 2021 |
| Koroma's Kitchen Limited | Hospitality | 2025 |
| Koros Press Limited | Wholesale & retail | 2010 |
| Korotana Group Ltd | Real estate | 2021 |
| Korvex Auto Ltd | Wholesale & retail | 2026 |
| Korvex Security Limited | Administrative & support | 2026 |
| Korvia Ltd | Wholesale & retail | 2025 |
| Kosher Events Ltd | Administrative & support | 2009 |
| KOT Properties Ltd | Real estate | 2023 |
| Kothapally Solutions Limited | Information & communication | 2014 |
| Kotorri Construction & Maintenance Ltd | Construction | 2021 |
| Kotsevski Ltd | Other services | 2024 |