| Holistic Being Ltd | Extraterritorial | 2024 |
| Holistic Transformation Ltd | Administrative & support | 2024 |
| Hollykan Events Ltd | Administrative & support | 2024 |
| Home Farm Boulston Management Company Ltd | Real estate | 2023 |
| Homes FUD Ltd | Wholesale & retail | 2025 |
| Honeyborough Construction Limited | Construction | 2015 |
| Honeylicious Limited | Manufacturing | 2019 |
| Hopintolife Ltd | Extraterritorial | 2024 |
| Horgan Concrete Precast Ltd | Manufacturing | 2025 |
| Horgan Timber Systems Ltd | Construction | 2023 |
| Horizon Consulting & Media Ltd | Administrative & support | 2025 |
| Horns Lane Management Limited | Households | 2020 |
| Hotel Mariners Limited | Hospitality | 1983 |
| Hotel Planning Limited | Professional & scientific | 2011 |
| Hotelnut Limited | Hospitality | 2014 |
| Hotelpack Ltd | Administrative & support | 1988 |
| Hotnikas Alliance PC | | 2020 |
| Hottipass Service Station | Wholesale & retail | 2006 |
| Houndiscombe Estates Limited | Construction | 2019 |
| Hroct Technology Ltd | Wholesale & retail | 2021 |
| HSH Skyscraper Ltd | Administrative & support | 2024 |
| Hub of Possibility Ltd | Wholesale & retail | 2022 |
| Hughes Property Management Limited | Hospitality | 2023 |
| Hughes Taxis Ltd | Transport & logistics | 2018 |
| Human Design World Ltd | Extraterritorial | 2024 |
| Humanheal Ltd | Administrative & support | 2024 |
| Humbergrange Limited | Construction | 1992 |
| Huttwil Ltd | Wholesale & retail | 2022 |
| Hylton Homes Limited | Real estate | 2011 |
| I-Rise Beyond Ltd | Administrative & support | 2025 |
| Ibfwrf Ltd | Administrative & support | 2024 |
| Ibwrf Ltd | Administrative & support | 2024 |
| Ice Shots Ltd | Information & communication | 2025 |
| Ihatrade Limited | Wholesale & retail | 2025 |
| Ihfa International Ltd | Administrative & support | 2025 |
| Ihsgb Limited | Other services | 2000 |
| IK Wonderworld Ltd | Extraterritorial | 2024 |
| Ikon 2022 Ltd | Extraterritorial | 2024 |
| Ilko Limited | Professional & scientific | 2008 |
| Illtyd Services CYF | Information & communication | 2015 |
| Illtyd Ventures Limited | Financial services | 2017 |
| Imagerights Ltd | Administrative & support | 2024 |
| Immosense Ltd | Extraterritorial | 2025 |
| Imotion Life Ltd | Administrative & support | 2022 |
| IN2CRAFT Ltd | Wholesale & retail | 2020 |
| Increase Traffic Ltd | Professional & scientific | 2019 |
| Indigo West (London) Limited | Hospitality | 2004 |
| Inky Blue Ltd | Manufacturing | 2025 |
| Inn Caterers Limited | Hospitality | 1997 |
| Innerheal Spirit Ltd | Administrative & support | 2023 |
| Innohave Ltd | Other services | 2023 |
| Innovatis Developments Limited | Real estate | 2016 |
| Innovatis Investments Ltd | Professional & scientific | 2016 |
| Inred Ltd | Other services | 2022 |
| Inside DNB Music Ltd | Information & communication | 2025 |
| Inspection.Ai Ltd | Information & communication | 2023 |
| Inspirational Paths Ltd | Administrative & support | 2023 |
| Insulism Ltd | Other services | 2019 |
| International Connectivity Services Ltd | Construction | 2019 |
| International M&B Consultancy Ltd | Information & communication | 2025 |
| International Palace Group Ltd | Hospitality | 2024 |
| International Plant Commissioning Ltd | Manufacturing | 2012 |
| Into Heart Ltd | Administrative & support | 2022 |
| Inver Peche Limited | Administrative & support | 1990 |
| IPC Group Ltd | Administrative & support | 2021 |
| IR Easy PAY (Ireasypay) Limited | Wholesale & retail | 2020 |
| Irbit Ltd | Other services | 2022 |
| Irfon Davies Limited | Agriculture & fishing | 2002 |
| Iron Crest Consultancy Ltd | Professional & scientific | 2025 |
| Isaac Wealth Limited | Financial services | 2013 |
| Italian Grape Escapes Ltd | Administrative & support | 2018 |
| Ivojo Multimedia Limited | Wholesale & retail | 2000 |
| Iwde - International Ltd | Administrative & support | 2025 |
| Iyannar Properties Ltd | Real estate | 2024 |
| J & K Scale Properties LLP | | 2015 |
| J & S Evans Denture LAB Limited | Health & social care | 2016 |
| J B & SON Civil Engineering Limited | Construction | 2021 |
| J B & SON Holdings Ltd | Financial services | 2022 |
| J J C & H E George Limited | Agriculture & fishing | 2005 |
| J L Davies Pembs Ltd | Manufacturing | 2025 |
| J P T Engineering Ltd | Manufacturing | 2016 |
| J W P & Daughter Limited | Agriculture & fishing | 2009 |
| J&T Smart Solutions Ltd | Other services | 2017 |
| J.P.R.Supplies Ltd | Wholesale & retail | 2007 |
| J.R.F. James & Sons Limited | Agriculture & fishing | 2003 |
| Jalap Contracting Ltd | Other services | 2022 |
| Jamangie Trading Ltd. | Wholesale & retail | 2015 |
| James Brothers Enterprises Limited | Agriculture & fishing | 2004 |
| James Ratford Bridge Limited | Manufacturing | 2002 |
| Jana Limited | Information & communication | 1998 |
| Janlun Ltd | Wholesale & retail | 2024 |
| Jas-Bars Ltd | Real estate | 2004 |
| Jason Hirst Ltd | Information & communication | 2014 |
| JCP Properties Ltd | Real estate | 2024 |
| Jeff Bevan Plumbing & Heating Limited | Construction | 2010 |
| Jemimah Consulting Limited | Professional & scientific | 2011 |
| Jerome's Your Painter Limited | Construction | 2025 |
| Jhvt Holdings Ltd | Financial services | 2026 |
| Jhvt Property Ltd | Real estate | 2026 |
| JIA Systems Limited | Professional & scientific | 2011 |