| Italy Summit Lake Trading Company Limited | Wholesale & retail | 2025 |
| ITC International Limited | Professional & scientific | 2023 |
| Itda Soft Ltd | Information & communication | 2024 |
| Itech Industry Co., Ltd | Wholesale & retail | 2018 |
| Iteclogix Limited | Information & communication | 2023 |
| Itek Aero Investment Co., Ltd | Manufacturing | 2024 |
| Itero Ltd | Wholesale & retail | 2025 |
| Itiger Ltd | Wholesale & retail | 2025 |
| Itinera Nubes Ltd | Professional & scientific | 2024 |
| Itish Byte Ltd | Wholesale & retail | 2026 |
| Itproc Ltd | Information & communication | 2025 |
| Itrs Consulting Ltd | Information & communication | 2023 |
| Itsmindovermatter CIC | Health & social care | 2025 |
| Iuiu Network Limited | Wholesale & retail | 2023 |
| Iukoi Limited | Wholesale & retail | 2025 |
| Ivnconsulting Ltd | Professional & scientific | 2025 |
| IVY & Marley Ltd | Wholesale & retail | 2026 |
| IVY Grace 25 Ltd | Wholesale & retail | 2026 |
| IVY Park Properties Limited | Real estate | 2016 |
| Iwedicomms Limited | Information & communication | 2018 |
| Iwinnor Ltd | Extraterritorial | 2024 |
| Iyjtho Wfdtwf Trading Limited | Wholesale & retail | 2025 |
| Izec Limited | Wholesale & retail | 2026 |
| Izwi Group Limited | Wholesale & retail | 2026 |
| J & N Renewables Ltd | Professional & scientific | 2026 |
| J & P Turner | Agriculture & fishing | 1961 |
| J & R Property Solutions Ltd | Administrative & support | 2025 |
| J Chuanyun Limited | Wholesale & retail | 2025 |
| J D M Property Maintenance Ltd | Construction | 2024 |
| J Dongf Limited | Wholesale & retail | 2025 |
| J Jiangahui Limited | Wholesale & retail | 2024 |
| J M Build Services Ltd | Construction | 2024 |
| J Moffat Property Ltd | Real estate | 2022 |
| J Seven Trade Ltd | Wholesale & retail | 2025 |
| J&D Contractors Ltd | Information & communication | 2025 |
| J&G Biotech Ltd | Administrative & support | 2013 |
| J&H Import&Export Co., Ltd | Administrative & support | 2023 |
| J&P Legal Limited | Professional & scientific | 2022 |
| J&S Prestige Facades Ltd | Construction | 2022 |
| J.Y.E. Ltd | Information & communication | 2024 |
| J100 Ltd | Construction | 2026 |
| Jackhat Consulting Ltd | Real estate | 2026 |
| Jackson Street Group Limited | Water & waste | 2017 |
| Jacobson Enterprises Unlimited Ltd | Information & communication | 2025 |
| Jade-Tec Solutions Limited | Information & communication | 2003 |
| Jadedragon Machinery Co., Ltd | Administrative & support | 2023 |
| Jadeolds Ltd | Wholesale & retail | 2025 |
| Jaderiver Ltd | Wholesale & retail | 2025 |
| Jady International Co., Ltd | Administrative & support | 2014 |
| Jafar UK Ltd | Professional & scientific | 2011 |
| JAG Ateliers Ltd | Information & communication | 2026 |
| Jahn Media Limited | Information & communication | 2019 |
| Jake Vision Ltd | Real estate | 2021 |
| Jakops Group Limited | Real estate | 2026 |
| Jamaican Products Ltd | Manufacturing | 2022 |
| James & Frank Ltd | Real estate | 2025 |
| James Flynn Consulting Ltd | Professional & scientific | 2024 |
| James Harrison Design Services Ltd | Professional & scientific | 2020 |
| James Hayashi Enterprises Limited | Wholesale & retail | 2020 |
| James International Trading Ltd | Manufacturing | 2024 |
| James Tours Ltd | Administrative & support | 2023 |
| Jameson Resources Limited | Administrative & support | 2026 |
| Jami Optical Co., Ltd | Administrative & support | 2014 |
| Jamie Adamson Hairdressing Limited | Other services | 2011 |
| Jamiejphotography Ltd | Professional & scientific | 2024 |
| Jamil and Nyanga Jaward Foundation | Other services | 2019 |
| Jammed Limited | Information & communication | 2007 |
| Jane and JOE in the Bungalow Ltd | Information & communication | 2024 |
| Janebear Life Ltd | Administrative & support | 2021 |
| Janejoy Ltd | Extraterritorial | 2024 |
| Janet Smith UK Ltd | Extraterritorial | 2025 |
| Jangor Investment Limited | Professional & scientific | 2021 |
| Janmerl Property Ltd | Real estate | 2025 |
| Jannalukmomo Ltd | Wholesale & retail | 2025 |
| JAR Partners Ltd | Real estate | 2025 |
| Jareen Ltd | Wholesale & retail | 2025 |
| Jarliy Limited | Wholesale & retail | 2025 |
| Jaromir Ltd | Transport & logistics | 2024 |
| Jarveo Ltd | Other services | 2020 |
| Jasmin Orange Ltd | Wholesale & retail | 2024 |
| Jason Global LLP | | 2012 |
| Jasper Building & Joinery Contractors Ltd | Other services | 2012 |
| Jasper Developments Ltd | Construction | 2025 |
| Jasper Health More Ltd | Wholesale & retail | 2025 |
| Jasteg Consults Ltd | Information & communication | 2025 |
| Jatoc Ltd | Real estate | 2024 |
| Jaunty Blossom Limited | Manufacturing | 2023 |
| Jaura's Tradenest Ltd | Wholesale & retail | 2025 |
| Jawy Ltd | Wholesale & retail | 2024 |
| JAX Fitter Ltd | Wholesale & retail | 2020 |
| JAY Mortel Fshion Limited | Wholesale & retail | 2026 |
| JAY Publishing Ltd | Information & communication | 2026 |
| Jaybridge Estates Ltd | Real estate | 2026 |
| Jaydaniels Staffing Ltd | Health & social care | 2023 |
| Jayel Enterprises Ltd | Extraterritorial | 2011 |
| Jaymizy Ltd | Health & social care | 2023 |
| Jayne Louise Hackley Limited | Extraterritorial | 2021 |
| Jayte Services Limited | Health & social care | 2026 |
| Jazberia Deals Limited | Wholesale & retail | 2025 |
| Jazmin Pinner Fashion Limited | Wholesale & retail | 2026 |