| Kixx Burnley Ltd | Education | 2024 |
| Kiyah Consultancy Ltd | Professional & scientific | 2025 |
| Kizuna Recruitment Limited | Administrative & support | 2024 |
| KJ Ltd | Wholesale & retail | 2024 |
| KJI Garden Services Limited | Administrative & support | 2014 |
| KJI Services Ltd | Administrative & support | 2026 |
| KK Commercial Limited | Real estate | 2015 |
| KK Precision Imaging Private Ltd | Health & social care | 2026 |
| Kkaurpharma Limited | Wholesale & retail | 2019 |
| Kksandhu Ltd | Professional & scientific | 2024 |
| Kksandhu Property Ltd | Real estate | 2024 |
| Klassy K9 Limited | Wholesale & retail | 2021 |
| KLB Construction Limited | Construction | 2010 |
| KLH Maintenance Ltd | Manufacturing | 2021 |
| Klik & Delivered Limited | Other services | 2025 |
| Klik E-Commerce Limited | Other services | 2025 |
| Klik Market Limited | Other services | 2025 |
| Klikkart Limited | Other services | 2025 |
| Klmc GP Ltd | Health & social care | 2018 |
| Kluber Lubrication Great Britain Limited | Manufacturing | 1972 |
| KM Global Boutique Ltd | Wholesale & retail | 2025 |
| KM Systems Engineering Ltd | Professional & scientific | 2022 |
| KMB Storage Ltd | Other services | 2017 |
| KMC Research Limited | Professional & scientific | 2019 |
| KMK Removal & Shipping Ltd | Transport & logistics | 2020 |
| Kmountain Ltd | Professional & scientific | 2022 |
| Knight 247 Travels Ltd | Transport & logistics | 2022 |
| Knightsbridge Furniture Ltd | Manufacturing | 2021 |
| Knightstone Ltd | Construction | 2024 |
| Knightstone Properties North Limited | Real estate | 2025 |
| Knitting & Crochet Guild | Other services | 2005 |
| Knockout Vision Ltd | Information & communication | 2022 |
| Knowing My Game Ltd | Professional & scientific | 2025 |
| Knowl Court Flat Management Limited | Households | 1987 |
| Knowle Practice Ltd | Health & social care | 2024 |
| Knowledge Tree Centre | Other services | 2025 |
| Knuckle Sandwich Ltd | Professional & scientific | 2024 |
| Knuckle UP Ltd | Wholesale & retail | 2022 |
| Koba K9 Academy Ltd | Agriculture & fishing | 2022 |
| Kobane Grill Ltd | Hospitality | 2025 |
| Kobane Holding Ltd | Real estate | 2020 |
| Kodirect Store Limited | Wholesale & retail | 2023 |
| Kohli Co Properties Ltd | Real estate | 2024 |
| Kohli Co UK Limited | Construction | 2009 |
| Koji Health Ltd | Wholesale & retail | 2024 |
| Kolbus Investment Ltd | Financial services | 2022 |
| Kollet Limited | Wholesale & retail | 2025 |
| Kolor-Seal Limited | Construction | 2004 |
| Komfi Solutions Ltd | Information & communication | 2016 |
| Komfy Living Limited | Wholesale & retail | 2018 |
| KONNECT4U Ltd | Construction | 2021 |
| Kooms and Calloway Ltd | Hospitality | 2020 |
| Korstone Limited | Administrative & support | 2026 |
| Kosmetiko Aesthetic Clinic Limited | Health & social care | 2017 |
| Kosmetiko Training Academy Limited | Other services | 2021 |
| Kouturebyajike Ltd | Manufacturing | 2025 |
| KP Kitchen Design Ltd | Other services | 2025 |
| KPD Events Ltd | Manufacturing | 2022 |
| KPR Maintenance Ltd | Construction | 2025 |
| KPT 798 Ltd | Hospitality | 2025 |
| Kr&Em Ltd | Real estate | 2023 |
| Kracht Ltd | Wholesale & retail | 2023 |
| Krafty Beggars Ltd | Wholesale & retail | 2021 |
| Kratos Ltd | Wholesale & retail | 2017 |
| Krave Desserts Huddersfield Ltd | Hospitality | 2024 |
| Kreative Displays Ltd | Professional & scientific | 2016 |
| Kris Taylor Ltd | Professional & scientific | 2021 |
| Kristal Ltd | Professional & scientific | 2024 |
| Krsa Ltd | Professional & scientific | 2025 |
| Kruger's Engineering Ltd | Manufacturing | 2020 |
| Krylon UK Limited | Arts & recreation | 2013 |
| Krystallklear Ltd. | Administrative & support | 2025 |
| KS Bespoke Builds Limited | Construction | 2025 |
| KS HUD (Freehold) Ltd | Real estate | 2025 |
| KS HUD Ltd | Real estate | 2025 |
| KS Joinery & Construction Ltd | Manufacturing | 2018 |
| KS Project Solutions Ltd | Construction | 2026 |
| KS14 Limited | Real estate | 2022 |
| KSA & Sons Construction Ltd | Real estate | 2021 |
| KSA Managment Consultancy Ltd | Professional & scientific | 2025 |
| Ksdl Land Limited | Arts & recreation | 2016 |
| Ksmart Enterprises Limited | Information & communication | 2025 |
| Kspg Property Ltd | Real estate | 2021 |
| KSR Signs Ltd | Manufacturing | 2025 |
| Ksuk Traders Limited | Wholesale & retail | 2025 |
| Ktlex Ltd | Professional & scientific | 2025 |
| KTM Distributions Ltd | Wholesale & retail | 2025 |
| Ktrump Ltd | Wholesale & retail | 2023 |
| KUK Buddy Ltd | Manufacturing | 2025 |
| Kukson Solutions Limited | Wholesale & retail | 2025 |
| Kurdistan HUD Ltd | Other services | 2024 |
| Kurt Abbas Food Ltd | Hospitality | 2026 |
| Kuvs Corporation Ltd | Real estate | 2025 |
| Kvasir Digital Limited | Information & communication | 2020 |
| KW Develops Ltd | Real estate | 2025 |
| KWC Group Ltd | Administrative & support | 2019 |
| Kynd Minds Ltd | Education | 2026 |
| L & a Holdings (Yorkshire) Limited | Financial services | 2024 |
| L & K PUB Group Ltd | Hospitality | 2024 |
| L & R Holding Group Ltd | Extraterritorial | 2024 |