| HULK2PSL Ltd | Information & communication | 2023 |
| Hulme-Lowe Ventures Ltd | Wholesale & retail | 2024 |
| Hulton Street Freehold Limited | Real estate | 2026 |
| Human Made Things Ltd | Professional & scientific | 2026 |
| Human Spirit Drinks Co Ltd | Manufacturing | 2024 |
| Humberhill Pheonix Limited | Information & communication | 2020 |
| Hunja Capital Limited | Financial services | 2026 |
| Huntswood Properties (NO. 2) Ltd | Professional & scientific | 2007 |
| Hurst Fashion Ltd | Real estate | 2016 |
| Hustle Health Bars Ltd | Hospitality | 2024 |
| Huxley Anderson Limited | Wholesale & retail | 2024 |
| HW Enterprise Limited | Administrative & support | 2015 |
| HW Investment Holdings Ltd | Financial services | 2023 |
| HWT Roofing Ltd | Construction | 2025 |
| Hydes' Brewery Limited | Manufacturing | 1912 |
| Hydra Business Ltd | Wholesale & retail | 2022 |
| Hydramatics (NW) Limited | Manufacturing | 2018 |
| Hydrolife Ltd | Wholesale & retail | 2021 |
| Hypertech Consulting Limited | Information & communication | 2026 |
| HZM Estates Ltd | Real estate | 2025 |
| I & E Advisory Ltd | Professional & scientific | 2025 |
| I & W Estates Limited | Real estate | 2024 |
| I Apartments Limited | Real estate | 2013 |
| I Go 4 Ltd. | Financial services | 2004 |
| I Henig Ltd | Real estate | 2026 |
| I&Amalia Ltd | Transport & logistics | 2020 |
| I-Bpo Group Ltd | Administrative & support | 2024 |
| I-Bpo UK Ltd | Administrative & support | 2025 |
| I-Link Ltd | Manufacturing | 2025 |
| I-Waste Limited | Administrative & support | 2010 |
| I.A.S. Body Shop Supplies Ltd | Wholesale & retail | 2008 |
| I2I Pipelines Ltd | Professional & scientific | 2013 |
| Iaayh the Bulls Head Limited | Hospitality | 2025 |
| Iaayh the Pollards Inn Ltd | Hospitality | 2026 |
| Ibasco Ltd | Other services | 2020 |
| Ibco Holdings Limited | Real estate | 2024 |
| Ibeto Ltd | Hospitality | 2003 |
| Ibex News Limited | Information & communication | 2025 |
| Ibiba Consulting Ltd | Administrative & support | 2022 |
| Ibitrax Limited | Information & communication | 2023 |
| Ibmdl Limited | Information & communication | 2025 |
| IBO Ladies in Diaspora AID (Ibda) C.I.C. | Education | 2021 |
| Icatch Limited | Professional & scientific | 2019 |
| Ice Teaching LLP | | 2014 |
| Icemask Ltd | Manufacturing | 2011 |
| ICM Consulting Ltd | Professional & scientific | 2011 |
| Icon International Group Limited | Wholesale & retail | 2019 |
| Iconiq Marketing Ltd | Professional & scientific | 2023 |
| Icross Ltd | Wholesale & retail | 2023 |
| ICW Property Management Ltd | Real estate | 2022 |
| ID DBS Holdings Ltd | Real estate | 2025 |
| ID Medical Supply Ltd | Wholesale & retail | 2021 |
| Idol (UK) Ltd | Wholesale & retail | 2012 |
| Idrive MCR Ltd | Wholesale & retail | 2024 |
| IDS Lettings Manchester Limited | Real estate | 2025 |
| Idyllseason Ltd | Professional & scientific | 2021 |
| Iesp Staffing Solutions Limited | Extraterritorial | 2023 |
| Iexcell Solutions Ltd | Information & communication | 2017 |
| IF Sama Ltd | Hospitality | 2020 |
| Ifeatures Limited | Arts & recreation | 2009 |
| Ifly Consult Limited | Professional & scientific | 2020 |
| IG London Properties 2 Limited | Real estate | 2020 |
| Ignite Bidco Limited | Professional & scientific | 2024 |
| Ignite Global Partners Ltd | Professional & scientific | 2023 |
| Ignite Midco Limited | Professional & scientific | 2024 |
| Ignite Topco Limited | Professional & scientific | 2024 |
| IGO4 Partners Limited | Financial services | 2008 |
| IGO4SOLUTIONS Limited | Professional & scientific | 2011 |
| IGT (UK 1) Limited | Arts & recreation | 2003 |
| IGT (UK 2) Limited | Arts & recreation | 2000 |
| Igt-Uk Gaming Limited | Administrative & support | 2002 |
| Igt-Uk Group Limited | Manufacturing | 2005 |
| Igud Rabbonim Ltd | Professional & scientific | 2006 |
| Ihtisham Hassan Ltd | Wholesale & retail | 2025 |
| Iinvnt Ltd | Information & communication | 2024 |
| IJ Motor Services Ltd | Wholesale & retail | 2018 |
| Ijak Ltd | Real estate | 2025 |
| IJM Software Limited | Information & communication | 2025 |
| IK ENG Ltd | Professional & scientific | 2026 |
| Iktara Ltd | Real estate | 2024 |
| ILC Holdings Ltd | Professional & scientific | 2025 |
| Ilimart Limited | Manufacturing | 1990 |
| ILÉ Àdùn Ltd | Hospitality | 2026 |
| Image Making Support Services Limited | Administrative & support | 2025 |
| Image Salford Limited | Manufacturing | 2016 |
| Image Stationery Limited | Wholesale & retail | 2023 |
| Imagination Clothing Ltd | Wholesale & retail | 1996 |
| Imajek BI Consulting Limited | Information & communication | 2016 |
| Imomentum Ltd | Professional & scientific | 2023 |
| Impact Investment Management Limited | Financial services | 2021 |
| Impact Training (UK) Ltd | Education | 2002 |
| Impact Training Academy Limited | Real estate | 2023 |
| Impactworks Ltd. | Professional & scientific | 1997 |
| Impassive Ltd | Financial services | 2023 |
| Imperial Swanpark Limited | Real estate | 2013 |
| Imperium Security Group Limited | Administrative & support | 2018 |
| Import Village Limited | Wholesale & retail | 2021 |
| Impress Estates Holdings Limited | Other services | 2024 |
| Impress Estates Properties Limited | Other services | 2024 |
| Impresse Ltd | Wholesale & retail | 2025 |