| Horeb Healthcare Solution Ltd | Public administration | 2026 |
| Horeb Shelters Ltd | Real estate | 2026 |
| Horisonbloom Ltd | Real estate | 2025 |
| Horizon Technical Services (UK) Limited | Professional & scientific | 1994 |
| Horizon Travels Ltd | Transport & logistics | 2017 |
| Horseshoe Bridge Enterprises Limited | Professional & scientific | 2014 |
| Horsley Cooper Limited | Wholesale & retail | 2020 |
| Hot Data Consulting Ltd | Information & communication | 2016 |
| Hotality Group Ltd | Financial services | 2019 |
| Hotality Investments Ltd | Real estate | 2020 |
| Hotality IT Solutions Ltd | Information & communication | 2016 |
| Hotality Leisure Ltd | Real estate | 2020 |
| Hound Farm LLP | | 2013 |
| House Alma Ltd | Real estate | 2021 |
| House HR Ltd | Administrative & support | 2026 |
| House of Handsome Ltd | Other services | 2019 |
| House of Mina Investments Ltd | Real estate | 2021 |
| Household Investments Limited | Construction | 2017 |
| Howard Jones Design Ltd | Professional & scientific | 2010 |
| Howdy Darlin' Tattoo Ltd | Other services | 2025 |
| HR Initiatives Limited | Professional & scientific | 2003 |
| HR Print and Design Ltd | Manufacturing | 2011 |
| HTC Roofing Ltd | Construction | 2023 |
| HTW Consultants Limited | Education | 2025 |
| Hub Contracts Limited | Manufacturing | 2024 |
| Hub Kitchens Limited | Construction | 2014 |
| Hub Logistics Limited | Transport & logistics | 2026 |
| Hucker Ltd | Professional & scientific | 2025 |
| Hudscorp Engineering Limited | Professional & scientific | 2020 |
| Hughes Engineering & Support Services Limited | Professional & scientific | 2020 |
| Hughes Syndrome Foundation | Health & social care | 2010 |
| Huma Estates Ltd | Real estate | 2023 |
| Huma Trading Ltd | Wholesale & retail | 2024 |
| Huma Ventures Ltd | Administrative & support | 2026 |
| Hummingbird Salon Ltd | Other services | 2013 |
| Humtum&Sky Ltd | Transport & logistics | 2012 |
| Hungry Chihuahuas Ltd | Wholesale & retail | 2021 |
| Hunjan Property Investments Ltd | Real estate | 2017 |
| Hunt and Watson Property Management LLP | | 2023 |
| Hutchen Enterprises Limited | Hospitality | 2021 |
| Hutt Ltd | Wholesale & retail | 2025 |
| Hutton Bubear Limited | Professional & scientific | 2018 |
| Hutton Bubear Property Consultants Ltd | Professional & scientific | 2021 |
| HXN Consulting Ltd | Information & communication | 2025 |
| Hydroben Ltd | Health & social care | 2023 |
| Hyland Sturdy Ltd | Professional & scientific | 2015 |
| Hypatia Smart Technologies Limited | Professional & scientific | 2013 |
| Hype Photography Limited | Administrative & support | 2006 |
| Hyper Reel Action Ltd | Arts & recreation | 2012 |
| Hyperlid Limited | Manufacturing | 2020 |
| Hyve Solutions Europe Limited | Information & communication | 1988 |
| Hyve Solutions Holding Company Limited | Professional & scientific | 2017 |
| Hyve Solutions UK Limited | Financial services | 2021 |
| I D Coburn & Associates Ltd | Professional & scientific | 2010 |
| I J Tarrant Limited | Energy | 2008 |
| I Q Finance Limited | Financial services | 2002 |
| I S V Software Limited | Information & communication | 2003 |
| I SAY I DO Limited | Wholesale & retail | 2014 |
| I-Fit S&B Ltd | Construction | 2025 |
| I.A.M Systems Limited | Information & communication | 1997 |
| I.C.S. 1989 Limited | Information & communication | 1989 |
| I.K. Tilbury Designs Limited | Professional & scientific | 1989 |
| Iadvisory Ltd | Professional & scientific | 2019 |
| Iaraa Ltd | Construction | 2026 |
| IB Conquest Ltd | Wholesale & retail | 2023 |
| IBC Engineering Ltd | Construction | 2023 |
| Ibimishop Ltd | Wholesale & retail | 2024 |
| IC Safety Consultancy Ltd | Professional & scientific | 2006 |
| ICC Networks Limited | Information & communication | 2006 |
| Ichoose Life Ltd | Other services | 2023 |
| Icol Building Solutions Ltd | Construction | 2019 |
| Ics.Ai Ltd | Information & communication | 2018 |
| IDA Acupuncture Ltd | Health & social care | 2024 |
| IDB Management Systems Services Limited | Administrative & support | 2012 |
| Ideaforge Supply & Services Ltd | Wholesale & retail | 2026 |
| Ideal Paving Limited | Construction | 2019 |
| IDO Cohen Consulting Limited | Information & communication | 2025 |
| Idos Virtual Services Limited | Administrative & support | 2013 |
| Idyll Ltd | Wholesale & retail | 2020 |
| IFC Express Ltd | Construction | 2018 |
| IGB Security Limited | Administrative & support | 2015 |
| IGN Consulting Limited | Professional & scientific | 2020 |
| Igotechsolutions Limited | Information & communication | 2023 |
| Ijaykachief Care Limited | Health & social care | 2025 |
| IJV Aesthetics Limited | Other services | 2022 |
| Ikan Estates Ltd | Real estate | 2025 |
| Ikigai Technologies Ltd | Information & communication | 2022 |
| Ikiru People Limited | Information & communication | 1986 |
| Ikon.Iq Nails UK Ltd | Wholesale & retail | 2019 |
| IL6 Limited | Information & communication | 2016 |
| Ilias Construction & Transport Ltd | Construction | 2024 |
| Ilsley Investments Ltd | Real estate | 2026 |
| IM Marine Advisors Limited | Professional & scientific | 2015 |
| Imagination Design Limited | Professional & scientific | 2007 |
| Imargo Ltd | Wholesale & retail | 2025 |
| IMF Business Solutions Limited | Information & communication | 2007 |
| Imfolozi Limited | Administrative & support | 2022 |
| Imogen Maria Beauty Studio Ltd | Other services | 2015 |
| Imoko Limited | Professional & scientific | 2015 |
| IMP Quality UK Limited | Professional & scientific | 2011 |