| Hunters Hereditaments Limited | Real estate | 1983 |
| Huntington Homes Limited | Professional & scientific | 2002 |
| Huntington Mews (NO.2) Residents Association Limited | Households | 2001 |
| Huntington Ross Financial Services Limited | Financial services | 2012 |
| Huntington Ross Limited | Financial services | 2014 |
| Huntsman's Court Management Company Limited | Real estate | 2013 |
| Hurdle Court (Andover) Management Company Limited | Households | 2020 |
| Hurrikanetuning Ltd | Wholesale & retail | 2024 |
| Husky Photographic Ltd | Professional & scientific | 2022 |
| Huso Barbers Limited | Other services | 2023 |
| Huthart North Ltd | Other services | 2010 |
| Hutsman Ltd | Manufacturing | 2021 |
| Hutton North LLP | | 2024 |
| Hutton Peach Limited | Administrative & support | 2006 |
| Hutton Wandesley Estate LLP | | 2014 |
| Hutton Wandesley Farms Company Limited | Agriculture & fishing | 1967 |
| Hutton Wandsley Developments Limited | Real estate | 2014 |
| Huttons Ambo Farms Limited | Agriculture & fishing | 1970 |
| Huzzard Blocks Ltd | Manufacturing | 2021 |
| HW Peony Limited | Extraterritorial | 2021 |
| HWE Properties Limited | Real estate | 2024 |
| Hybris Property Ltd | Real estate | 2022 |
| Hyde Family JAM Ltd | Arts & recreation | 2023 |
| Hyde Family JAM Merchandise & Tickets Ltd | Arts & recreation | 2024 |
| Hyde Mawson Property Management Limited | Real estate | 2021 |
| Hyde Park Lets Limited | Real estate | 2020 |
| Hydegate Limited | Real estate | 1985 |
| Hydes of Boroughbridge Limited | Wholesale & retail | 2006 |
| Hydra Power (York) Limited | Wholesale & retail | 2011 |
| Hydro (ST Neots) Number One Management Company Limited | Households | 2005 |
| Hydrologiq Ltd | Information & communication | 2020 |
| Hydroseek Ltd | Professional & scientific | 2026 |
| Hyen Ltd | Manufacturing | 2024 |
| Hyggelig Properties Ltd | Hospitality | 2023 |
| Hylozoic Architects Ltd | Professional & scientific | 2018 |
| Hyper Sciences Agri-Tech Ltd | Professional & scientific | 2025 |
| Hyper Sciences Ltd | Manufacturing | 2017 |
| Hypotyposis Limited | Information & communication | 2025 |
| Hyrit Limited | Administrative & support | 2020 |
| Hzkaero Consultancy Ltd | Professional & scientific | 2024 |
| HØM Build Limited | Construction | 2025 |
| I AM UK Group Ltd | Health & social care | 2021 |
| I Buy ANY Bike Ltd | Wholesale & retail | 2021 |
| I CAN Play Tennis Ltd. | Arts & recreation | 2010 |
| I Fagiolini Projects Ltd | Arts & recreation | 2012 |
| I G Property Services Limited | Real estate | 2007 |
| I Garland Tiling Ltd | Construction | 2019 |
| I H Jointing Limited | Construction | 2018 |
| I Love YOU This Much Ltd | Arts & recreation | 2024 |
| I Love Zero Ltd | Wholesale & retail | 2020 |
| I M Phillips Ltd | Other services | 2006 |
| I Morrell Ltd | Construction | 2016 |
| I Pickard Associates Limited | Other services | 2019 |
| I Sleep at the Drake Ltd | Hospitality | 2020 |
| I-Finity Associates Limited | Information & communication | 2002 |
| I. Walsh Limited | Administrative & support | 2008 |
| I.C.T Waste Management Consultancy Ltd | Water & waste | 2020 |
| I.F. Supplements Ltd | Wholesale & retail | 2020 |
| I.M. (Networks) Limited | Professional & scientific | 1986 |
| I.R.O Consulting Limited | Professional & scientific | 2013 |
| I2I Developments Ltd | Education | 2009 |
| I2I Life Foundation | Education | 2011 |
| I2I Medical Ltd | Education | 2013 |
| I2I Sports Ltd | Education | 2013 |
| I4CU Limited | Information & communication | 2016 |
| Iain Hewitt Industries Limited | Arts & recreation | 2023 |
| Iain Scott Fabrications Limited | Manufacturing | 1995 |
| Iamnat Limited | Wholesale & retail | 2015 |
| IAN Calpin Landscape Services Limited | Administrative & support | 2005 |
| IAN Gostellow Ltd | Professional & scientific | 2019 |
| IAN Graham Technical Services Limited | Information & communication | 1995 |
| IAN H. Patterson & SON Limited | Transport & logistics | 2003 |
| IAN Hills Electronics Limited | Administrative & support | 2010 |
| IAN Mosey (Farming) Limited | Financial services | 2026 |
| IAN Mosey (Feed) Limited | Manufacturing | 2009 |
| IAN Mosey (Livestock) Limited | Agriculture & fishing | 2009 |
| IAN Mosey Group Limited | Financial services | 2026 |
| IAN Mosey Limited | Agriculture & fishing | 1979 |
| IAN Paragreen Ltd | Professional & scientific | 2025 |
| IAN Preston Consulting Ltd | Professional & scientific | 2024 |
| IAN Routledge Consultancy Limited | Other services | 2017 |
| IAN Smith Building Surveying & Conservation Limited | Professional & scientific | 2022 |
| IAN Wainwright Dipwcf Ltd | Other services | 2003 |
| IAN Willis Limited | Administrative & support | 2003 |
| IAN Winstone Electrical Ltd | Manufacturing | 2018 |
| Ianhughestv Ltd | Information & communication | 2012 |
| Iatrike Medical Writing and Consultancy Limited | Professional & scientific | 2017 |
| Ibanflex UK Ltd | Information & communication | 2020 |
| Ibbotson Industries Limited | Hospitality | 1999 |
| Ibbotsons Limited | Agriculture & fishing | 2017 |
| IBC (York) Limited | Transport & logistics | 2010 |
| IBE Property Limited | Real estate | 2018 |
| Ibidonstorage Ltd | Wholesale & retail | 2020 |
| IBP Media Ltd | Information & communication | 2018 |
| IBP Ventures Ltd | Professional & scientific | 2023 |
| Ibrick Technology Ltd | Professional & scientific | 2017 |
| ICC York Ltd | Administrative & support | 2023 |
| Ice Cubed Capital Limited | Construction | 2015 |
| Ice Cubed Group Ltd | Financial services | 2024 |
| Ice Cubed Land Ltd | Real estate | 2024 |