| Iamavibe Ltd | Wholesale & retail | 2021 |
| IAN Black and Associates Ltd | Administrative & support | 2002 |
| IAN Bone Visiting Tailor Limited | Administrative & support | 2002 |
| IAN Hampton Graves Limited | Health & social care | 2002 |
| Icoves Ltd | Professional & scientific | 2014 |
| Icss Systems Limited | Professional & scientific | 2013 |
| Identity on Tyne CIC | Education | 2023 |
| IFA Car Finance Ltd | Wholesale & retail | 2011 |
| Ignite 100 Accelerator Corp Limited | Administrative & support | 2013 |
| Ignite GAS Training Limited | Education | 2015 |
| Ignite Holdings Ltd | Administrative & support | 2015 |
| Ignite Nominee Limited | Administrative & support | 2015 |
| Ignite Plumbing and Heating Supplies Limited | Wholesale & retail | 2015 |
| Ignite Training Ltd | Administrative & support | 2014 |
| IKI Art Limited | Arts & recreation | 2026 |
| Ikou Limited | Wholesale & retail | 2025 |
| Im&E AS Ltd | Other services | 2022 |
| IMD Project Engineering Ltd | Professional & scientific | 2010 |
| Immersion Esports Ltd | Arts & recreation | 2023 |
| Imperial Infusions Limited | Wholesale & retail | 2020 |
| Imperial Racing Club Limited | Arts & recreation | 2010 |
| IN the Black Consultancy Limited | Administrative & support | 2019 |
| Incrediwear UK Limited | Health & social care | 2024 |
| Independent Advocacy North East | Health & social care | 2012 |
| Infinity RG Limited | Real estate | 2025 |
| Inflo (Apac) Limited | Information & communication | 2019 |
| Inflo (Emea) Limited | Information & communication | 2017 |
| Inflo Group Limited | Information & communication | 2015 |
| Inman Leaver Limited | Health & social care | 2019 |
| Inner Security Limited | Information & communication | 2026 |
| Innovate Pro Global Ltd | Wholesale & retail | 2024 |
| Innovating for Wellbeing Limited | Professional & scientific | 2023 |
| Innovation Scout Limited | Professional & scientific | 2008 |
| Inradium Ltd | Information & communication | 2020 |
| Insight Finance Directors Limited | Professional & scientific | 2021 |
| Insight Properties Ltd | Hospitality | 2024 |
| Insights Business Psychology Ltd. | Professional & scientific | 2018 |
| Inskip Coatings NE Ltd | Manufacturing | 2024 |
| Inspiration North Community Interest Company | Education | 2023 |
| Instagig HQ Limited | Arts & recreation | 2026 |
| Insulcon Technical Limited | Administrative & support | 2019 |
| Integrative Bodywork Ltd | Wholesale & retail | 2025 |
| Interkool Refrigeration & Air Conditioning Ltd | Energy | 2015 |
| International Windows & Conservatories Limited | Construction | 2003 |
| Interstyle Northeast Ltd | Construction | 2020 |
| Interview Room One Limited | Administrative & support | 2024 |
| Intumescent Protective Coatings ( Holdings ) Limited | Construction | 2020 |
| Intumescent Protective Coatings Limited | Construction | 1998 |
| Invasion Angels Ltd | Administrative & support | 2014 |
| Investire Properties Ltd | Real estate | 2023 |
| Invicti Ltd | Professional & scientific | 2017 |
| Ipinyou UK Limited | Professional & scientific | 2018 |
| Ipizza Ltd | Hospitality | 2025 |
| Iqit Digital Ltd | Information & communication | 2012 |
| Isochem Polyurethanes UK Ltd | Wholesale & retail | 2018 |
| Isoclad Limited | Manufacturing | 2003 |
| Itbs - IT and Business Systems Limited | Information & communication | 2013 |
| Ivory Stone Ltd | Information & communication | 2015 |
| Iwantaboiler Ltd | Construction | 2025 |
| J & N Housekeeping Ltd | Administrative & support | 2024 |
| J a D Marine Limited | Professional & scientific | 2008 |
| J B H Design and Exhibitions Limited | Arts & recreation | 1994 |
| J Campey DRY Lining and Building Services Ltd | Construction | 2025 |
| J Charlton & Sons Limited | Hospitality | 2009 |
| J David Investments Limited | Real estate | 2025 |
| J Hope Electrical Services Ltd | Construction | 2022 |
| J&M Plumbing & Heating NE Ltd | Construction | 2022 |
| J.Ar Legal Services Limited | Professional & scientific | 2024 |
| J.E Wallace Ltd | Construction | 2025 |
| J.J. Properties (Northern) Limited | Real estate | 2006 |
| J.O.S.L. Property Ltd | Real estate | 2025 |
| Jaci Lets Limited | Households | 2025 |
| Jack Jacob Investments Limited | Real estate | 2021 |
| Jack Jacobs Holdings Ltd | Professional & scientific | 2016 |
| Jackson Farm Court Ltd | Households | 2023 |
| Jagtec Recruitment Limited | Administrative & support | 2017 |
| JAH Building & Developments Ltd | Construction | 2019 |
| Jakobs Engineering Group Ltd | Professional & scientific | 2022 |
| James Burwood Engineering Ltd | Professional & scientific | 2025 |
| James Mcgauley Contact Lens Consulting Services Ltd | Health & social care | 2017 |
| James W Young Ltd | Professional & scientific | 2022 |
| Jameson Barrett Luxury Lodges Ltd. | Hospitality | 2025 |
| Jamison Creative Limited | Professional & scientific | 2020 |
| Jardec Ltd | Administrative & support | 2015 |
| Jason Elliott Associates Limited | Professional & scientific | 2013 |
| Jason Elliott Legal Limited | Professional & scientific | 2018 |
| Jasway Limited | Construction | 2011 |
| Jayne Ashleys Limited | Manufacturing | 2025 |
| JB Data Consulting Ltd | Information & communication | 2022 |
| JB Technical Solutions NE Ltd | Professional & scientific | 2024 |
| JC Building & Joinery Ltd | Construction | 2021 |
| JC Quality Management Ltd | Professional & scientific | 2018 |
| JC Residential Projects Ltd | Real estate | 2025 |
| JCL Fire & Security Services Ltd | Administrative & support | 2023 |
| JCM Consultancy Ltd | Information & communication | 2014 |
| JD Outdoor Solutions Ltd | Agriculture & fishing | 2026 |
| JDB Consulting PPM Ltd | Professional & scientific | 2022 |
| Jeera Tandoori Ltd | Hospitality | 2019 |
| JEG Wind Services Ltd | Administrative & support | 2025 |
| Jena Labs Ltd | Information & communication | 2023 |