| Horrigan Security & Risk Management Ltd | Administrative & support | 2025 |
| Horse & Jockey Gastro Limited | Extraterritorial | 2017 |
| Hosokawa Micron Limited | Manufacturing | 1964 |
| Hot Scents Limited | Manufacturing | 2019 |
| Hove Fintech Consulting Ltd | Information & communication | 2024 |
| Howarth Court Limited | Extraterritorial | 2014 |
| HP Walker Enterprise Ltd | Wholesale & retail | 2014 |
| HR Gems Training & Consultancy Ltd | Administrative & support | 2026 |
| Hsiep Limited | Professional & scientific | 2022 |
| HSK Lettings & Property Management Limited | Real estate | 2023 |
| HTC (FAR East) Limited | Wholesale & retail | 1993 |
| HTC Group Limited | Wholesale & retail | 1983 |
| HTC Health Limited | Wholesale & retail | 2011 |
| Hudson Hill Consulting Limited | Information & communication | 2004 |
| Hughes Hooves Limited | Agriculture & fishing | 2014 |
| Humuson UK Ltd | Agriculture & fishing | 2026 |
| Hurst Joinery Limited | Manufacturing | 2001 |
| Husco International One Ltd | Manufacturing | 2015 |
| Husco International Partners LLP | | 2015 |
| Husco International Two Ltd | Manufacturing | 2015 |
| HVE Solutions Limited | Construction | 2013 |
| Hydro-Proexterior.Com Ltd | Administrative & support | 2026 |
| Hyjetts NW Limited | Financial services | 2016 |
| I J & M Ltd | Professional & scientific | 2017 |
| I&F Access & Contracting Limited | Construction | 2026 |
| I.I.E.D Property Ltd | Real estate | 2024 |
| Ianna Ltd | Manufacturing | 2026 |
| Ice Group Holdings Ltd | Construction | 2022 |
| Iceskimo Merchandise Ltd | Wholesale & retail | 2022 |
| ICW Capital Limited | Real estate | 2013 |
| ICW Offices Limited | Real estate | 2023 |
| ICW Property Limited | Real estate | 2017 |
| ID Management Services Limited | Hospitality | 2017 |
| Ideal (Knowsley) Limited | Wholesale & retail | 1986 |
| Iesha Creative & Co Ltd | Professional & scientific | 2025 |
| IG Consultancy Services Ltd | Information & communication | 2014 |
| Igsm Ltd | Wholesale & retail | 2014 |
| IH Safety Ltd | Construction | 2002 |
| IHS Denman Limited | Health & social care | 2023 |
| Ilukasolutions Ltd | Wholesale & retail | 2025 |
| IM Michaela Ltd | Health & social care | 2024 |
| Image PDC Ltd | Extraterritorial | 2004 |
| Immersive Tech Solutions Ltd | Information & communication | 2024 |
| Impact TM Ltd | Construction | 2025 |
| Impress Visuals Limited | Professional & scientific | 2006 |
| Impression Health & Support Apartments Limited | Health & social care | 2018 |
| Impression Health & Support Chester Operations Ltd | Health & social care | 2021 |
| Impression Health & Support Derby House Property Ltd | Health & social care | 2023 |
| Impression Health & Support Domiciliary Care Agency Ltd | Health & social care | 2018 |
| Impression Health and Support Chester Ltd | Health & social care | 2019 |
| Impression Health and Support Construction Ltd | Extraterritorial | 2017 |
| Impression Health and Support Derby House Limited | Health & social care | 2026 |
| Impression Health and Support Liverpool Ltd | Health & social care | 2017 |
| Impression Health and Support UK Ltd | Health & social care | 2017 |
| Impression Holdings Limited | Financial services | 2023 |
| Incite Digital Limited | Information & communication | 2021 |
| Independent Living PA Ltd | Health & social care | 2024 |
| Indigo Eco Solutions Ltd | Construction | 2023 |
| Indigo Plumbing, Heating & Renewables Ltd | Construction | 2014 |
| Industrial Cooling Equipment Limited | Construction | 1992 |
| Industrial Performance Systems Ltd | Construction | 2019 |
| Ineos Chlor Trustees Limited | Financial services | 2001 |
| Ineos Enterprises Group Limited | Manufacturing | 2003 |
| Ineos Inovyn Limited | Professional & scientific | 2013 |
| Ineos Newton Aycliffe Trustees Limited | Manufacturing | 1983 |
| Ineos Runcorn (TPS) Holdings Limited | Energy | 2008 |
| Ineos Runcorn (TPS) Limited | Energy | 2008 |
| Ineos Technologies (Holdings) Limited | Professional & scientific | 2008 |
| Ineos Technologies (Vinyls) Limited | Manufacturing | 2009 |
| Ineos Vinyls Holdings Limited | Professional & scientific | 2001 |
| Ineos Vinyls Limited | Manufacturing | 2005 |
| Infinity Beauty & Holistic Ltd | Wholesale & retail | 2025 |
| Infusion Hair Design Limited | Extraterritorial | 2017 |
| Innotech Engineering Services Ltd | Professional & scientific | 2024 |
| Innovative Food Supplements Ltd | Financial services | 2025 |
| Innovolt Electrical Contractors Ltd | Construction | 2025 |
| Inovyn Chlorvinyls Holdings Limited | Professional & scientific | 2009 |
| Inovyn Chlorvinyls Limited | Manufacturing | 2000 |
| Inovyn Energy Limited | Energy | 1986 |
| Inovyn Enterprises Limited | Manufacturing | 2003 |
| Inovyn Europe Limited | Manufacturing | 2016 |
| Inovyn Finance Limited | Professional & scientific | 2009 |
| Inovyn Group Treasury Limited | Professional & scientific | 2007 |
| Inovyn Newco 2 Limited | Professional & scientific | 2003 |
| Inovyn Newton Aycliffe Limited | Manufacturing | 1982 |
| Inovyn Services Limited | Manufacturing | 2003 |
| Inspec Elec Limited | Professional & scientific | 2014 |
| Inspectors Limited | Manufacturing | 2017 |
| Instant Cars NW Ltd | Wholesale & retail | 2025 |
| Integrated Chemicals Specialties UK Limited | Professional & scientific | 1992 |
| Integrated Health and Safety Limited | Construction | 2002 |
| Integrated Network Services Limited | Information & communication | 2010 |
| Intellect Engineering Ltd | Professional & scientific | 2024 |
| Intelligent Business Design Ltd | Information & communication | 2012 |
| Inter:Liner Ltd | Transport & logistics | 2019 |
| Interior Focus Ltd | Professional & scientific | 2025 |
| Interior Paint Refurbishment Limited | Manufacturing | 2016 |
| Interject Ltd | Information & communication | 2002 |
| International Ibooks Limited | Professional & scientific | 2016 |
| Invictis Group Limited | Construction | 2025 |