| Jedi-Robe.Com Limited | Manufacturing | 2008 |
| Jepsa Limited | Manufacturing | 2020 |
| Jerix Ltd | Other services | 2024 |
| Jessica Collection Ltd | Wholesale & retail | 2026 |
| Jestco Ltd | Wholesale & retail | 2004 |
| JET SET Group Limited | Transport & logistics | 2025 |
| Jet's Property Services Ltd | Construction | 2012 |
| Jeya Salon Ltd | Other services | 2026 |
| Jeyakumaran Limited | Wholesale & retail | 2023 |
| JF LUX Autos Limited | Wholesale & retail | 2026 |
| JH London Ltd | Transport & logistics | 2018 |
| Jihan Constructions Ltd | Construction | 2026 |
| JJ Empire Ltd | Other services | 2020 |
| JJ Singh Estates Limited | Real estate | 2025 |
| Jjcavanna Limited | Real estate | 2021 |
| JK & Sons Ltd | Wholesale & retail | 2006 |
| JK Design & Build Limited | Construction | 2013 |
| Jkkk Retail Ltd | Wholesale & retail | 2025 |
| JKS Heating Ltd | Construction | 2020 |
| JLR London Limited | Construction | 2018 |
| JM Newport Limited | Other services | 2010 |
| JMC Carpentry & Building Specialists Limited | Construction | 2016 |
| Jmkd Construction Ltd | Construction | 2023 |
| JNJ Finance Ltd | Financial services | 2022 |
| JOE Debs Services Ltd | Health & social care | 2025 |
| Joedebs Limited | Health & social care | 2018 |
| Joejek Ltd | Administrative & support | 2017 |
| John MAY & Sons Ltd | Construction | 2011 |
| Jonesygains Ltd | Arts & recreation | 2020 |
| Jonstone Limited | Construction | 2017 |
| Joseph & Father Building Works Ltd | Wholesale & retail | 2025 |
| Joshi ERP Solutions Ltd. | Information & communication | 2014 |
| Joudia Ltd | Wholesale & retail | 2025 |
| Journal My Journey Community C.I.C. | Education | 2026 |
| Journal My Journey Ltd | Wholesale & retail | 2022 |
| JP Community Consultancy Ltd | Professional & scientific | 2026 |
| JP West Construction Limited | Construction | 2013 |
| Jpco Limited | Manufacturing | 2010 |
| JPI Mortgages Ltd | Financial services | 2025 |
| JPP Estates Ltd | Real estate | 2024 |
| JPW Enterprises Ltd | Wholesale & retail | 2024 |
| JR 4 Construction Ltd | Construction | 2022 |
| JR360 UK Ltd | Real estate | 2025 |
| JSC Prestige Estate Limited | Real estate | 2025 |
| Jubiter Ltd | Wholesale & retail | 2020 |
| Jugune Limited | Real estate | 2011 |
| Julmar Ltd | Administrative & support | 2023 |
| Jurijus Dede Services Ltd | Construction | 2022 |
| Juriy Construction Limited | Construction | 2023 |
| JUS Vend IT Ltd | Hospitality | 2025 |
| Just Food 4 U Ltd | Hospitality | 2016 |
| Justin Construction Ltd | Construction | 2009 |
| Justlightsabers Ltd | Manufacturing | 2022 |
| JVG Consultants (UK) Limited | Professional & scientific | 2014 |
| JW Property Wealth Limited | Real estate | 2021 |
| K & LI Limited | Hospitality | 2016 |
| K Kwon DO Ltd | Education | 2026 |
| K R Logistic Services Limited | Transport & logistics | 2017 |
| K Shah Consultancy Services Limited | Professional & scientific | 2014 |
| K&Dt Properties Ltd | Real estate | 2018 |
| K&J Automotive Cars Repair Ltd | Wholesale & retail | 2026 |
| K'S Cocktails Ltd | Wholesale & retail | 2021 |
| K3 Extra Ltd | Other services | 2014 |
| Kaboora Ltd | Health & social care | 2013 |
| Kacko Ltd | Administrative & support | 2012 |
| Kadel Electrical Company Limited | Construction | 2000 |
| Kadem Software Services Ltd | Information & communication | 2023 |
| Kaif Global Trading Ltd | Wholesale & retail | 2026 |
| Kalian Ltd | Hospitality | 2023 |
| Kalkan Property Ltd | Extraterritorial | 2023 |
| Kalsi Developments Ltd | Transport & logistics | 2023 |
| Kalsi Holdings Group Ltd | Real estate | 2023 |
| Kalsi Investment Group Ltd | Financial services | 2026 |
| Kalsi Living Ltd | Real estate | 2026 |
| Kamber Car Wash Limited | Administrative & support | 2025 |
| Kandy Residencies Limited | Real estate | 2021 |
| Kaniki Ltd | Wholesale & retail | 2023 |
| KAP Collections Ltd | Wholesale & retail | 2024 |
| Kapada Properties Ltd | Real estate | 2019 |
| Karan Parmar Limited | Construction | 2024 |
| Karan Transport Ltd | Transport & logistics | 2025 |
| Kargo Konnect Ltd | Wholesale & retail | 2026 |
| Karna&Yam Ltd | Transport & logistics | 2021 |
| KAS Construction London Ltd | Administrative & support | 2017 |
| Kaselo Foods Limited | Hospitality | 2023 |
| Katherine Beauty Lounge Ltd | Other services | 2025 |
| Katra Consulting Ltd. | Professional & scientific | 2023 |
| Kaushika Entertainment Limited | Arts & recreation | 2025 |
| Kavyashvi Ltd | Hospitality | 2024 |
| Kazim Builder Services Limited | Construction | 2015 |
| KB & Chen Properties Ltd | Real estate | 2025 |
| KB Food Services Limited | Wholesale & retail | 2015 |
| Keatings Premium Care Companions Limited | Health & social care | 2026 |
| Kedah Limited | Wholesale & retail | 2020 |
| Keem Foods Limited | Hospitality | 2025 |
| Keen Build Ltd | Construction | 2016 |
| Keeyakrish Investment Limited | Real estate | 2020 |
| Kelly Trim Systems Ltd | Other services | 2004 |
| Kelsonoah Limited | Households | 2024 |
| Kemer Electrical Services Limited | Construction | 2014 |