| I GOT Your Back Ltd | Manufacturing | 2015 |
| ICC Automotive Wolverhampton Ltd | Wholesale & retail | 2023 |
| Icentral Heating & Plumbing Limited | Construction | 2020 |
| Ideal Car Centre Ltd | Wholesale & retail | 2017 |
| Idream One Ltd | Construction | 2024 |
| Igodoo Store Ltd | Wholesale & retail | 2023 |
| IK Noor Ltd | Wholesale & retail | 2021 |
| IM Recovery Ltd | Wholesale & retail | 2025 |
| Imarfo & Co Ltd | Wholesale & retail | 2021 |
| Immo Solutions Limited | Wholesale & retail | 2024 |
| Impact Demolitions Ltd | Construction | 2024 |
| Impacta Limited | Manufacturing | 2000 |
| IN ACC Services Limited | Professional & scientific | 2019 |
| Indian Grill & Bar Ltd | Hospitality | 2025 |
| Indus-Serve Limited | Construction | 1974 |
| INK and Aesthetics Studio Ltd | Other services | 2026 |
| Inkbonez Tattoo Studio Limited | Other services | 2019 |
| Inlpd Logistics Ltd | Transport & logistics | 2025 |
| Inner Industrious I Ltd | Professional & scientific | 2017 |
| Inspired Paths Learning Journey CIC | Education | 2026 |
| Inspirerealm Limited | Administrative & support | 2024 |
| Integrated Global Services and Solutions (Igss) Ltd | Administrative & support | 2024 |
| Intel Training Academy and Storage UK Ltd. | Wholesale & retail | 2024 |
| Intercontex (Contractors) Limited | | 1988 |
| Investorgates Limited | Real estate | 2024 |
| Invincible Mail Limited | Transport & logistics | 2019 |
| Iqra Research Ltd | Education | 2023 |
| Irene Prosper Limited | Health & social care | 2022 |
| Isha Property Groups Ltd | Real estate | 2025 |
| IT UP Limited | Information & communication | 2019 |
| J S Siyan Construction Limited | Construction | 2020 |
| J Summerfield & Co Limited | Professional & scientific | 2012 |
| J Wilkins QA Ltd | Hospitality | 2020 |
| J&L Motor Company Ltd | Wholesale & retail | 2026 |
| J&N N Ltd | Transport & logistics | 2018 |
| J&T Carriers Ltd | Transport & logistics | 2017 |
| J. D. Distribution Ltd | Other services | 1997 |
| J. Lees Motor Services Limited | Wholesale & retail | 2005 |
| J.M.C Construction (Midlands) Limited | Construction | 2023 |
| J1 Homes Ltd | Real estate | 2021 |
| J2 Homes Limited | Real estate | 2016 |
| Jack Wall Fitness Ltd | Health & social care | 2025 |
| Jackyem Shipping and Logistics Limited | Transport & logistics | 2026 |
| Jactone Holdings Limited | Financial services | 2026 |
| Jactone Products Limited | Manufacturing | 1987 |
| Jajo Automated Software Limited | Professional & scientific | 2004 |
| Jamae Ltd | Transport & logistics | 2026 |
| Jamaica Produce Ltd | Wholesale & retail | 2015 |
| Jamelia Enterprise Limited | Health & social care | 2025 |
| James Balfour Public Limited Company | Wholesale & retail | 1990 |
| Jamescroft Accountants Limited | Professional & scientific | 2022 |
| Jandor Transports Service Ltd | Transport & logistics | 2021 |
| JAP Repairs & Conversions Ltd | Wholesale & retail | 2023 |
| Japji Chhina Ltd | Wholesale & retail | 2019 |
| Jarr Group Ltd | Real estate | 2026 |
| Jarvis Home Solutions Limited | Construction | 2024 |
| JAS Activities Limited | Wholesale & retail | 2024 |
| JAS Buy to LET Ltd | Real estate | 2022 |
| Jasbir Kaur Madahar Limited | Extraterritorial | 2024 |
| Jatindera Auto Works Ltd | Wholesale & retail | 2024 |
| Jawani Nights Ltd | Arts & recreation | 2025 |
| Jaykev Limited | Wholesale & retail | 2017 |
| Jays Renovations Ltd | Construction | 2025 |
| JB Fusion Crew Ltd | Education | 2025 |
| JB UK Solutions Ltd | Wholesale & retail | 2026 |
| JBC Structures Limited | Construction | 2020 |
| JC Boxing Limited | Education | 2020 |
| JCN Ventures Limited | Hospitality | 2021 |
| Jcresswell Ltd | Transport & logistics | 2023 |
| JD Graphic and Design UK Ltd | Professional & scientific | 2025 |
| JD Motors 1 Ltd | Extraterritorial | 2025 |
| JDI Logistics Limited | Administrative & support | 2018 |
| Jebra Consultancy Limited | Professional & scientific | 2022 |
| Jeet Pro Films Ltd | Professional & scientific | 2023 |
| JHL Investments Ltd | Real estate | 2022 |
| JHL Transport Ltd | Transport & logistics | 2017 |
| Jhmg Ltd | Hospitality | 2023 |
| Jigar Transport Limited | Transport & logistics | 2017 |
| JIN Song LIN Ltd | Extraterritorial | 2013 |
| Jisp Group Ltd | Professional & scientific | 2025 |
| Jj's Fish Bar Ltd | Hospitality | 2026 |
| JJD Property Development Limited | Construction | 2002 |
| JJL Travel Limited | Administrative & support | 2023 |
| Jjlm Consultants Ltd | Construction | 2026 |
| JJS Mann Retail Limited | Wholesale & retail | 2019 |
| JK Fitting Ltd | Construction | 2022 |
| JL Residences Ltd | Construction | 2024 |
| JM FAR & Wide Cleaning Services Limited | Administrative & support | 2011 |
| JN Community Care Limited | Health & social care | 2017 |
| Jnagal Limited | Professional & scientific | 2012 |
| JNR Global Ltd | Information & communication | 2025 |
| JO & Steph Ltd | Administrative & support | 2022 |
| Jodh Bargains Ltd | Wholesale & retail | 2024 |
| Joes Car Dismantlers Ltd | Extraterritorial | 2013 |
| Jogle Couriers Limited | Transport & logistics | 2003 |
| Johal's Money Saving Consultancy Ltd | Professional & scientific | 2025 |
| John Kane Kars Ltd | Wholesale & retail | 2018 |
| Joint Welding and Fabrication Ltd | Manufacturing | 2019 |
| Jollofpeople Limited | Hospitality | 2024 |
| Jomar Trans Ltd | Administrative & support | 2020 |