| Islebest Limited | Manufacturing | 1991 |
| Ismail Invests Ltd | Professional & scientific | 2023 |
| Ismartsecurity Limited | Administrative & support | 2014 |
| Ismeta International Limited | Hospitality | 2021 |
| Ismmik Limited | Wholesale & retail | 2023 |
| Isny Limited | Real estate | 2023 |
| Isoare Ltd | Construction | 2015 |
| Isokun House Limited | Real estate | 2024 |
| Isos Barbers Ltd | Other services | 2023 |
| Issa Travel Limited | Transport & logistics | 2018 |
| IST Choice Builders Ltd | Construction | 2025 |
| Istanbul Barber Luton Ltd | Other services | 2023 |
| Istanbul Barber Salon Ltd | Other services | 2022 |
| Istanbul Foods Limited | Wholesale & retail | 2021 |
| Istruct Consultants Limited | Professional & scientific | 2013 |
| Istruct Investments Ltd | Real estate | 2018 |
| Isufaj Services Ltd | Construction | 2025 |
| Iszu Holdings Ltd | Financial services | 2023 |
| IT Builds LAB Limited | Water & waste | 2026 |
| IT Construct Limited | Construction | 2023 |
| IT First Solutions Group Limited | Information & communication | 2024 |
| IT Global Solutions Ltd | Information & communication | 2026 |
| IT Operations Ltd | Information & communication | 2018 |
| IT Proficiency Limited | Information & communication | 2018 |
| IT Research Tehnology Ltd | Information & communication | 2025 |
| IT Resource-Consulting Limited | Professional & scientific | 2015 |
| IT Services 365 Ltd | Information & communication | 2019 |
| IT Support Software Limited | Information & communication | 2017 |
| IT Visionists Ltd. | Information & communication | 2013 |
| It's HER Kitchen Ltd | Hospitality | 2018 |
| Itai's Hair Studio Limited | Professional & scientific | 2002 |
| Italian Bangladeshi Cultural Association Luton Ltd | Health & social care | 2024 |
| Italian Coffee Ventures Ltd | Wholesale & retail | 2022 |
| Italian JOB Ltd | Wholesale & retail | 2023 |
| ITALY2GO Ltd | Hospitality | 2022 |
| Itas Group Kent Limited | Hospitality | 2025 |
| Itas Group Limited | Professional & scientific | 2025 |
| ITD Training Ltd | Education | 2015 |
| Itdefender Ltd | Wholesale & retail | 2017 |
| ITE Construction Limited | Construction | 2022 |
| Itech Consultancy Services Ltd | Information & communication | 2013 |
| Itech Logistics Ltd | Transport & logistics | 2017 |
| Itech Travel Ltd | Transport & logistics | 2017 |
| Itechoo Group Ltd | Wholesale & retail | 2025 |
| Iteraflow Delivery Ltd | Information & communication | 2026 |
| ITF Energy LLP | | 2024 |
| Ithaca Catering Company Ltd | Hospitality | 2021 |
| Itlytical Ltd | Information & communication | 2022 |
| ITN Trans Ltd | Transport & logistics | 2025 |
| Itnetworkingcouk Ltd | Information & communication | 2012 |
| Itorolux Ltd | Professional & scientific | 2023 |
| Itrust Care Services Ltd | Real estate | 2016 |
| Itrust Housing Ltd | Real estate | 2021 |
| ITS ALL About CRM Ltd | Professional & scientific | 2014 |
| Itsharp Ltd | Information & communication | 2023 |
| Itsolutionsedge Ltd | Information & communication | 2025 |
| It’S ALL About the Taste Ltd | Hospitality | 2024 |
| IU Auto House Ltd | Wholesale & retail | 2024 |
| Iucon Ltd | Construction | 2015 |
| IUH Guard Ltd | Administrative & support | 2026 |
| IUL Advertising Ltd | Professional & scientific | 2017 |
| Iuliantrans Ltd | Transport & logistics | 2026 |
| Iulimus Ltd | Construction | 2023 |
| Iurem Ltd | Construction | 2020 |
| Iussn Ltd | Wholesale & retail | 2017 |
| IV Garage Ltd | Wholesale & retail | 2024 |
| IV Travel Limited | Administrative & support | 2019 |
| Iva-Consults & Healthcare Services Limited | Health & social care | 2021 |
| IVK Ltd | Wholesale & retail | 2013 |
| Ivod Ltd | Information & communication | 2016 |
| Ivoryluxe Event Ltd | Administrative & support | 2026 |
| IVP Services Ltd | Information & communication | 2022 |
| Ivygrove Furniture Ltd | Wholesale & retail | 2024 |
| IW Financial Services Ltd | Professional & scientific | 2024 |
| IWA (HH) Limited | Construction | 2015 |
| Iwater Inc Ltd | Manufacturing | 2017 |
| IX Electrical Ltd | Construction | 2021 |
| Ixeek Healthcare Ltd | Health & social care | 2026 |
| Ixeek Homes Ltd | Real estate | 2024 |
| IZ Properties Limited | Real estate | 2020 |
| IZ Transport Limited | Transport & logistics | 2018 |
| IZA Automart Ltd | Wholesale & retail | 2021 |
| Izabella Treats Ltd | Manufacturing | 2022 |
| Izdihar International Limited | Information & communication | 2026 |
| Izvori Ltd | Construction | 2022 |
| Izzah INK Ltd | Wholesale & retail | 2025 |
| Izzard Roofing Services Ltd | Construction | 2005 |
| Izze Online Limited | Wholesale & retail | 2021 |
| Izztrims Ltd | Other services | 2025 |
| J & Macaulays Tyre Services Ltd | Wholesale & retail | 2025 |
| J & P Properties (UK) Limited | Construction | 2014 |
| J & PL Properties Limited | Hospitality | 2012 |
| J & Sons Auto Repairs Ltd | Wholesale & retail | 2023 |
| J & T Hull Limited | Real estate | 2025 |
| J & Z Limited | Wholesale & retail | 2015 |
| J a Cuts Ltd | Other services | 2022 |
| J Accommodation Ltd | Real estate | 2021 |
| J ALI Exec Travel Ltd | Transport & logistics | 2023 |
| J and M Commercial and Domestic Cleaning Limited | Administrative & support | 2011 |
| J and S Bathrooms Limited | Wholesale & retail | 2014 |