| K. a. London Property Limited | Real estate | 2017 |
| K. a. Southeast Property Limited | Real estate | 2019 |
| K.A. North West Property Limited | Real estate | 2021 |
| K.A. South West Property Limited | Real estate | 2019 |
| K.A. Sovereign Property Ltd | Real estate | 2022 |
| K.A.S. Precision Engineering Limited | Extraterritorial | 1993 |
| K.D.V. Electrical Services Ltd | Construction | 2016 |
| K.Greg Ltd | Construction | 2020 |
| K2 Rigging Ltd | Construction | 2024 |
| KA Fire Safety Solutions Ltd | Professional & scientific | 2026 |
| Kaaj Construction Limited | Construction | 2026 |
| Kababish Limited | Hospitality | 2015 |
| Kabongress (UK) Limited | Health & social care | 2019 |
| Kabul Fish House Ltd | Hospitality | 2026 |
| Kachistan Ltd | Real estate | 2023 |
| Kadisco General Waste Ltd | Wholesale & retail | 2023 |
| Kaghan Ltd | Wholesale & retail | 2026 |
| Kahoito Ltd | Health & social care | 2023 |
| KAL Construct Ltd | Construction | 2025 |
| Kang Real Estates Ltd | Real estate | 2023 |
| Kannan Builders Ltd | Construction | 2025 |
| Karibu Rwanda Ltd | Administrative & support | 2008 |
| Karish Foods Limited | Hospitality | 2017 |
| Karmline Limited | Health & social care | 2015 |
| Karo Food Ltd | Hospitality | 2023 |
| Karroll Enterprise Limited | Wholesale & retail | 2024 |
| Karwan J Properties Ltd | Real estate | 2024 |
| KAS Plumbing & GAS Ltd | Construction | 2021 |
| Kashi Global Limited | Administrative & support | 2011 |
| Kasias Karpets Limited | Manufacturing | 2012 |
| Katherine and Helen Court Limited | Households | 2019 |
| Katie Gibson Pilates Ltd | Arts & recreation | 2022 |
| Kaxton Advisory Ltd | Professional & scientific | 2011 |
| Kaxton Properties Ltd | Real estate | 2020 |
| Kaxton Research Ltd. | Information & communication | 2023 |
| Kayi Newborn Services Limited | Health & social care | 2012 |
| Kays International Limited | Real estate | 2024 |
| KBO Services Ltd | Professional & scientific | 2024 |
| Kcbe Group Ltd | Administrative & support | 2024 |
| Kdkd Ventures Ltd | Wholesale & retail | 2025 |
| Kedibonye Ltd | Administrative & support | 2022 |
| Keezy Corp Limited | Arts & recreation | 2026 |
| Kelaya Ltd | Other services | 2025 |
| KEN Plan Design & Build Ltd | Construction | 2019 |
| Kensington & Westminster Mortgages Limited | Financial services | 2018 |
| Kensington Chauffeurs Ltd | Transport & logistics | 2025 |
| Kent Auto Sales Limited | Wholesale & retail | 2014 |
| Kent Car Sales Limited | Wholesale & retail | 2025 |
| Kent Couriers Ltd | Transport & logistics | 2008 |
| Kenthouse Property Ltd | Real estate | 2015 |
| Kentiss Food UK Limited | Hospitality | 2019 |
| Kera Intelligence Ltd | Information & communication | 2026 |
| Kera Ltd | Wholesale & retail | 2026 |
| Keshari Ltd | Wholesale & retail | 2024 |
| Kevin Duggan Ltd | Professional & scientific | 2016 |
| Key Empire Resources (UK) Limited | Mining & quarrying | 2011 |
| Keyspace Housing Limited | Real estate | 2026 |
| Keystones Properties Ltd | Real estate | 2025 |
| Kfic | Financial services | 2020 |
| KG Construction & Solutions Limited | Construction | 2024 |
| Kg.Electrics London Limited | Construction | 2013 |
| KH Tech Ltd | Manufacturing | 2024 |
| Khalid Heights Ltd | Real estate | 2023 |
| Khan & Co Property Investments Ltd | Real estate | 2025 |
| Khan Capital Holdings Ltd | Real estate | 2025 |
| Khanam Zahra Ltd | Wholesale & retail | 2025 |
| Kharis Global Group Ltd | Professional & scientific | 2017 |
| Kiara Vision Limited | Wholesale & retail | 2024 |
| Kibatto High Care Limited | Wholesale & retail | 2020 |
| KID Smart Ltd | Education | 2018 |
| KIH Ltd | Wholesale & retail | 2023 |
| Kiki Excellent Services Ltd | Administrative & support | 2020 |
| Killoughery Construction Limited | Construction | 1990 |
| Killoughery Limited | Financial services | 2013 |
| Killoughery Waste Management Limited | Water & waste | 2001 |
| Kimia Cosmetics Ltd | Wholesale & retail | 2025 |
| Kinash (K1) Limited | Real estate | 2024 |
| Kinash House Ltd | Real estate | 2020 |
| Kingdom Success Limited | Financial services | 2025 |
| Kingfisher Vehicle Repair Limited | Wholesale & retail | 2021 |
| Kings of Gaana Limited | Arts & recreation | 2025 |
| Kingsley Assets South Ltd | Real estate | 2025 |
| Kingsley Sovereign Holdings Limited | Financial services | 2025 |
| Kingsley Tyres Limited | Wholesale & retail | 2026 |
| Kingston Bridge Ltd. | Transport & logistics | 2013 |
| Kingsway Scaffolding Ltd | Construction | 2025 |
| Kingsway Super Store (Luton) Limited | Wholesale & retail | 2013 |
| Kinwell Property Limited | Real estate | 2025 |
| Kirzan Limited | Information & communication | 2013 |
| Kishaan Thurai Ltd | Extraterritorial | 2025 |
| KIT & LK Limited | Real estate | 2021 |
| Kitchen Furniture Online Limited | Wholesale & retail | 2019 |
| Kitsco Limited | Education | 2011 |
| Kitsune Limited | Wholesale & retail | 2022 |
| Kiyara Trends Limited | Wholesale & retail | 2024 |
| KJN Construction Limited | Construction | 2025 |
| KK Apex Limited | Construction | 2025 |
| KK Importers Limited | Wholesale & retail | 2025 |
| KK Supermarket Limited | Wholesale & retail | 2023 |
| Kkccp Ltd | Professional & scientific | 2025 |