| KJ Property Developers Ltd | Real estate | 2020 |
| KJP Electrical Limited | Manufacturing | 2020 |
| KJP Financial Limited | Financial services | 2021 |
| KJS Construction and Developments Ltd | Construction | 2025 |
| KJW Plumbing Heating & GAS Ltd | Construction | 2023 |
| KK Newport Limited | Hospitality | 2023 |
| KLA Corporation UK Holdings Limited | Manufacturing | 2014 |
| KLA Corporation UK Limited | Manufacturing | 2009 |
| Klar HR Limited | Administrative & support | 2025 |
| Klass Consulting Ltd | Information & communication | 2022 |
| KLD Social Care Solutions Ltd | Health & social care | 2024 |
| Kleetus Ltd | Health & social care | 2023 |
| KM Barbers NPT Ltd | Other services | 2024 |
| KM Cabs Limited | Transport & logistics | 2025 |
| KMA Aesthetics Ltd | Other services | 2022 |
| KMK Property Services Ltd | Construction | 2025 |
| Kmps Projects Ltd | Manufacturing | 2023 |
| KN Property Developments Ltd | Real estate | 2019 |
| Knight Apps Limited | Information & communication | 2026 |
| Knights Electrical SW Ltd | Construction | 2024 |
| Knights Legal Services Limited | Administrative & support | 2011 |
| Knights Properties Limited | Real estate | 2012 |
| Knights Three Consultancy Limited | Real estate | 2016 |
| Knockour Farm Ltd | Agriculture & fishing | 2019 |
| Knpj Property Limited | Real estate | 2024 |
| Koac Ltd | Professional & scientific | 2020 |
| Kodzerai Limited | Health & social care | 2022 |
| Koko Indulge Ltd | Manufacturing | 2024 |
| Koko OIL Ltd | Water & waste | 2021 |
| Koloth Care Solutions Limited | Administrative & support | 2018 |
| Kolys Foods Ltd | Wholesale & retail | 2022 |
| Kolys Properties Limited | Real estate | 2026 |
| Komas Cutz Ltd | Other services | 2023 |
| Kore Gym Ltd | Arts & recreation | 2025 |
| Korky Cards Limited | Wholesale & retail | 2025 |
| Koskocan Ltd | Real estate | 2025 |
| Kotho Limited | Real estate | 2021 |
| Kotnat Ventures Ltd | Real estate | 2020 |
| Koum Therapies Ltd | Health & social care | 2025 |
| Kozo Trans Limited | Transport & logistics | 2025 |
| KPG Homes Ltd | Real estate | 2025 |
| Kraftii Ltd | Wholesale & retail | 2024 |
| Krest Consultancy Limited | Professional & scientific | 2025 |
| Kris KP Services Ltd | Construction | 2019 |
| KRK Solutions (UK) Ltd | Wholesale & retail | 2021 |
| KRK Translations Ltd | Professional & scientific | 2020 |
| KRO Transport Ltd | Transport & logistics | 2022 |
| KS Electro Mechanical Limited | Information & communication | 2019 |
| KSG 18 Trading Ltd | Hospitality | 2025 |
| KSG 9 Ltd | Real estate | 2024 |
| KSG Inspired Properties Ltd | Hospitality | 2022 |
| Kshairandstudios Ltd | Other services | 2025 |
| KSZ Taxis Ltd | Transport & logistics | 2020 |
| KTA Aviation Ltd | Manufacturing | 2025 |
| Kuberax Ltd | Professional & scientific | 2025 |
| Kudos Trading LLP | | 2024 |
| Kudosobi Limited | Health & social care | 2023 |
| Kufaka Ltd | Wholesale & retail | 2025 |
| Kukd.Com (UK) Ltd | Hospitality | 2018 |
| Kular 191D Ltd | Hospitality | 2024 |
| Kullar SPV 1 Limited | Real estate | 2024 |
| Kumaresa Ltd | Health & social care | 2021 |
| Kumon Foods Ltd | Hospitality | 2018 |
| Kuna Udayah Ltd | Wholesale & retail | 2024 |
| Kunduru Limited | Real estate | 2025 |
| Kupacare Ltd | Health & social care | 2024 |
| Kurd Barbers 3 Ltd | Other services | 2026 |
| Kurucz Logistics Ltd | Transport & logistics | 2019 |
| Kuzhagan Limited | Real estate | 2025 |
| KW (Newport) Limited | Hospitality | 2019 |
| Kwan Family Limited | Health & social care | 2022 |
| Kwan Yick (U.K.) Limited | Wholesale & retail | 1987 |
| KWF Builders Limited | Construction | 2023 |
| KWL 2023 EOT Limited | Professional & scientific | 2023 |
| KWL Architects Limited | Professional & scientific | 2005 |
| Kwtch Limited | Professional & scientific | 2011 |
| KYF Healthcare Ltd | Health & social care | 2025 |
| Kyle Nails & Beauty Ltd | Other services | 2024 |
| Kyles Transport Services Limited | Transport & logistics | 2003 |
| Kymin Wealth Limited | Financial services | 2012 |
| L & M Ventilation Limited | Construction | 2008 |
| L C Fibre Connections Limited | Information & communication | 2025 |
| L J Symonds Roofing Limited | Construction | 2023 |
| L M Property Investments Ltd | Real estate | 2007 |
| L Mustoe Limited | Real estate | 2015 |
| L Powell Upvc Ltd | Construction | 2023 |
| L R B Flooring Services Limited | Construction | 2017 |
| L R B Line Painting Ltd | Construction | 2022 |
| L S Barbers Ltd | Wholesale & retail | 2020 |
| L S Property (Shropshire) Limited | Real estate | 2018 |
| L Tolland Limited | Real estate | 2025 |
| L&C Mechanical Ltd | Wholesale & retail | 2025 |
| L&M Plus Consulting Limited | Professional & scientific | 2011 |
| L&M Rigging Services Ltd | Manufacturing | 2016 |
| L&M Tropical Ltd | Wholesale & retail | 2019 |
| L&S Buildings and Renovations Ltd | Construction | 2025 |
| L.Aston Welding Ltd | Construction | 2019 |
| L.Brodie Properties Ltd | Real estate | 2021 |
| L.C Welding Ltd | Construction | 2023 |
| L.C.M. Systems Limited | Manufacturing | 1986 |