| Ignite Health and Wellbeing Limited | Health & social care | 2025 |
| Ignite Health Wellness and Performance Ltd | Health & social care | 2024 |
| Ignite Horizon Shines Ltd | Wholesale & retail | 2025 |
| Ignite Robotics and Coding Ltd | Information & communication | 2024 |
| Ignitex Group Nottingham Ltd | Wholesale & retail | 2025 |
| Ignition Classics Limited | Wholesale & retail | 2020 |
| Ignition Trading Limited | Wholesale & retail | 2024 |
| Ignys Ltd | Professional & scientific | 2017 |
| Igoals Limited | Information & communication | 2006 |
| Igolide Services Ltd | Information & communication | 2014 |
| IGS Entertainment Ltd | Arts & recreation | 2024 |
| IGS Group Holdings Ltd | Financial services | 2025 |
| IH (Topco) Limited | Financial services | 2020 |
| IH Care Service Limited | Health & social care | 2025 |
| Iheart Ltd | Administrative & support | 2012 |
| Ihenterprisess Ltd | Wholesale & retail | 2025 |
| IHM Solutions Ltd | Information & communication | 2022 |
| IHS Global Alliance Limited | Wholesale & retail | 2013 |
| Ihsanix Media Limited | Wholesale & retail | 2026 |
| IHX Ltd | Wholesale & retail | 2025 |
| IIA Digital Ltd | Information & communication | 2013 |
| IIB Crocker Ltd | Professional & scientific | 2022 |
| IIH Oncology Limited | Health & social care | 2024 |
| Iikra Limited | Information & communication | 2017 |
| Iild Ltd | Real estate | 2024 |
| Iimeh Limited | Real estate | 2018 |
| Iitl Limited | Information & communication | 2009 |
| Ijad | Arts & recreation | 1999 |
| IJB Properties Ltd | Real estate | 2020 |
| IJL Precast Limited | Construction | 2025 |
| Ijlee Communications Limited | Arts & recreation | 2017 |
| IJM Beauty and Aesthetics Training Academy Ltd | Other services | 2023 |
| IJV Properties Limited | Real estate | 2023 |
| IK EYE Care Ltd | Wholesale & retail | 2023 |
| IK Group of Companies Limited | Information & communication | 2023 |
| IKB Consultancy Ltd | Professional & scientific | 2018 |
| Ikbal Cleaning Ltd | Professional & scientific | 2020 |
| Ikconn Medical Healthcare Limited | Administrative & support | 2018 |
| Ikconn Transport Ltd | Transport & logistics | 2024 |
| Ikegrid Ltd | Energy | 2026 |
| Ikenna Promotions Ltd | Professional & scientific | 2023 |
| Ikeonic Ltd | Financial services | 2024 |
| Ikes Logistics Company Ltd | Transport & logistics | 2026 |
| Ikesons Ltd | Wholesale & retail | 2025 |
| Ikoe Investments Unlimited | Financial services | 2022 |
| Ikon (GBR) Limited | Wholesale & retail | 2016 |
| Ikon International Ltd | Hospitality | 2016 |
| Ikonic Services UK Ltd | Professional & scientific | 2015 |
| Ikram Consultancy Ltd | Professional & scientific | 2023 |
| IKT Consulting Limited | Professional & scientific | 2020 |
| Ikusawepfx Ltd | Administrative & support | 2019 |
| IL Homelands Limited | Real estate | 2020 |
| IL Lordship Lane Limited | Real estate | 2021 |
| IL Melton Lane Limited | Construction | 2023 |
| IL Storage and Printing Limited | Other services | 2024 |
| IL Wilford Lane Limited | Construction | 2020 |
| Iliad Music Ltd | Arts & recreation | 2014 |
| Iliffe Poulter Accountancy & Taxation Services Ltd | Professional & scientific | 2016 |
| Iliffe Poulter Ltd | Professional & scientific | 2010 |
| Ilixa Limited | Information & communication | 2009 |
| Ilkeston Carpets Ltd | Wholesale & retail | 2017 |
| Ilkeston Eyecare Limited | Health & social care | 1990 |
| Ilkeston Plumbing & Heating Supplies Limited | Wholesale & retail | 1995 |
| Ilkeston Power Limited | Energy | 2015 |
| Ilkeston Road Car Wash Ltd | Administrative & support | 2025 |
| Ilkeston Road Convenience Store Limited | Wholesale & retail | 2023 |
| Ilkeston Self Storage Limited | Real estate | 2016 |
| Ilkeston Trading Limited | Other services | 2013 |
| Illsley Films and Production Limited | Information & communication | 2021 |
| Illume Casting Ltd | Administrative & support | 2023 |
| Illuminate Education C.I.C. | Education | 2023 |
| Illuminous Consulting Ltd | Professional & scientific | 2014 |
| ILLUSTR8 Design & Marketing Limited | Information & communication | 2005 |
| Illyria Estates Limited | Real estate | 2025 |
| ILN Technology Solutions Ltd | Information & communication | 2023 |
| Iloyalty Technology Limited | Wholesale & retail | 2014 |
| ILS22 Ltd | Education | 2020 |
| ILT Community College C.I.C. | Education | 2012 |
| ILU Trader Ltd | Wholesale & retail | 2018 |
| Iluminesia Limited | Construction | 2012 |
| Ilyas Consulting Services Limited | Health & social care | 2015 |
| Ilyas Takeaway Ltd | Hospitality | 2025 |
| IM Axle Specialists Limited | Manufacturing | 2012 |
| IM Global Group Holdings Limited | Financial services | 2013 |
| IM Legal Advisors Limited | Professional & scientific | 2024 |
| Imaan Pharma Ltd | Health & social care | 2009 |
| Image Creators Ltd | Professional & scientific | 2017 |
| Image Hair and Beauty Ltd | Other services | 2015 |
| Image Machine Limited | Professional & scientific | 2006 |
| Image Pvc-U Systems Ltd | Construction | 2009 |
| Imagen Ltd | Administrative & support | 2025 |
| Imagerelease Ltd | Information & communication | 2025 |
| Imagikit CIC | Education | 2025 |
| Imagimont Ltd | Professional & scientific | 2019 |
| Imaginasia (UK) Limited | Wholesale & retail | 2014 |
| Imaginative Creation Limited | Agriculture & fishing | 2025 |
| Imagine Avenue Ltd | Education | 2022 |
| Imagine Living Here Limited | Real estate | 2024 |
| Imagine-Nation Ltd | Arts & recreation | 2025 |
| Imaging-Solutions-Ir Ltd | Health & social care | 2018 |