| Interprop Ltd | Real estate | 2022 |
| Interstoq Ltd. | Wholesale & retail | 2015 |
| Into IT Limited | Information & communication | 1999 |
| Intobulk Ltd | Transport & logistics | 2024 |
| Intrepid Leadership Consulting Limited | Education | 2015 |
| Intruder Aware Limited | Administrative & support | 2023 |
| Intuity Gaming Limited | Information & communication | 2017 |
| Intuveus Ltd | Professional & scientific | 2023 |
| Inula Beauty Limited | Other services | 2015 |
| Invara Ltd | Real estate | 2026 |
| Invent Consultancy Limited | Education | 2021 |
| Inventive Canvas Ltd | Information & communication | 2023 |
| Inventsys Limited | Information & communication | 2008 |
| Investiamo Limited | Real estate | 2025 |
| Investment Building UK Ltd | Construction | 2015 |
| Investors in the Community Fund II LP | | 2003 |
| Investors in the Community LP | | 2010 |
| Investplus Limited | Administrative & support | 2001 |
| Invictus Capital Finance Limited | Financial services | 2015 |
| Invictus Energy Consultants Limited | Energy | 2021 |
| Invind Ltd | Information & communication | 2013 |
| Invoart Ltd | Information & communication | 2025 |
| Inzero World Ltd | Professional & scientific | 2024 |
| IOG Solutions Limited | Administrative & support | 2026 |
| Iona Scott-Mathieson Ltd | Professional & scientific | 2024 |
| Iovu Financial Services Ltd | Financial services | 2022 |
| Iovu Logistics Ltd | Transport & logistics | 2021 |
| IPC Consulting Limited | Professional & scientific | 2018 |
| IPC Investigations Limited | Extraterritorial | 2021 |
| IPH (2016) Limited | Construction | 2020 |
| Iplan Studio Ltd | Information & communication | 2025 |
| Ipoe Consulting Limited | Professional & scientific | 2022 |
| Irate Entertainment Ltd | Information & communication | 2020 |
| Iris EYE Ltd | Health & social care | 2022 |
| Irlspace Ltd | Information & communication | 2024 |
| Iron Giant Financial Ltd | Financial services | 2013 |
| Isa.Connect CIC | Education | 2024 |
| Isaa Tech Ltd | Information & communication | 2022 |
| Isaac Otis Limited | Manufacturing | 2022 |
| Ischus Property Junior Ltd | Real estate | 2020 |
| Isee Access Solutions Limited | Construction | 2013 |
| ISH Living Limited | Real estate | 2019 |
| Isipho Wraps Ltd | Manufacturing | 2026 |
| Island Estates Chelmsford Limited | Construction | 2019 |
| Island Touch Ltd | Hospitality | 2023 |
| Ismail Transport Ltd | Transport & logistics | 2021 |
| Isos Equity Ltd | Real estate | 2026 |
| IT and Accounting Limited | Information & communication | 2024 |
| IT Girl Body Sculpting Academy Ltd | Other services | 2024 |
| IT Response Ltd | Information & communication | 2012 |
| IT Systems Simplified Ltd | Information & communication | 2026 |
| IT Venturez Limited | Information & communication | 2019 |
| It's Your Magazines Ltd | Information & communication | 2019 |
| Italia NEL Mondo (UK) Limited | Administrative & support | 1991 |
| Iteam Repairs Ltd | Other services | 2014 |
| Itec 32 Limited | Information & communication | 2007 |
| Itisus Limited | Information & communication | 2013 |
| ITS Your Media Ltd | Information & communication | 2014 |
| Itsky Solutions Limited | Information & communication | 2023 |
| Iubireamea Limited | Hospitality | 2018 |
| Iulian Burca Ltd | Transport & logistics | 2025 |
| Iuvo Investments Limited | Real estate | 2020 |
| Iuvo Services Limited | Professional & scientific | 2005 |
| Ivacon Limited | Transport & logistics | 2013 |
| Ivepaid.Co.Uk Ltd | Financial services | 2017 |
| Ivepaid.Com Limited | Financial services | 2017 |
| IVY & Stone Estates Essex Limited | Real estate | 2025 |
| Ivymuir Investments Ltd | Real estate | 2022 |
| Iwantclubkit Ltd | Arts & recreation | 2021 |
| Ixplora Technologies Limited | Information & communication | 2011 |
| IZ Building Limited | Construction | 2021 |
| Izin Smart Ltd | Hospitality | 2019 |
| Izzylfit Ltd | Education | 2023 |
| J & a International Properties Ltd | Real estate | 2022 |
| J & D Holdings Essex Ltd | Financial services | 2021 |
| J & FM Limited | Financial services | 2025 |
| J & J Fruits and Food Ltd | Wholesale & retail | 2022 |
| J & K Build Ltd | Construction | 2021 |
| J & M Homes (Abbess Roding) Limited | Other services | 2023 |
| J & M Homes (Fryerning) Limited | Real estate | 2024 |
| J & M Homes (Park Road) Limited | Other services | 2026 |
| J & M Homes (Sawbridgeworth) Limited | Other services | 2025 |
| J & M Homes (South East) Limited | Other services | 2016 |
| J & S Clarke Ltd | Construction | 2020 |
| J & S Clarke Properties Ltd | Real estate | 2024 |
| J & S Essex Limited | Health & social care | 2008 |
| J a Hazell Heating & Plumbing Ltd | Construction | 2018 |
| J a L R Limited | Agriculture & fishing | 2023 |
| J a Wright Roofing Limited | Construction | 2019 |
| J Bell Design and Conservation Ltd | Construction | 2019 |
| J C M Services Amenity and Groundcare Limited | Agriculture & fishing | 2019 |
| J Clarke Property Solutions Ltd | Real estate | 2025 |
| J D Contracts (London) Limited | Construction | 1999 |
| J F L Projects Limited | Construction | 2017 |
| J Freeman Smart Repairs Limited | Wholesale & retail | 2014 |
| J G Electrical Contractors Ltd | Construction | 2015 |
| J G Roofing (Essex) Ltd | Construction | 2023 |
| J H Burton Limited | Real estate | 2020 |
| J H Flooring Solutions Limited | Construction | 2018 |
| J Hangers Ltd | Other services | 2013 |