| Hopeview Social Care Ltd | Health & social care | 2026 |
| Hopkins Property Development Ltd | Real estate | 2023 |
| Horizon Assured Ltd | Health & social care | 2024 |
| Horizonai Limited | Information & communication | 2023 |
| Horocon Global Sourcing Limited | Wholesale & retail | 2025 |
| Horseman Ltd | Wholesale & retail | 2025 |
| Hospitality Connection Ltd | Administrative & support | 2022 |
| Hot Pocket Limited | Other services | 2013 |
| Hotel Dynamics Services UK Limited | Administrative & support | 2002 |
| Hothouse Publishing Ltd | Information & communication | 2018 |
| Houghton Brown Enterprises Limited | Agriculture & fishing | 1976 |
| Hougles & Dougles Ltd | Transport & logistics | 2024 |
| House of Kerry Ltd | Real estate | 2026 |
| House of Mystery Ltd | Wholesale & retail | 2021 |
| HOW DO I Helpdesk Ltd | Information & communication | 2023 |
| Howard France Surveys Ltd | Other services | 2019 |
| Howell Project Management Limited | Professional & scientific | 2026 |
| Howie Stewart Homes Limited | Construction | 2001 |
| Howitts Limited | Wholesale & retail | 1914 |
| Howper 760 Limited | Financial services | 2014 |
| Hoyte & H Maintenance Limited | Construction | 2025 |
| Hoyte Maintenance Limited | Construction | 2020 |
| HRT Consulting Limited | Professional & scientific | 2025 |
| HSB Real Estate LDN EST 2025 LLP | | 2025 |
| HSS Property Group Ltd | Real estate | 2023 |
| Hubi & Mati Mechanics Ltd | Wholesale & retail | 2014 |
| Hubker Limited | Real estate | 2021 |
| Hudson James Consulting Limited | Professional & scientific | 2026 |
| HUE Sprayworks Ltd | Construction | 2025 |
| Hughes Welding Solutions Ltd | Construction | 2013 |
| Hugo NEL Psychology Ltd | Health & social care | 2026 |
| Human Consulting Limited | Administrative & support | 2022 |
| Humbamak Limited | Professional & scientific | 2022 |
| Hungrybuff Co Ltd | Information & communication | 2023 |
| Huntrans Ltd | Construction | 2016 |
| Hurley Financial Services Limited | Professional & scientific | 2013 |
| Huxloe Logistics Ltd | Transport & logistics | 2009 |
| Hvss Group Limited | Financial services | 2021 |
| HY Building Design Ltd | Professional & scientific | 2020 |
| Hydra-Test Limited | Professional & scientific | 2017 |
| Hydroware (UK) Limited | Manufacturing | 2013 |
| Hygeia Pilates and Wellness Limited | Education | 2024 |
| Hyperian Properties Ltd | Real estate | 1999 |
| I - SUB Limited | Manufacturing | 2001 |
| I Love My Business Ltd | Wholesale & retail | 2023 |
| I M Kelly Automotive Limited | Manufacturing | 2018 |
| I M Kelly Holdings Limited | Professional & scientific | 2014 |
| I M Kelly R & a Ltd | Manufacturing | 1994 |
| I Wooten Ltd | Transport & logistics | 2011 |
| I&I BRB Ltd | Wholesale & retail | 2023 |
| I.M Trans Ltd | Transport & logistics | 2014 |
| I.M. Kelly Limited | Manufacturing | 1979 |
| I.O.Family Ltd | Transport & logistics | 2024 |
| I.T.S. Transport (UK) Limited | Transport & logistics | 2002 |
| I2COMPLY Limited | Information & communication | 2011 |
| I2D2 Limited | Information & communication | 2005 |
| I4 Data Protection Limited | Information & communication | 2012 |
| Iainmack Limited | Hospitality | 2025 |
| IAN Chown Accountancy and Consultancy Ltd | Professional & scientific | 2022 |
| IAN Dickerson Funding Consultancy Limited | Professional & scientific | 2024 |
| IAN Ellison Consulting Ltd | Education | 2019 |
| IAN Rhodes Limited | Administrative & support | 2021 |
| IB Airsports Ltd | Professional & scientific | 2026 |
| Ibec Limited | Agriculture & fishing | 2000 |
| Ibond Limited | Administrative & support | 2014 |
| Ibyte Apps Limited | Information & communication | 2015 |
| Ican Talk Ltd | Other services | 2009 |
| Iccm (Training) Limited | Education | 2001 |
| Icecape Limited | Construction | 1999 |
| Iceman Global Services Limited | Wholesale & retail | 2025 |
| Iconic Accessories Limited | Administrative & support | 2012 |
| Iconic Motorsport Limited | Wholesale & retail | 2014 |
| ICV Construction Ltd | Construction | 2013 |
| IDA20 Ltd | Wholesale & retail | 2020 |
| Idandanov Ltd | Transport & logistics | 2020 |
| Ideal Host Ltd | Hospitality | 2023 |
| Ideal Profile Limited | Health & social care | 2011 |
| Ifeangel Limited | Real estate | 2018 |
| Ifoodsuk Ltd | Wholesale & retail | 2022 |
| Ignite Vape Limited | Wholesale & retail | 2025 |
| IGO Safety Consultancy Limited | Public administration | 2018 |
| Igor Ciobanu Ltd | Transport & logistics | 2026 |
| IK Omkar Enterprise Limited | Real estate | 2017 |
| Ikall Limited | Professional & scientific | 2014 |
| Ikars of Kettering Limited | Wholesale & retail | 2015 |
| IKD Interiors Limited | Manufacturing | 2014 |
| Ikikit Ltd | Wholesale & retail | 2022 |
| Ilay Property Ltd | Real estate | 2026 |
| Ilitone Sound Ltd | Information & communication | 2025 |
| ILP (Holdings) Limited | Financial services | 2013 |
| Image Aesthetics Limited | Health & social care | 2013 |
| Image Property Services (Kettering) Ltd | Construction | 2012 |
| IMJ Ltd | Construction | 2023 |
| IMK Automotive Limited | Manufacturing | 2000 |
| IML Carpentry Limited | Construction | 2016 |
| Immix Freehold Ltd | Real estate | 2022 |
| Impact Education Ltd | Education | 2024 |
| Impact Professional Service Ltd | Health & social care | 2023 |
| Impactre Limited | Other services | 2016 |
| Impec Real Estate Limited | Real estate | 2018 |