| Hudor Haulage Ltd | Transport & logistics | 2025 |
| Human Touch Ambulance Limited | Transport & logistics | 2009 |
| Hunger Villa Ltd | Hospitality | 2026 |
| Hungrilla Limited | Hospitality | 2024 |
| Hungry Bear Food Ltd | Manufacturing | 2021 |
| Hunters' Overlook Limited | Financial services | 2013 |
| Huntress Promotional Merchandise Limited | Professional & scientific | 2022 |
| Hurst Farm Investments Ltd | Real estate | 2024 |
| Huttoft Bank Management Company Limited | Hospitality | 1984 |
| Hwandi Limited | Health & social care | 2013 |
| Hybrid Air Conditioning Ltd | Construction | 2024 |
| Hydro App Systems Ltd | Wholesale & retail | 2016 |
| Hygieia Collective Ltd | Hospitality | 2025 |
| Hynes K9 Ltd | Administrative & support | 2026 |
| Hypestage Limited | Professional & scientific | 2025 |
| I & N Fabrication Limited | Manufacturing | 2006 |
| I & N Property Limited | Wholesale & retail | 2011 |
| I & N Site Servicing Limited | Construction | 2006 |
| I - Sight Technology Ltd | Information & communication | 2021 |
| I Falconer Plant Limited | Manufacturing | 2015 |
| I FUN Mansfield Limited | Arts & recreation | 2025 |
| I G Waste Management Ltd | Water & waste | 2025 |
| I P Results Limited | Extraterritorial | 2010 |
| I SAW IT First Limited | Wholesale & retail | 2016 |
| I V Trading Ltd | Wholesale & retail | 2024 |
| I Wood Train Ltd | Education | 2024 |
| I&C PUB Management Company Ltd | Hospitality | 2024 |
| I&U Property Ltd | Real estate | 2025 |
| I&U Trading Ltd | Wholesale & retail | 2025 |
| I-Em SAT Ltd | Information & communication | 2019 |
| I-Sourcer Limited | Professional & scientific | 2015 |
| I. Aldridge Limited | Health & social care | 2013 |
| I.M.A.A Mosor Ltd | Transport & logistics | 2022 |
| IAN Hurst (Properties) Limited | Construction | 1981 |
| IAN James Thompson Ltd | Financial services | 2025 |
| IAN Kells Ltd | Administrative & support | 2025 |
| IAN Smith Electrical Limited | Construction | 1986 |
| IAT Solutions Ltd | Other services | 2020 |
| Ibanez SL Ltd | Hospitality | 2025 |
| Ibex Motorhomes Ltd | Wholesale & retail | 2022 |
| IBO Hair Studio Ltd | Other services | 2023 |
| IBS Services Ltd | Construction | 2020 |
| Ibtex Ltd | Professional & scientific | 2023 |
| ICD Property Maintenance Ltd | Construction | 2019 |
| Ice Cream Kiosks Limited | Hospitality | 2013 |
| Ice Cream Parlours Limited | Hospitality | 2013 |
| ICM North Ltd | Arts & recreation | 2025 |
| ICM South Ltd | Arts & recreation | 2022 |
| Iconic Bride Limited | Wholesale & retail | 2014 |
| ID Fire Solutions Ltd | Public administration | 2021 |
| IDC HGV Services Ltd | Hospitality | 2016 |
| Ideacube Ltd | Professional & scientific | 2016 |
| Ideer Communications Limited | Information & communication | 2009 |
| Idhika Ltd | Wholesale & retail | 2022 |
| Idle, Torne and Trent Water Abstractors Group CIC | Agriculture & fishing | 2026 |
| Idre Homes Limited | Real estate | 2020 |
| Ifeline Precision Engineering Ltd | Professional & scientific | 2006 |
| Ifernco Ltd | Health & social care | 2020 |
| IFT Services Limited | Agriculture & fishing | 2000 |
| Ighw Limited | Manufacturing | 2001 |
| IGK Traders Limited | Real estate | 2014 |
| Iimbe UK Ltd | Information & communication | 2025 |
| IL Rosso Limited | Hospitality | 2008 |
| Ilkan's Cleaning Ltd | Administrative & support | 2020 |
| Iluaobe Healthcare Ltd | Health & social care | 2025 |
| Image Apparel Ltd | Wholesale & retail | 2013 |
| Image Real Estate Company Ltd | Real estate | 2019 |
| Imagine Arts and Other Senses Ltd | Education | 2022 |
| Impact Golf Performance Limited | Wholesale & retail | 2020 |
| Impact Management Group Ltd | Professional & scientific | 2026 |
| Imperial Drives Limited | Construction | 2006 |
| Imperial Personnel Limited | Administrative & support | 2020 |
| Imperial Safety Solutions Limited | Construction | 2016 |
| Impex Customs Ltd | Transport & logistics | 2021 |
| Impression Residential Limited | Real estate | 2014 |
| Improvahome Ltd | Construction | 2021 |
| Impulse Electrical Installations Ltd | Construction | 2023 |
| Imrtl Ltd | Wholesale & retail | 2025 |
| IMS Promotions Ltd | Professional & scientific | 2025 |
| Inbisense Ltd | Professional & scientific | 2022 |
| Inception Associates Ltd | Professional & scientific | 2009 |
| Inclusion Specialist Property Management Services Ltd | Real estate | 2023 |
| Incubitu Ltd | Professional & scientific | 2021 |
| Indefinite Ltd | Hospitality | 2025 |
| Indi Cars Ltd Ltd | Wholesale & retail | 2025 |
| Indibuild & Development Ltd | Construction | 2024 |
| Indie Property Services Limited | Real estate | 2024 |
| Indigo BD Cuisine Limited | Hospitality | 2024 |
| Indigo Fusion Takeaway Limited | Hospitality | 2023 |
| Indigo Masala House Ltd | Hospitality | 2026 |
| Indoor Design 4U Ltd | Construction | 2021 |
| Indulgence Time Ltd | Wholesale & retail | 2021 |
| Industrial Strength UK Limited | Professional & scientific | 2016 |
| Infinite AV Ltd | Manufacturing | 2013 |
| Infinite Blue Consulting Limited | Administrative & support | 2017 |
| Infinity Heat Pumps Limited | Construction | 2023 |
| Infotech Direct Limited | Information & communication | 2006 |
| Infotech Nexcloud Limited | Information & communication | 2025 |
| Infused Electrical Contractors Limited | Construction | 2016 |
| Infused Property Ltd | Households | 2023 |