| HRS Assets Limited | Real estate | 2025 |
| Hrxoris Ltd | Wholesale & retail | 2023 |
| Hrzn Distribution Ltd | Wholesale & retail | 2024 |
| HS Property Developers Ltd | Construction | 2019 |
| HSR Construction Ltd | Construction | 2026 |
| HSZ Limited | Information & communication | 2011 |
| HT Partners Ltd | Other services | 2025 |
| Hubforth International Limited | Manufacturing | 2018 |
| Hudson Chauffeur Cars Limited | Transport & logistics | 2012 |
| Huevolt Technologies Limited | Information & communication | 2024 |
| Huge Network Limited | Transport & logistics | 2024 |
| HUI Tong International Trading Limited | Hospitality | 2018 |
| HUI Tong Properties Management Ltd | Real estate | 2023 |
| Hui-Ying UK Ltd | Financial services | 2024 |
| Huisheng Ltd | Health & social care | 2014 |
| Hummingbird Property Services Ltd | Real estate | 2021 |
| Huong Trinh Limited | Hospitality | 2023 |
| HY Powerflex Ltd | Wholesale & retail | 2025 |
| Hybrid Event Solutions Ltd | Information & communication | 2021 |
| Hyperion Cybersecurity Limited | Information & communication | 2018 |
| Hyphen Information Technology Limited | Information & communication | 2000 |
| Hythe Road Studio Limited | Information & communication | 2025 |
| HZ Cars London Limited | Wholesale & retail | 2024 |
| I 7 (UK) Ltd | Wholesale & retail | 2013 |
| I-Parcel Limited | Transport & logistics | 2010 |
| Iagp Technology Solutions Limited | Information & communication | 2021 |
| IAI Services Ltd | Information & communication | 1997 |
| Iamflow CIC | Education | 2025 |
| Ibconnect UK Limited | Construction | 2024 |
| IC Biomedical UK Limited | Manufacturing | 2020 |
| Icas Investments Ltd | Financial services | 2019 |
| Icon Accessories Limited | Wholesale & retail | 2014 |
| Iconnectxion Private Ltd | Information & communication | 2022 |
| Idahoan UK Ltd | Manufacturing | 2018 |
| Ifm-Fm Limited | Extraterritorial | 2010 |
| IFS Finance UK Limited | Financial services | 2022 |
| IFS Ultimo Ltd | Information & communication | 2018 |
| Ignition Events Ltd | Administrative & support | 2019 |
| Ilie Aerotrucks Ltd | Transport & logistics | 2026 |
| IM Property Surveyors Ltd | Wholesale & retail | 2020 |
| IMC Builders Ltd | Construction | 2026 |
| Imperial Holdings Limited | Professional & scientific | 2005 |
| Imperial Integrated Systems Limited | Construction | 2021 |
| Imperial Palace Motors Limited | Wholesale & retail | 2020 |
| Impetro Continental Services Ltd | Wholesale & retail | 2020 |
| Implementix Ltd | Information & communication | 2025 |
| IN Time Movements Limited | Transport & logistics | 1999 |
| Incenium Limited | Professional & scientific | 2018 |
| Inden Ltd | Real estate | 2020 |
| Inden Private Ltd | Information & communication | 2022 |
| Independent Profit Consultants Limited | Real estate | 2003 |
| Indian Homemade Ltd | Hospitality | 2021 |
| Indiedoers Ltd | Information & communication | 2022 |
| Indipol Limited | Information & communication | 2011 |
| Individual Properties Limited | Construction | 1961 |
| Indo Italian Fusion Ltd | Hospitality | 2024 |
| Industrial and Financial Systems, IFS UK Ltd | Information & communication | 1996 |
| Infradaw Commercial Services Ltd | Professional & scientific | 2023 |
| Initiative Vortex Limited | Professional & scientific | 2015 |
| INKOR9 Ltd | Wholesale & retail | 2017 |
| Inner Light C.I.C. | Education | 2025 |
| Innotech Construction Ltd | Construction | 2024 |
| Innovative ERP Ltd | Information & communication | 2010 |
| Innovative Support Ltd | Health & social care | 2019 |
| Inodesign Kitchen and Bedroom Ltd | Manufacturing | 2026 |
| Inova Guarantee Services Ltd | Administrative & support | 2024 |
| Inova Management International Ltd | Professional & scientific | 2016 |
| Inova Management Limited | Other services | 2022 |
| Inse Photography Ltd | Professional & scientific | 2024 |
| Insight Consulting Engineers Limited | Professional & scientific | 2024 |
| Inspired Interiors London Limited | Construction | 2004 |
| Institute of Biodynamic Medicine Limited | Education | 1989 |
| Integra Biosciences Limited | Professional & scientific | 2013 |
| Intelance Digital Enablement Services Ltd | Information & communication | 2017 |
| Intelia Limited | Information & communication | 2025 |
| Intellect Developments Ltd | Construction | 2021 |
| Intercarry Limited | Transport & logistics | 2016 |
| Intergalactico Ltd | Transport & logistics | 2020 |
| Interlaw Limited | Professional & scientific | 1982 |
| International Accounts Limited | Professional & scientific | 2025 |
| International AI Limited | Information & communication | 2025 |
| International Audio Visual Academy Limited | Other services | 2025 |
| International Audio Visual Limited | Construction | 2024 |
| International CK Inmods Limited | Construction | 2025 |
| International Lithium UK Ltd | Administrative & support | 2020 |
| International Property Group Limited | Real estate | 2026 |
| International PT Jacked Attire Limited | Education | 2025 |
| International Tech Collect Limited | Water & waste | 2025 |
| Intimate Financial Services Ltd | Financial services | 2018 |
| Intro DY Ltd | Construction | 2023 |
| Invest in Growth Limited | Real estate | 2018 |
| Invictus Associates Ltd | Administrative & support | 2010 |
| Iqronix Ltd | Information & communication | 2025 |
| Iron Asylum Ltd | Wholesale & retail | 2019 |
| Isaac Grill Ltd | Hospitality | 2018 |
| Isaac Trading Ltd | Wholesale & retail | 2016 |
| Isher and Jeonah Properties Ltd | Real estate | 2021 |
| Isiy Properties Ltd | Real estate | 2022 |
| Iskill Tech Ltd | Information & communication | 2021 |
| Issar Asset Management Ltd | Transport & logistics | 2024 |