| Hirestreet Limited | Information & communication | 2017 |
| HIT Road Limited | Transport & logistics | 2017 |
| HJM Property Investments Ltd | Real estate | 2024 |
| HK Pro Maintenance Ltd | Construction | 2025 |
| HKD Consulting Ltd | Professional & scientific | 2015 |
| Hoarestone Lock Management Company Limited | Households | 2018 |
| Hobhans Ltd | Real estate | 2020 |
| Hodson Baker Limited | Real estate | 2017 |
| HOF Rogers Financial Limited | Financial services | 2024 |
| Holczer Ltd | Other services | 2017 |
| Holdall & Co Ltd | Administrative & support | 2012 |
| Holland Land and Property Limited | Real estate | 2013 |
| Holly Collinson Health Limited | Professional & scientific | 2026 |
| Home-Start Corby Limited | Other services | 2005 |
| Homecrafted Foods Ltd | Manufacturing | 2026 |
| Hondo Investments Ltd | Transport & logistics | 2025 |
| Honeb Limited | Health & social care | 2013 |
| Honey Bunny Ltd | Manufacturing | 2021 |
| Hope Residential Ltd | Real estate | 2019 |
| Hospitallers of Saint Thomas of Canterbury Ltd | Education | 2024 |
| Hot Marketing Limited | Professional & scientific | 2003 |
| House at Number One Ltd | Wholesale & retail | 2023 |
| House of Ezekiel Ltd. | Wholesale & retail | 2016 |
| House of Nico Investments Limited | Health & social care | 2025 |
| Houseofkt Ltd | Wholesale & retail | 2021 |
| Howe Crescent Management Co Ltd. | Real estate | 1995 |
| Howielects Ltd | Professional & scientific | 2025 |
| HPS AR Holdings Ltd | Financial services | 2025 |
| HPS Property Ltd | Financial services | 2026 |
| HR Furniture Solutions Ltd | Other services | 2019 |
| HR Homes Limited | Real estate | 2012 |
| HS Shopfront and Shutters Ltd | Manufacturing | 2019 |
| HSH Architecture Ltd | Professional & scientific | 2015 |
| Hsirbu Ltd | Transport & logistics | 2022 |
| Hsskb Properties Limited | Real estate | 2021 |
| HT Creative Limited | Information & communication | 2022 |
| HTC Drylining Ltd | Construction | 2019 |
| Hubble and Freeman Limited | Wholesale & retail | 1956 |
| Human Partners Capital Limited | Administrative & support | 2025 |
| Hungarian Home Renovators Ltd | Construction | 2025 |
| Hunterprint Group PLC | Professional & scientific | 1965 |
| Hybrid Driving School Ltd | Education | 2022 |
| Hydro-Energy Limited | Energy | 2011 |
| Hydrodan (Corby) Limited | | 1981 |
| Hygenloop Ltd | Information & communication | 2026 |
| Hyper Motorsport Ltd | Arts & recreation | 2023 |
| Hyuntosh Ltd | Construction | 2024 |
| I & J Northover Limited | Other services | 2002 |
| I DO Memories Ltd | Information & communication | 2024 |
| I Foam Limited | Manufacturing | 2008 |
| I Ford Ltd | Health & social care | 2025 |
| I Y Commercial Limited | Real estate | 2021 |
| I&M&Sons Carpentry & Joinery Ltd | Construction | 2017 |
| Iacob&Karina Ltd | Manufacturing | 2026 |
| IAN Taylor Consulting Limited | Professional & scientific | 2014 |
| Iancu Go Logistics Ltd | Transport & logistics | 2026 |
| Iasis Therapies Limited | Extraterritorial | 2011 |
| IB Health Limited | Health & social care | 2023 |
| IBA Dynamics International Limited | Education | 2018 |
| Ibiza Recruit Ltd | Other services | 2016 |
| Ibmaga Records Ltd | Information & communication | 2019 |
| Ibrahim Worldwide Limited | Wholesale & retail | 2025 |
| IC Smart Repairs Limited | Wholesale & retail | 2022 |
| Icnt Limited | Water & waste | 2011 |
| Icon Safety Systems Limited | Administrative & support | 2025 |
| ICP Services Limited | Professional & scientific | 2019 |
| ID Building & Construction Ltd | Construction | 2015 |
| ID Props Ltd | Real estate | 2021 |
| IFF Software Solutions Ltd | Information & communication | 2017 |
| Ifizio Ltd | Wholesale & retail | 2021 |
| IFR Automotive Ltd | Wholesale & retail | 2025 |
| IGA Transport Limited | Transport & logistics | 2017 |
| Ignite Competitions Ltd | Information & communication | 2023 |
| Ikalott Ltd | Health & social care | 2019 |
| Ikes Care Service Limited | Health & social care | 2023 |
| Iles & Shatford Holdings Ltd | Financial services | 2024 |
| Iles Media Group Ltd | Professional & scientific | 2021 |
| Ilietrans Ltd | Transport & logistics | 2014 |
| Ilke Ltd | Wholesale & retail | 2020 |
| Illumino Lighting Ltd | Wholesale & retail | 2019 |
| Ilys Limited | Wholesale & retail | 2016 |
| IM Quality Solutions Ltd | Professional & scientific | 2016 |
| Imagex IT Limited | Information & communication | 2014 |
| Imagex Medical Ltd | Administrative & support | 2009 |
| Immigration Law Group Ltd | Professional & scientific | 2021 |
| Immigration Law ROI Ltd | Education | 2003 |
| Impact Healthcare Consultancy Limited | Health & social care | 2023 |
| Impact PDR Ltd | Wholesale & retail | 2019 |
| Imperia Marketing Ltd | Professional & scientific | 2019 |
| Imperial Ventures Limited | Financial services | 2025 |
| Implantdent Ltd | Health & social care | 2020 |
| IN the Dark Entertainment & Promotions Limited | Administrative & support | 2024 |
| In.Rehoboth Ltd | Health & social care | 2025 |
| IN2CONNECT UK Ltd | Wholesale & retail | 2002 |
| Inaq Ltd | Wholesale & retail | 2020 |
| Independent Advice for Business Limited | Professional & scientific | 2011 |
| Independent Project Development Services Limited | Information & communication | 2007 |
| Industrial & Commercial Coatings Limited | Administrative & support | 2010 |
| Industrial Engineering Solutions Ltd | Manufacturing | 2023 |
| Infinity Images Ltd | Construction | 2024 |