| Immigration Made Easy Ltd | Professional & scientific | 2005 |
| Immytravels Limited | Transport & logistics | 2025 |
| IMN Cleaners UK Ltd | Administrative & support | 2022 |
| Imogenjane Consultants Limited | Professional & scientific | 2023 |
| Imonsys Limited | Professional & scientific | 2008 |
| Imot and Service Limited | Wholesale & retail | 2000 |
| Impact 3D Signs Limited | Manufacturing | 2000 |
| Impact College of Martial Arts Limited | Education | 2025 |
| Impact Fitness Zone Limited | Arts & recreation | 2010 |
| Imperial Ecommerce Ltd | Wholesale & retail | 2025 |
| Imperial Glass & Glazing Limited | Manufacturing | 1999 |
| Imperial Property Developments (NE) Limited | Real estate | 2019 |
| Imperium Shipping Services Ltd | Transport & logistics | 2012 |
| Implants Local Limited | Information & communication | 2025 |
| Imprint Applications Limited | Manufacturing | 2016 |
| Imprv Ltd | Administrative & support | 2026 |
| Imran Ayoub Solutions Ltd | Professional & scientific | 2018 |
| IMS Risk Management Ltd | Professional & scientific | 2026 |
| Imstel Investments Limited | Wholesale & retail | 2019 |
| Imtcleaning Ltd | Administrative & support | 2025 |
| Imtech Services Limited | Professional & scientific | 2023 |
| Imtiaz Alam Logistics Ltd | Transport & logistics | 2025 |
| IN Cntrl Limited | Manufacturing | 2022 |
| In-Spec Holdings Limited | Real estate | 2019 |
| In-Spec Manufacturing Ltd | Manufacturing | 2013 |
| INA Metals Ltd | Administrative & support | 2020 |
| Inaira Ltd | Professional & scientific | 2025 |
| Indental Practice Limited | Health & social care | 2008 |
| Independence & Mobility Specialists Ltd | Other services | 2020 |
| Independent Methodist Church Limited | Real estate | 2023 |
| Indevah Housing Ltd | Real estate | 2023 |
| Indian Spice and Catering Ltd | Hospitality | 2024 |
| Indian Spice NE Ltd | Hospitality | 2025 |
| Indigo Blue Land & Estates Ltd | Real estate | 2011 |
| Indigo Support Limited | Health & social care | 2018 |
| Individual Solutions NE Ltd | Real estate | 2020 |
| Indus Metal Services Ltd | Wholesale & retail | 2020 |
| Industrial & Community Wind Generation Limited | Energy | 2010 |
| Industrial & Community Wind Generation NO. 2 Limited | Energy | 2012 |
| Industrial and Marine Hydraulics Limited | Manufacturing | 1983 |
| Industrial Motors and Gears Limited | Manufacturing | 2001 |
| Industrial Specialist Services Limited | Manufacturing | 1995 |
| Industrial Technology Systems Limited | Professional & scientific | 1991 |
| Industrial Transformation Partners Ltd | Professional & scientific | 2026 |
| Industro Design Engineering Ltd | Professional & scientific | 2021 |
| Industro Engineering Group Ltd | Professional & scientific | 2021 |
| Industro Engineering Solutions Ltd | Professional & scientific | 2016 |
| Industro Group Limited | Financial services | 2017 |
| Industro Holdings Ltd | Financial services | 2023 |
| Industro Pipetek Ltd | Construction | 2023 |
| Industry 4 YOU Limited | Construction | 2023 |
| Industry Coffee House & Deli Ltd | Wholesale & retail | 2017 |
| Infant Hercules Films Ltd | Information & communication | 2025 |
| Infant Hercules Ltd | Professional & scientific | 2024 |
| Infinite Sage Ltd | Information & communication | 2019 |
| Infinity Retreats Yorkshire Ltd | Construction | 2025 |
| Infiniverde Ltd | Information & communication | 2023 |
| Infosec Data Networks Ltd | Information & communication | 2018 |
| Infosec Nexus Ltd | Information & communication | 2025 |
| Infra Insights Ltd | Professional & scientific | 2025 |
| Infratec Assets Limited | Extraterritorial | 2020 |
| Infratec Investments Limited | Extraterritorial | 2020 |
| Infratec Limited | Extraterritorial | 2023 |
| Infratec Training Limited | Extraterritorial | 2020 |
| Infratec-Uk Limited | Professional & scientific | 2013 |
| Infuselle Ltd | Health & social care | 2025 |
| Ingameuk Limited | Other services | 2018 |
| Ingelby Services Ltd | Administrative & support | 2024 |
| Ingleby Barwick Cricket Club Ltd | Arts & recreation | 2025 |
| Ingleby Barwick Cricket Sports Club Ltd | Arts & recreation | 2026 |
| Ingleby Instrumentation Limited | Manufacturing | 2009 |
| Ingleside Construction NY Ltd | Construction | 2021 |
| Ingleside PM Consultants Ltd | Professional & scientific | 2023 |
| Injaz Contracting Ltd | Wholesale & retail | 2025 |
| INK & Thread Ltd | Wholesale & retail | 2025 |
| INK Events UK Ltd | Administrative & support | 2025 |
| Inn Together Ltd | Hospitality | 2022 |
| Inner Race Ltd | Manufacturing | 2023 |
| Innes Electrical Ltd | Construction | 2024 |
| Innocent Family Holdings LLP | | 2018 |
| Innova Structures Ltd | Professional & scientific | 2025 |
| Innovation Living Limited | Other services | 2016 |
| Innovheat Ltd | Construction | 2023 |
| Insafehands (NE) Ltd | Professional & scientific | 2020 |
| Insight ERP Consultants Limited | Information & communication | 2018 |
| Insight Managed Services Limited | Administrative & support | 2024 |
| Insignia Signs & Graphix Limited | Manufacturing | 2014 |
| Insite People Ltd | Administrative & support | 2023 |
| Inspection & Maintenance Services Ltd | Administrative & support | 2016 |
| Inspection and Integrity Associatone Ltd | Professional & scientific | 2020 |
| Inspection Connection Ltd | Wholesale & retail | 2019 |
| Inspection Quality Ltd | Professional & scientific | 2023 |
| Inspector Snag Ltd | Professional & scientific | 2022 |
| Inspiredprices Ltd | Wholesale & retail | 2026 |
| Inspiredtrading Ltd | Wholesale & retail | 2026 |
| Insta Pump Hire Ltd | Transport & logistics | 2013 |
| Instacargo Ltd | Transport & logistics | 2020 |
| Instacash Raffles Ltd | Arts & recreation | 2026 |
| Instech Limited | Professional & scientific | 2025 |
| Instelect Limited | Professional & scientific | 2007 |