| Jestin Anabelle Services Limited | Administrative & support | 2022 |
| Jestt Ltd | Financial services | 2026 |
| Jesus Celebration Centre International Ltd | Health & social care | 2015 |
| Jesus Celebration Ministries Limited | Other services | 2002 |
| Jesus Christ Belivereth Gospel - Preaching Ministry CIC | Other services | 2016 |
| JET Clear Cleaning Services Ltd | Administrative & support | 2019 |
| JET Limited | Other services | 1987 |
| Jetworld Travel Limited | Administrative & support | 1998 |
| Jevitts Consultancy Limited | Professional & scientific | 2025 |
| Jevitts Ltd | Real estate | 2022 |
| Jewel Agent UK Limited | Manufacturing | 2013 |
| Jewel Healthcare Solutions Ltd | Health & social care | 2026 |
| Jewell Inns Ltd | Hospitality | 2019 |
| JF Communications Limited | Information & communication | 2025 |
| JF Recruitment Limited | Administrative & support | 2023 |
| JFK Healthcare Limited | Health & social care | 2022 |
| JFL Broaches & Broaching Limited | Manufacturing | 2009 |
| Jfna Group Ltd | Wholesale & retail | 2025 |
| Jfnt Services Limited | Financial services | 2016 |
| JFS City Takeaway Ltd | Hospitality | 2018 |
| JFS Home Security Ltd | Administrative & support | 2024 |
| JG and HG Nellis Consultants Limited | Professional & scientific | 2014 |
| JG Healthcare Ltd | Health & social care | 2024 |
| JG Logika Consulting Ltd | Information & communication | 2016 |
| JG Media Services Ltd | Information & communication | 2009 |
| JG Sourced Ltd | Wholesale & retail | 2023 |
| JGH Origin Limited | Construction | 2012 |
| Jgji UK Financial Limited | Professional & scientific | 2018 |
| JGP MK Limited | Professional & scientific | 2015 |
| JGS Management Services Limited | Professional & scientific | 2019 |
| JGS Steel Fabricators Limited | Manufacturing | 2024 |
| Jgsa Ltd | Real estate | 2026 |
| JH Construction and Civils Ltd | Construction | 2025 |
| JH GAS Ltd | Construction | 2024 |
| JH Property Solutions Limited | Construction | 2012 |
| JHA Tech Limited | Health & social care | 2020 |
| Jhambs Driving School Ltd | Transport & logistics | 2023 |
| Jhambs Ltd | Wholesale & retail | 2020 |
| Jhcp Limited | Administrative & support | 2010 |
| JHE Property Developments Ltd | Real estate | 2017 |
| JHE Property Investements Ltd | Real estate | 2026 |
| JHG Limited | Information & communication | 2022 |
| JHG Property Management Ltd | Real estate | 2025 |
| Jhmusic Ltd | Arts & recreation | 2021 |
| Jhwe Ltd | Professional & scientific | 2024 |
| JHZ Eats Ltd | Hospitality | 2023 |
| JIA Heng Ltd. | Wholesale & retail | 2025 |
| JIA Jian Chen Ltd. | Wholesale & retail | 2025 |
| JIA LIN Jiang Ltd. | Wholesale & retail | 2025 |
| Jian CAI OU Ltd. | Wholesale & retail | 2025 |
| Jibos IT Limited | Information & communication | 2003 |
| JIE HUA XIE Ltd. | Wholesale & retail | 2025 |
| Jiggle Innovations Limited | Information & communication | 2023 |
| Jigsaw Scenery Limited | Construction | 2015 |
| Jigworks Ltd | Information & communication | 2025 |
| Jijoho Estate Limited | Real estate | 2024 |
| Jikaze Ltd | Health & social care | 2013 |
| JIM Hickey Limited | Information & communication | 2011 |
| JIM Meadows Building Services Ltd | Construction | 2017 |
| Jimmy Killer MK Ltd | Hospitality | 2025 |
| Jimmy Killer Prawns MK Ltd | Financial services | 2025 |
| Jimmythegiant Ltd | Manufacturing | 2024 |
| Jinchan Digital Technology Ltd. | Wholesale & retail | 2024 |
| Jinder Grewal Investment Empire Limited | Real estate | 2025 |
| Jing XI KJ Ltd. | Wholesale & retail | 2025 |
| Jingling Digital Technology Ltd | Wholesale & retail | 2024 |
| Jinshi Digital Technology Ltd | Wholesale & retail | 2024 |
| Jinzee Ltd | Wholesale & retail | 2025 |
| Jipis Limited | Administrative & support | 2010 |
| Jireh Ideas Limited | Real estate | 2025 |
| Jireh Sources Limited | Professional & scientific | 2016 |
| Jiriengwa Investments Limited | Real estate | 2020 |
| JIT Hospitality Ltd | Information & communication | 2026 |
| Jittla Associates Ltd | Professional & scientific | 2023 |
| Jiyuvending Ltd | Wholesale & retail | 2025 |
| JJ Dream Nest Ltd | Real estate | 2025 |
| JJ Finedge Ltd | Professional & scientific | 2025 |
| JJ Foodz Ltd | Professional & scientific | 2023 |
| JJ Kong General Builder Ltd | Construction | 2025 |
| JJ Land Limited | Administrative & support | 2000 |
| JJ Recruits Ltd | Administrative & support | 2024 |
| JJ Stars Services Limited | Transport & logistics | 2016 |
| JJA Properties Limited | Real estate | 2019 |
| JJC Labour Supply Ltd | Construction | 2015 |
| Jjitc Business Limited | Information & communication | 2018 |
| Jjjoye Limited | Administrative & support | 2017 |
| Jjpt Ultrasound Services Limited | Health & social care | 2005 |
| JJW Architecture Ltd | Professional & scientific | 2021 |
| JK Aero Limited | Transport & logistics | 2012 |
| JK AP Holding Limited | Administrative & support | 2022 |
| JK Creative Enterprises Ltd | Administrative & support | 2022 |
| JK Langdale Limited | Professional & scientific | 2017 |
| JK Logistics Europe Ltd | Professional & scientific | 2009 |
| JK Private Hire Ltd | Transport & logistics | 2026 |
| JK Supplies Ltd | Wholesale & retail | 2015 |
| JK Travel MK Limited | Administrative & support | 2019 |
| JK Wine Store Ltd | Wholesale & retail | 2020 |
| Jkdpubs Ltd | Hospitality | 2025 |
| JKI Capital Limited | Information & communication | 2016 |
| JKL Retail & Distribution Limited | Wholesale & retail | 2023 |