| Jacksons Services Limited | Wholesale & retail | 2006 |
| Jack`S Cafe & Bar Ltd | Hospitality | 2010 |
| Jack’D N Loaded Ltd | Hospitality | 2025 |
| Jacme Oral Care Limited | Health & social care | 2006 |
| Jaco-Sumal Limited | Manufacturing | 1957 |
| Jacob Lance Limited | Wholesale & retail | 2010 |
| Jacob Little Homes Ltd | Hospitality | 2025 |
| Jacob Manning Ltd | Wholesale & retail | 2024 |
| Jacob Traders Ltd | Wholesale & retail | 2022 |
| Jacobs & Co Properties Limited | Real estate | 2024 |
| Jacobs & Jacobs Wills & Estate Planners Limited | Professional & scientific | 2019 |
| Jacobs & SON (Butchers) Limited | Wholesale & retail | 2003 |
| Jacobs Law Solicitors Ltd | Professional & scientific | 2013 |
| Jacobs Real Estate Limited | Real estate | 2021 |
| Jacobs Services Ltd | Health & social care | 2023 |
| Jacobus Media Ltd | Professional & scientific | 2020 |
| Jacoby Place HL Ltd | Real estate | 2018 |
| Jacole Home Ltd | Administrative & support | 2024 |
| Jacovou Ltd | Extraterritorial | 2014 |
| Jacqueline Finnegan Limited | Education | 2018 |
| Jacqui Limited | Administrative & support | 2023 |
| Jacs (Midlands) Chippy Limited | Hospitality | 2025 |
| Jacs (Midlands) Ltd | Hospitality | 2012 |
| Jacs (Midlands) Trailer Limited | Hospitality | 2025 |
| Jact Properties Ltd | Real estate | 2024 |
| Jacynth Ivey Global Ltd | Professional & scientific | 2020 |
| JAD Autos Ltd | Wholesale & retail | 2023 |
| JAD Clearence Ltd | Wholesale & retail | 2025 |
| JAD Motor Ltd | Wholesale & retail | 2019 |
| JAD Network Technology Ltd | Information & communication | 2023 |
| Jadat Limited | Real estate | 2023 |
| Jaddoc Ltd | Administrative & support | 2018 |
| Jade Associates (Medical) Ltd | Health & social care | 2010 |
| Jade Commercial Laundry Services Limited | Other services | 2021 |
| Jade Education Limited | Education | 2020 |
| Jade Garden (Coventry) Ltd | Hospitality | 2021 |
| Jade Garden (Perry Barr) Ltd | Hospitality | 2026 |
| Jade Garden 118 Ltd | Hospitality | 2019 |
| Jade Garden 168 Ltd | Hospitality | 2026 |
| Jade Garden 328 Limited | Hospitality | 2022 |
| Jade Garden T2 Ltd | Hospitality | 2024 |
| Jade Gate Ltd | Real estate | 2020 |
| Jade Housing Services Ltd | Construction | 2023 |
| Jade Payroll & Accounting Services Ltd | Professional & scientific | 2020 |
| Jade Rainbow Food Ltd | Wholesale & retail | 2024 |
| Jaded Ltd | Wholesale & retail | 2022 |
| Jademaster Limited | Other services | 2023 |
| Jadestone Developers Ltd | Construction | 2024 |
| Jadewood Consultants Limited | Information & communication | 2004 |
| Jadex Consulting Limited | Professional & scientific | 2023 |
| Jadlyn Ltd | Health & social care | 2018 |
| Jadonlabs Ltd | Information & communication | 2025 |
| Jadoon Trading & Co Limited | Wholesale & retail | 2016 |
| JAE IM KIM Ltd | Wholesale & retail | 2019 |
| Jaeds Holdings Ltd | Financial services | 2025 |
| Jaeger Enterprises Limited | Administrative & support | 2009 |
| Jaena Limited | Extraterritorial | 2012 |
| Jaeran Capital Ltd | Real estate | 2023 |
| Jaesh Limited | Wholesale & retail | 2013 |
| Jafa Services Limited | Professional & scientific | 2023 |
| Jafaria Educational Trust | Other services | 2016 |
| Jaffal Coffee Ltd | Manufacturing | 2024 |
| Jaffer Accountancy Ltd | Professional & scientific | 2014 |
| Jaffer Consultancy Ltd | Health & social care | 2024 |
| Jaffer Trading Limited | Financial services | 2021 |
| Jaffery Optical Limited | Health & social care | 2008 |
| Jaffna Stores Ltd | Wholesale & retail | 2018 |
| Jaffray Care Society | Health & social care | 1990 |
| Jaffray Property Solutions | Real estate | 2010 |
| Jaffrey Enterprises UK Limited | Administrative & support | 2013 |
| Jafrc Ltd | Health & social care | 2022 |
| JAG Courier Services Limited | Transport & logistics | 2015 |
| JAG Couture+ Limited | Construction | 2026 |
| JAG Market Research Ltd | Other services | 2012 |
| Jaga LUX Ltd | Wholesale & retail | 2015 |
| Jagannatha DAS Ltd | Education | 2025 |
| Jagdev Legal Limited | Professional & scientific | 2007 |
| Jagfateh Transport Ltd | Transport & logistics | 2023 |
| Jagga Jatt Creations Ltd | Information & communication | 2020 |
| Jaggers Traffic Management Ltd | Administrative & support | 2015 |
| Jagjay Ltd | Health & social care | 2023 |
| Jagjit Transport Company Limited | Transport & logistics | 2025 |
| Jagmr Holdings Limited | Financial services | 2025 |
| Jago Publishing Limited | Administrative & support | 2010 |
| Jagsun Holdings Ltd | Financial services | 2022 |
| Jagsun Ltd | Construction | 2022 |
| Jagtar Services Limited | Real estate | 2016 |
| Jagtechnik Limited | Extraterritorial | 2008 |
| Jagtex Ltd | Wholesale & retail | 2026 |
| Jaguar Aerodynamics Ltd | Information & communication | 2023 |
| Jaguar Capital Ltd | Other services | 2024 |
| Jagwinder Couriers Ltd | Transport & logistics | 2026 |
| Jagwinder Singh Ltd | Construction | 2024 |
| Jagz Dhaliwal Limited | Transport & logistics | 2018 |
| JAH JAH Solutions Ltd | Administrative & support | 2025 |
| Jaha Limited | Real estate | 2025 |
| Jahan Capital Limited | Real estate | 2022 |
| Jahan Tech Solutions Ltd | Information & communication | 2023 |
| Jahangeer Enterprises Ltd | Wholesale & retail | 2024 |
| Jahania Halal Food Ltd | Wholesale & retail | 2017 |