| Jp.Peers Ltd | Arts & recreation | 2024 |
| JPB Construction Consultant Ltd | Administrative & support | 2016 |
| JPE Building Refurbishments Limited | Construction | 2020 |
| JPE Heating Limited | Construction | 2017 |
| Jpmsteels Limited | Construction | 2017 |
| JPN Digital Services Ltd | Information & communication | 2019 |
| Jpsa Ltd | Professional & scientific | 2024 |
| JRC Plumbing and Heating Ltd | Construction | 2025 |
| JRC Solutions Limited | Financial services | 2021 |
| JS Comics Ltd | Information & communication | 2020 |
| JS Stairlifts Ltd | Manufacturing | 2024 |
| JS& HL Co., Limited | Extraterritorial | 2017 |
| Jsgn Ltd | Wholesale & retail | 2024 |
| JSR Electrical Ltd | Construction | 2014 |
| JSR Limited | Other services | 2025 |
| JT Scaffolding Ltd | Construction | 2024 |
| Jtec Holdings Limited | Hospitality | 2024 |
| JTM Refrigeration Ltd | Manufacturing | 2022 |
| Jtrm Transport Ltd | Transport & logistics | 2019 |
| JTW Electrical Services Limited | Construction | 2020 |
| Jubilee Clips Limited | Manufacturing | 1977 |
| Judds Machinery Sales Limited | Manufacturing | 2011 |
| Juicy Drips Ltd | Health & social care | 2025 |
| Jujin Group Limited | Manufacturing | 2019 |
| Julian Clover Associates Ltd | Professional & scientific | 2023 |
| Julian Mincher Equestrian Limited | Wholesale & retail | 2015 |
| Jumai Jewel Limited | Extraterritorial | 2022 |
| Just Chill Cooling Ltd | Construction | 2023 |
| Just Corner Shop Ltd | Wholesale & retail | 2014 |
| Just SHY Media Ltd | Information & communication | 2025 |
| Just This Retail Ltd | Wholesale & retail | 2025 |
| JUSTALLIDEBS72 Limited | Health & social care | 2022 |
| Justwow Ltd | Agriculture & fishing | 2009 |
| JVP Cleaning Ltd | Administrative & support | 2025 |
| JVW Productions Ltd | Professional & scientific | 2017 |
| JW Access Solutions Ltd | Construction | 2025 |
| JW Financial Direction Ltd | Extraterritorial | 2016 |
| JZH Technical Ltd | Manufacturing | 2026 |
| K & B Builders (South West) Ltd | Construction | 2015 |
| K & C Steel Corporation Ltd | Manufacturing | 2024 |
| K & P Development & Building Limited | Construction | 2020 |
| K F Construction Services Ltd | Professional & scientific | 2021 |
| K Fixes Ltd | Construction | 2021 |
| K JEY Property Ltd | Real estate | 2022 |
| K R Concept Limited | Manufacturing | 2018 |
| K W C (UK) Limited | Wholesale & retail | 1990 |
| K W Nursery Ltd | Education | 2013 |
| K&G VIP Services Ltd | Wholesale & retail | 2017 |
| K&J Plumbing and Bathrooms Ltd | Construction | 2025 |
| K&K Tackle & Bait Ltd | Wholesale & retail | 2026 |
| K'Dam Project Ltd | Education | 2021 |
| K-Mathu Ltd | Hospitality | 2025 |
| K. C. Hotel Limited | Hospitality | 1976 |
| K.G. Property Limited | Construction | 2015 |
| K.M. Ersus Limited | Construction | 2019 |
| K1 Building Services Limited | Construction | 2022 |
| K3I Limited | Information & communication | 2020 |
| KA Accommodation Limited | Real estate | 2021 |
| Kadirs Commissioning Services Ltd | Professional & scientific | 2024 |
| Kael Art Limited | Arts & recreation | 2024 |
| Kaemotherapy Ltd | Other services | 2020 |
| Kaia Engineering Limited | Professional & scientific | 2019 |
| Kaimore Ltd | Professional & scientific | 2025 |
| Kainuote Steel Group Co., Ltd | Manufacturing | 2024 |
| Kairo Distributors Ltd | Other services | 2025 |
| Kairo Dolce Ltd | Manufacturing | 2026 |
| Kairo&Co Ltd | Hospitality | 2025 |
| Kaiser BJJ Ltd | Arts & recreation | 2020 |
| Kaka International Ltd | Wholesale & retail | 2022 |
| Kalistrin Ltd | Transport & logistics | 2020 |
| Kallah & Co Limited | Professional & scientific | 2021 |
| Kamblu Global Ltd | Health & social care | 2022 |
| Kami K Services Limited | Transport & logistics | 2025 |
| KAN Fish Bar Ltd | Hospitality | 2025 |
| Kana Builders Ltd | Construction | 2025 |
| Kandel Homes Ltd | Real estate | 2025 |
| Kandy Uppal Property Ltd | Real estate | 2025 |
| Kannan Properties Ltd | Real estate | 2007 |
| Kaoan UK Ltd | Hospitality | 2025 |
| Kapisa Limited | Wholesale & retail | 2017 |
| Karate Leadership UK Limited | Arts & recreation | 2007 |
| Karebear Day Boarding Ltd | Other services | 2023 |
| Karmau Ltd | Arts & recreation | 2024 |
| Karzi Amina Ltd | Other services | 2020 |
| Kaya Electric Ltd | Construction | 2026 |
| Kaya Property Holding Limited | Real estate | 2018 |
| Kayes Electrical (Kent) Ltd. | Manufacturing | 2000 |
| Kayfield Corporation Ltd | Information & communication | 2025 |
| Kaygold Ltd | Manufacturing | 2025 |
| Kayode Holdings Limited | Real estate | 2020 |
| Kaytan Services Ltd | Health & social care | 2023 |
| Kayton Hill Ltd | Public administration | 2024 |
| KBF Futures Consulting Ltd | Information & communication | 2016 |
| KBM Services (Kent) Limited | Construction | 2022 |
| Kbsoft Limited | Information & communication | 2021 |
| KD Drainage and Asbestos Ltd | Other services | 2019 |
| KDL I1 Limited | Financial services | 2022 |
| KDL I2 Limited | Financial services | 2022 |
| Kdtraffic Ltd | Construction | 2018 |
| KE Assets Limited | Households | 2022 |