| INNOV8 Partnerships Ltd | Administrative & support | 2026 |
| Innovative Projects (UK) Limited | Construction | 2009 |
| Innovative Specialized Security Service Ltd | Manufacturing | 2024 |
| Innovativedigital Limited | Professional & scientific | 2026 |
| Inspire Nursery Group Limited | Health & social care | 2023 |
| Inspire Sports Coach Ltd | Education | 2018 |
| Inspiring ALL Minds Ltd | Information & communication | 2023 |
| Instant Ltd | Construction | 2025 |
| Integrated Electrical Solutions Limited | Construction | 2006 |
| Integrated Masonry Services Ltd | Construction | 2014 |
| Integrated Security Systems Ltd | Construction | 2026 |
| Intelligent Exchanges Limited | Information & communication | 2025 |
| Interact Entertainments Limited | Arts & recreation | 2003 |
| Interim Asset Holdings Limited | Real estate | 2022 |
| Interim Enterprises Limited | Administrative & support | 2006 |
| Interim Fuel Group Limited | Wholesale & retail | 2022 |
| Interior Software Solutions Limited | Information & communication | 2012 |
| International Coaching Limited | Education | 2014 |
| International Conference Events Limited | Other services | 2009 |
| International Luxury Auctions Limited | Wholesale & retail | 2023 |
| International Store OL6 Limited | Wholesale & retail | 2025 |
| International Trauma Conferences | Health & social care | 2008 |
| Intraconnect Ltd | Wholesale & retail | 2021 |
| Inventive Guaranteeco Limited | Wholesale & retail | 2014 |
| Investt Ltd | Construction | 2025 |
| Inzi Film Production Limited | Information & communication | 2024 |
| Ipharmacy Direct Ltd | Wholesale & retail | 2012 |
| Ipro Engineering Ltd | Professional & scientific | 2014 |
| IQ Investments Ltd | Real estate | 2026 |
| IQ Protections Ltd | Administrative & support | 2024 |
| Ireeds Limited | Financial services | 2000 |
| Irfan Khan Ltd | Financial services | 2011 |
| Irwell Laboratory Services Ltd | Professional & scientific | 2024 |
| IS Construction (N/W) Ltd | Construction | 2013 |
| ISS Investment and Development Ltd | Construction | 2018 |
| ISS Management Company Limited | Construction | 2015 |
| ISS Property Investment Limited | Construction | 2015 |
| ISS Property Limited | Construction | 2018 |
| IT Pioneer Solution Ltd | Wholesale & retail | 2024 |
| Itaspera Limited | Education | 2011 |
| Itech Corner Ltd | Wholesale & retail | 2024 |
| Ivotrans Ltd | Wholesale & retail | 2014 |
| J & G Site Management Services Ltd | Construction | 2005 |
| J Barton Road Surfacing Ltd | Construction | 2008 |
| J FIX Joinery Limited | Construction | 2023 |
| J S Fit Kids Limited | Arts & recreation | 2013 |
| J Thompson Accountancy & Payroll Services Ltd | Professional & scientific | 2021 |
| J&M Foods Ltd | Wholesale & retail | 2019 |
| J.A.R. Designs (NW) Ltd | Wholesale & retail | 2012 |
| J.H.S Sales Ltd | Wholesale & retail | 2023 |
| J.K. Owen & Sons Ltd | Transport & logistics | 2006 |
| J.Klein Media Production Ltd | Information & communication | 2025 |
| J.M Clinic Ltd | Health & social care | 2023 |
| J.M Cosmetics Ltd | Other services | 2023 |
| JA Adventures Ltd | Wholesale & retail | 2018 |
| JA Joinery and Sons Limited | Construction | 2022 |
| Jaag Construction Ltd | Construction | 2025 |
| Jack Decoration Ltd | Construction | 2026 |
| Jack Hughes Tattoos Ltd | Arts & recreation | 2023 |
| Jack.L.S Ltd | Wholesale & retail | 2025 |
| Jacksons Sign Makers Ltd | Manufacturing | 2025 |
| Jackworm Ltd | Information & communication | 2014 |
| Jacqueline Bowker Limited | Financial services | 2023 |
| Jadegarden AUL Ltd | Hospitality | 2024 |
| Jades Hairdressing Limited | Other services | 2020 |
| JAG Remedials Ltd | Construction | 2016 |
| Jahnavi's Bites Ltd | Hospitality | 2025 |
| Jalasai Ltd | Wholesale & retail | 2025 |
| Jamatech Ltd | Manufacturing | 2025 |
| James G Investments Limited | Real estate | 2020 |
| James Hartshorne Electrical Ltd | Construction | 2014 |
| James Hayes (Ravenscourt Park) Ltd | Real estate | 2021 |
| James Hourigan Limited | Construction | 2015 |
| James Mcallister Electrical Ltd | Construction | 2010 |
| James Meakin Joinery Ltd | Construction | 2020 |
| James Ticer Ltd | Wholesale & retail | 2024 |
| JAP Cars UK Limited | Wholesale & retail | 2026 |
| Jarga UK Ltd | Wholesale & retail | 2025 |
| Jarvis Events Ltd | Education | 2024 |
| Jason O'Brien & Family Funeral Services Limited | Other services | 2012 |
| Jason Peel Ltd | Arts & recreation | 2013 |
| Jateen LAD Limited | Professional & scientific | 2015 |
| Jaxson Properties Ltd | Real estate | 2022 |
| Jayne Joseph Training Ltd | Professional & scientific | 2017 |
| JB Irwin Limited | Administrative & support | 2018 |
| JBL (Welding) Ltd | Manufacturing | 2010 |
| Jbno Ltd | Hospitality | 2018 |
| JBS Electrical Contractors Ltd | Construction | 2017 |
| Jcal Engineering Solutions Limited | Professional & scientific | 2019 |
| Jcarringtonautomation Ltd | Professional & scientific | 2024 |
| JCD Consultants Ltd | Professional & scientific | 2014 |
| JCH Ltd | Wholesale & retail | 2024 |
| JCP Ventures Limited | Real estate | 2023 |
| JD Accounting Ltd | Professional & scientific | 2017 |
| JD Ghedia & Sons Limited | Wholesale & retail | 2014 |
| Jd's Vehicle Care Ltd | Wholesale & retail | 2019 |
| Jean Dinca Limited | Transport & logistics | 2025 |
| Jean Trader's Limited | Wholesale & retail | 2025 |
| Jedline Ltd | Other services | 2020 |
| Jessica Alice Tattoo Ltd | Arts & recreation | 2022 |