| JK Best Solutions Ltd | Wholesale & retail | 2021 |
| JK Chandra Ltd | Information & communication | 2026 |
| JK Home Investments Ltd | Real estate | 2025 |
| Jkln Ltd | Health & social care | 2019 |
| JKM Transport Ltd | Transport & logistics | 2020 |
| JKS Property Rental Ltd | Real estate | 2023 |
| JL Spine Limited | Health & social care | 2026 |
| JL Super Pizza Ltd | Hospitality | 2024 |
| JLB Developments Limited | Real estate | 2021 |
| JLC Media & Marketing Ltd | Professional & scientific | 2025 |
| JLG Financial Services Ltd | Financial services | 2017 |
| JLM Investiments Ltd | Real estate | 2024 |
| JLM Recruitment Ltd | Administrative & support | 2013 |
| Jlon Ltd | Wholesale & retail | 2023 |
| Jlsfc Services Limited | Other services | 2021 |
| JLW IT Consultancy Ltd | Information & communication | 2026 |
| JM Rope Access Ltd | Construction | 2025 |
| JMB Livestock Limited | Wholesale & retail | 2025 |
| JMC Creative Direction Ltd | Other services | 2022 |
| JMK360 Limited | Professional & scientific | 2022 |
| JO Ellis Ltd | Health & social care | 2024 |
| Jobbet Ltd | Real estate | 2021 |
| Joepapi Limited | Health & social care | 2025 |
| John Beckly Limited | Health & social care | 2016 |
| John Coopers Leisure Limited | Wholesale & retail | 2018 |
| John Jackson & Sons Limited | Administrative & support | 1999 |
| John Quarmby & SON Limited | Extraterritorial | 1906 |
| John Yates Systems Limited | Professional & scientific | 2004 |
| Johnson Design Solutions Ltd | Professional & scientific | 2025 |
| Johnson Holdings Ltd | Financial services | 2023 |
| Johnson Strategic Investments Ltd | Financial services | 2026 |
| Johnston Medical Limited | Health & social care | 2023 |
| Jolly Gamekeeper Supplies Limited | Agriculture & fishing | 2022 |
| Jooles Clarke Aesthetics Limited | Other services | 2026 |
| Jordan Hind Ltd | Hospitality | 2024 |
| Joseph Black & Son,Limited | Agriculture & fishing | 1951 |
| Josh Jelly Limited | Other services | 2013 |
| Jourdan Medical Limited | Health & social care | 2010 |
| JP Distribution Limited | Wholesale & retail | 2026 |
| JP London Anaesthesia Limited | Health & social care | 2022 |
| Jphd Properties Ltd | Real estate | 2025 |
| JPO Automotive Ltd | Wholesale & retail | 2023 |
| JPR Digital Ltd | Professional & scientific | 2020 |
| Jprx Consulting Limited | Health & social care | 2016 |
| JPS Special Projects Ltd | Construction | 2020 |
| JQ Entertainment Limited | Other services | 2014 |
| JRG Mobile Services Limited | Wholesale & retail | 2019 |
| JS Recovery Ltd | Wholesale & retail | 2019 |
| JSG Automotive Ltd | Other services | 2017 |
| Jslse Limited | Real estate | 2021 |
| JSR Pipework Ltd | Construction | 2024 |
| JSV Motors Ltd | Wholesale & retail | 2025 |
| JT Lado Consultant Ltd | Health & social care | 2024 |
| JT Tubs Ltd | Manufacturing | 2026 |
| JTB Maintenance Ltd | Manufacturing | 2026 |
| JTF Holdings Limited | Financial services | 2023 |
| JTM Electrical (Lincolnshire) Limited | Manufacturing | 2020 |
| JU Transport Services Ltd | Transport & logistics | 2026 |
| Jubraj Ltd | Hospitality | 2015 |
| JUJ Servicing & Repairs Limited | Wholesale & retail | 2015 |
| Julia Raftery Consulting Limited | Professional & scientific | 2004 |
| Julie Properties Limited | Real estate | 2024 |
| Jungle Jim's Vivariums Ltd | Wholesale & retail | 2021 |
| Jura Developments Ltd | Real estate | 2023 |
| Jurassic Fossils Ltd | Wholesale & retail | 2017 |
| Juzdar Limited | Transport & logistics | 2018 |
| JW Accounting Management Limited | Professional & scientific | 2012 |
| JW Body Art Limited | Other services | 2026 |
| JW Medical Management Ltd | Professional & scientific | 2020 |
| JWH Property Rental Ltd | Real estate | 2020 |
| JZ Living Spaces Ltd | Real estate | 2025 |
| K B S (Scunthorpe) Ltd | Real estate | 2011 |
| K Beale Properties Limited | Real estate | 2024 |
| K Boat Properties Ltd | Real estate | 2023 |
| K Crowder Electrical Ltd | Construction | 2009 |
| K M Valeters Ltd. | Other services | 2002 |
| K Rescue N Recovery Ltd | Wholesale & retail | 2025 |
| K Sodhi Sonography Ltd | Health & social care | 2023 |
| K W Bassindale Limited | Construction | 2005 |
| K&K Team Ltd | Wholesale & retail | 2022 |
| K&S Savage Motors Ltd | Wholesale & retail | 2023 |
| K.B. Dale Limited | Wholesale & retail | 1991 |
| K.Beale Electrical Limited | Construction | 2021 |
| K.Finley Upvc Limited | Construction | 2025 |
| K.S Auto Export Ltd | Wholesale & retail | 2023 |
| K9-PARK Ltd | Arts & recreation | 2023 |
| Kadim Ltd | Hospitality | 2026 |
| Kadu Limited | Real estate | 2017 |
| Kadz Florals Ltd | Wholesale & retail | 2025 |
| Kahf Limited | Real estate | 2016 |
| Kaila Developments Limited | Real estate | 2020 |
| Kairadel Limited | Transport & logistics | 2023 |
| Kalkstein Limited | Transport & logistics | 2003 |
| Kalm Massage & Wellbeing Ltd | Other services | 2024 |
| Kamarin Computer Systems Limited | Information & communication | 1980 |
| Kamran Javed Ltd | Real estate | 2024 |
| Kapil Care Homes Limited | Health & social care | 1985 |
| Kass Bathroom Products Limited | Real estate | 2005 |
| Kathir Ltd | Manufacturing | 2024 |
| Kathy Chambers Ltd | Professional & scientific | 2024 |