| JT Complete Services Limited | Construction | 2023 |
| JT Family Limited | Hospitality | 2025 |
| JT Prestige Chauffeurs Ltd | Transport & logistics | 2023 |
| JTA Business Consulting Ltd | Professional & scientific | 2024 |
| JTB Project Ltd | Real estate | 2024 |
| JTJ Ventures Ltd | Financial services | 2026 |
| JTM Construction & Maintenance Ltd | Construction | 2021 |
| Jtron Europe Ltd | Construction | 2024 |
| JU88STER Music Ltd. | Information & communication | 2013 |
| Jubilee Counselling and Help Centre CIC | Education | 2024 |
| Jubilee Global Missions Ltd | Education | 2020 |
| Jubnaj Enterprise Ltd | Information & communication | 2022 |
| Judge Construction Group Ltd | Construction | 2024 |
| Judge Construction Limited | Construction | 2017 |
| Juju Enterprises Ltd | Information & communication | 2016 |
| Jukonis Projects Limited | Professional & scientific | 2016 |
| Julakanti's Retail Limited | Wholesale & retail | 2026 |
| Julia and YOU Limited | Professional & scientific | 2016 |
| Julia P Limited | Health & social care | 2015 |
| Julia PT Limited | Real estate | 2023 |
| Julian B Ltd | Construction | 2021 |
| Juliano Ltd | Construction | 2017 |
| Julie James Limited | Extraterritorial | 2016 |
| Jumar Properties Limited | Real estate | 2019 |
| Jumeirah Palm Lounge Limited | Hospitality | 2019 |
| Jumero Ltd | Real estate | 2017 |
| Jumqa Ltd | Wholesale & retail | 2026 |
| Junerace Limited | Wholesale & retail | 2020 |
| Jungle Ventures Limited | Arts & recreation | 2026 |
| Juniormax Ltd | Construction | 2019 |
| Junkiri Initiative Ltd | Wholesale & retail | 2023 |
| Jurassic Coast Coffee Limited | Hospitality | 2010 |
| Jurra Healthtech Ltd | Public administration | 2025 |
| Just Brew Catering Ltd | Hospitality | 2023 |
| Just Brew Ltd | Hospitality | 2022 |
| Just Cake Treats CIC | Hospitality | 2025 |
| Just DO Care Services Ltd | Health & social care | 2019 |
| Just Drinks 4U UK Ltd | Wholesale & retail | 2020 |
| Just Gardens Ltd | Administrative & support | 2004 |
| Just Joyful Touch Ltd | Other services | 2019 |
| Just Primary Care Ltd. | Health & social care | 2021 |
| Just Productions International Ltd | Professional & scientific | 2007 |
| Just Roti Limited | Hospitality | 2020 |
| Just Think Dog Limited | Other services | 2023 |
| JUST4PLANTS Ltd. | Agriculture & fishing | 2018 |
| Justessentially Ltd | Wholesale & retail | 2025 |
| Justrade Limited | Wholesale & retail | 2025 |
| Justwear Ltd | Wholesale & retail | 2018 |
| Jutsums Court (Romford) Residents Company Limited | Professional & scientific | 1980 |
| Jutt Wave Records Ltd | Information & communication | 2020 |
| Juwon Care Services Limited | Health & social care | 2017 |
| JV Magicmans Ltd | Construction | 2022 |
| JVC Housing Ltd | Real estate | 2020 |
| JVG New Home Construction Ltd | Construction | 2021 |
| JW Tech Ltd | Information & communication | 2012 |
| K & C London Limited | Hospitality | 2018 |
| K & G Construction Ltd | Construction | 2023 |
| K & L Group Limited | Manufacturing | 1986 |
| K & M Distribution Limited | Transport & logistics | 2024 |
| K & M Garnham Limited | Real estate | 2023 |
| K Brothers Industries Ltd | Wholesale & retail | 2022 |
| K C J a Property Ltd | Real estate | 2025 |
| K D Cabs Limited | Transport & logistics | 2024 |
| K G Gilbert Limited | Real estate | 2021 |
| K G Plumbing Services Ltd | Construction | 2025 |
| K Infinity Limited | Wholesale & retail | 2023 |
| K Project Management Limited | Construction | 2025 |
| K Rich Properties Ltd | Real estate | 2026 |
| K S Maintenance Limited | Construction | 2002 |
| K T Window Solutions Limited | Construction | 2019 |
| K&E Cleaning UK Ltd | Wholesale & retail | 2024 |
| K&K Urban Lettings Ltd | Real estate | 2025 |
| K&N Services Limited | Professional & scientific | 2020 |
| K&R Solutions Ltd | Information & communication | 2016 |
| K&Ss Properties Ltd | Real estate | 2020 |
| K-Bespoke Homes Ltd | Construction | 2024 |
| K-Dems Consulting Limited | Professional & scientific | 2025 |
| K-Max IT Services Ltd | Information & communication | 2026 |
| K-Pop Idol Trainee School London Limited | Arts & recreation | 2020 |
| K-Pop Training Camp UK Limited | Arts & recreation | 2020 |
| K-Tech Electrical Services Limited | Construction | 2019 |
| K-Win London Ltd | Wholesale & retail | 2021 |
| K.H International Ltd | Real estate | 2023 |
| K.M.G Group Ltd | Wholesale & retail | 2025 |
| K.M.P. Commissioning Limited | Construction | 2013 |
| K.P. Fencing Ltd | Construction | 1997 |
| K.R.D. Homes & Lettings Ltd | Real estate | 2025 |
| K.S Shutters Ltd | Construction | 2010 |
| K.S.L. Thomas & Co. Limited | Financial services | 1961 |
| K1 Removals and Storage Limited | Transport & logistics | 2022 |
| K1 Transport Ltd | Transport & logistics | 2016 |
| K1NDER Investments Ltd | Real estate | 2026 |
| K2 Health Limited | Health & social care | 2014 |
| K2 Hills Ltd | Wholesale & retail | 2023 |
| K2VD Ltd | Education | 2023 |
| K4L Limited | Health & social care | 2014 |
| K9 Catering Ltd | Wholesale & retail | 2017 |
| K9 Hotels Limited | Other services | 2013 |
| K9 Security Dogs Ltd | Administrative & support | 2022 |
| KA Cafe Ltd | Hospitality | 2025 |