| Horsell Common Preservation Society | Other services | 2007 |
| Horsell Consultants Limited | Information & communication | 2008 |
| Horsell Ltd | Hospitality | 2023 |
| Horsell Nails & Spa Ltd | Other services | 2021 |
| Horsell Properties Ltd | Real estate | 2013 |
| Horsell Residents Association Ltd | Administrative & support | 2005 |
| Horsell Rise Close Residents Association Ltd | Households | 2020 |
| Horsell Tennis Club | Arts & recreation | 2019 |
| Hot Rock Butchery Limited | Wholesale & retail | 2013 |
| Hotdeals Ltd | Wholesale & retail | 2018 |
| House Cats Limited | Other services | 2016 |
| House of Jessie Limited | Other services | 2026 |
| House of Shah Ltd | Wholesale & retail | 2018 |
| House of Three London Limited | Extraterritorial | 2015 |
| Houstruction Ltd | Real estate | 2025 |
| HOW WE Coach Ltd | Information & communication | 2021 |
| Howard Dixon Limited | Real estate | 1993 |
| Howard Motor Company Limited | Wholesale & retail | 2003 |
| Howard Roofing Limited | Construction | 2022 |
| Howtel Limited | Real estate | 1995 |
| Howtorobot Limited | Information & communication | 2021 |
| HR Indeed Limited | Administrative & support | 2024 |
| HS Contracting Services Limited | Administrative & support | 2011 |
| HS Living Group Ltd | Real estate | 2025 |
| HSH Group Ltd | Real estate | 2017 |
| HSM Landscapes Ltd | Administrative & support | 2013 |
| HT Stroud Carpentry Ltd | Construction | 2015 |
| HTK Martial Arts Ltd | Arts & recreation | 2025 |
| Hubba Hubba Productions Limited | Information & communication | 2011 |
| Hubr Ltd | Professional & scientific | 2005 |
| Huckleberry Design Limited | Manufacturing | 2020 |
| Hudson Kendrick Ltd | Wholesale & retail | 2025 |
| HUE Lala Ltd | Manufacturing | 2025 |
| Hugh F D Jackson Limited | Other services | 2015 |
| Hugh Marr Ltd | Arts & recreation | 2017 |
| Hughzy's Sandwich Bar Ltd | Wholesale & retail | 2025 |
| Hugo Group Limited | Wholesale & retail | 2023 |
| Hulk’S Halal Food Ltd | Wholesale & retail | 2025 |
| Huma Holdings Limited | Financial services | 2015 |
| Human Diverse Ltd | Health & social care | 2021 |
| Human Factors Everywhere Ltd | Professional & scientific | 2019 |
| Human Resources Sovereign Ltd | Administrative & support | 2013 |
| Humandynamics Limited | Information & communication | 2020 |
| Humanwritten Ltd | Information & communication | 2025 |
| Humber Graving Dock and Engineering Company,Limited(The) | | 1909 |
| Humble Pavilion Limited | Financial services | 2026 |
| Hummingbird Works Ltd | Manufacturing | 2024 |
| Hungarian School London | Education | 2016 |
| Hunger's Spot Limited | Hospitality | 2026 |
| Huntadvertising Ltd | Professional & scientific | 2025 |
| Hunter RAY Property Ltd | Hospitality | 2024 |
| Hunter Strategic Solutions Limited | Administrative & support | 2013 |
| Hunter Street Food Ltd | Hospitality | 2025 |
| HUR Heating Ltd | Construction | 2024 |
| Hussain Legal Limited | Professional & scientific | 2023 |
| Hussey Holdings Limited | Hospitality | 2018 |
| Hutch Post Production Ltd | Information & communication | 2016 |
| Hutchinson Consultancy Limited | Extraterritorial | 2005 |
| Hutchison Catering Limited | Hospitality | 2008 |
| Hutview Property Solutions Ltd | Real estate | 2018 |
| HY Performance Consulting Ltd | Professional & scientific | 2021 |
| Hyde & Seek Productions Ltd | Information & communication | 2016 |
| Hyderabad Deccan Association UK Ltd | Health & social care | 2024 |
| Hydramach Limited | Manufacturing | 2014 |
| Hydrogen Resources Ltd | Manufacturing | 2020 |
| Hydrogen Supplies Limited | Extraterritorial | 1993 |
| Hydrovax Environmental Ltd | Water & waste | 2026 |
| Hypercar Solutions Group Limited | Financial services | 2023 |
| Hyskollari Ltd | Hospitality | 2019 |
| I & D Auto Servicing Ltd | Wholesale & retail | 2016 |
| I & J Consultants Limited | Information & communication | 2008 |
| I Build and Design Ltd | Construction | 2013 |
| I Care (MR) Limited | Health & social care | 2018 |
| I Drive Surrey Ltd | Transport & logistics | 2022 |
| I R Express Services Ltd | Administrative & support | 2019 |
| I T Protocol Limited | Information & communication | 2017 |
| I&L Biosystems UK Ltd | Wholesale & retail | 2016 |
| I&M Rendering Ltd | Construction | 2018 |
| I-Ikigai Ltd | Wholesale & retail | 2018 |
| I-Protect Roofing Solutions Ltd | Construction | 2025 |
| IAM Portafolio Limited | Real estate | 2020 |
| IAN Katte & Co Limited | Professional & scientific | 2018 |
| IAN Repton Physio Consultancy Ltd | Health & social care | 2019 |
| Iaudit Global Limited | Information & communication | 2024 |
| Iberian Property Investments Limited | Real estate | 2000 |
| IBN Mousa CIC | Education | 2026 |
| Iboo Services Ltd | Information & communication | 2012 |
| Ibuilders UK Ltd | Construction | 2021 |
| Ic-Coach Ltd | Administrative & support | 2021 |
| Icarus Training Ltd | Education | 2012 |
| Ice Cream Van Hire Ltd | Wholesale & retail | 2024 |
| Ice Cream Van Hire Surrey Ltd | Wholesale & retail | 2025 |
| Ice Hairdressing Limited | Education | 2003 |
| Icefields Consulting Limited | Information & communication | 2007 |
| Iclose Ltd | Financial services | 2020 |
| Icogne Capital Limited | Financial services | 2022 |
| Iconis Learning & Development Limited | Professional & scientific | 2010 |
| Iconnectcar Ltd | Transport & logistics | 2020 |
| Icscompany Limited | Information & communication | 2016 |
| Icstps Alfa-Metal Ltd | Administrative & support | 2014 |