| Historic Conservation Limited | Professional & scientific | 2022 |
| HJS Personnel Limited | Other services | 2008 |
| HK Smart Solutions Limited | Information & communication | 2025 |
| HL Invest Ltd | Manufacturing | 2014 |
| Hmbp Holdings Limited | Financial services | 2013 |
| Hnvg Ltd | Professional & scientific | 2022 |
| Hobs Moat Investments Limited | Construction | 1962 |
| Hodges-Tradingcards Ltd | Wholesale & retail | 2021 |
| Hodson Business Solutions Limited | Professional & scientific | 2008 |
| Hogan Agencies Limited | Wholesale & retail | 2022 |
| Hoggl Limited | Information & communication | 2022 |
| Holland Chiropractic Ltd | Professional & scientific | 2024 |
| Hollow FOX Ltd | Manufacturing | 2023 |
| Holmer Green Service Centre Limited | Wholesale & retail | 2024 |
| Holtz Trading Limited | Real estate | 2016 |
| Holy Reformer Ltd | Administrative & support | 2026 |
| Holyford Ltd | Education | 2025 |
| Home Assured Surveys Ltd | Other services | 2025 |
| Home Farm Speciality Foods Limited | Wholesale & retail | 2010 |
| Home Flow Utilities Ltd | Construction | 2023 |
| Home Pools Limited | Construction | 2000 |
| Home Spa 1994 Ltd | Other services | 2025 |
| Home-Start Banbury & Chipping Norton | Health & social care | 2005 |
| Homesafe Banbury Limited | Construction | 2021 |
| Honest Perspectives Ltd | Wholesale & retail | 2022 |
| Honey BEE Suppliers Limited | Agriculture & fishing | 2003 |
| Honey Eden Ltd | Wholesale & retail | 2020 |
| Honeysalt Ltd | Hospitality | 2025 |
| Honiton Ventures Limited | Hospitality | 2024 |
| Hook Norton Brewery Company,Limited(The) | Manufacturing | 1900 |
| Hook Norton Construction Ltd | Construction | 2019 |
| Hook Norton Veterinary Group LLP | | 2010 |
| Hookedto Limited | Wholesale & retail | 2011 |
| Hopark Ltd | Real estate | 2021 |
| Hope Ahead Social Care Ltd | Health & social care | 2023 |
| Hope's Micro Farming Ltd | Agriculture & fishing | 2023 |
| Hopefield Enterprises Limited | Administrative & support | 2012 |
| Hopwell Investments Ltd | Professional & scientific | 2019 |
| Horgan Lands Limited | Agriculture & fishing | 2018 |
| Horizon Technical Ltd | Energy | 2018 |
| Horn Hill Estates Limited | Real estate | 2006 |
| Hornton Financial Services Limited | Professional & scientific | 2020 |
| Horse and Jockey Bodicote Ltd | Hospitality | 2015 |
| Horseworld Limited | Arts & recreation | 2005 |
| Horton Designs Limited | Construction | 2004 |
| Host Hobbit Ltd | Professional & scientific | 2024 |
| Hot Source Games Ltd | Information & communication | 2009 |
| House of Cool Ltd | Wholesale & retail | 2001 |
| House of Hammond Ltd | Professional & scientific | 2025 |
| Hover Health Ltd | Health & social care | 2018 |
| Hoverblox Ltd | Manufacturing | 2025 |
| Howard Green Projects Limited | Professional & scientific | 2009 |
| Howard Properties Limited | Agriculture & fishing | 1987 |
| Howes Lane Projects LLP | | 2012 |
| HP Tutors Ltd | Education | 2025 |
| Hpcs Holdings Ltd | Financial services | 2024 |
| HR Compliance Hub Limited | Administrative & support | 2024 |
| HSJ Limited | Construction | 2017 |
| HSS708 Ltd | Wholesale & retail | 2026 |
| HT Communications Ltd | Professional & scientific | 2019 |
| HT Land and Homes Ltd | Real estate | 2022 |
| HTLOGISTICS786 Ltd | Transport & logistics | 2025 |
| Hualix Developments Ltd | Construction | 2011 |
| Hudson Portfolio Limited | Professional & scientific | 2022 |
| Humanity in Motion Limited | Administrative & support | 2014 |
| Hume Health Ltd | Health & social care | 2022 |
| Hummingbird Leadership Limited | Education | 2025 |
| Humphris (Banbury) Limited | Real estate | 1961 |
| Hundred Percent Aviation Limited | Transport & logistics | 2000 |
| Hundred Percent Holdings Limited | Financial services | 2017 |
| Hundred Percent Management Limited | Professional & scientific | 2003 |
| Hungerford Heath Limited | Extraterritorial | 2025 |
| Hungwe Ltd | Health & social care | 2021 |
| Hunters Moon Candles Ltd | Wholesale & retail | 2018 |
| Hunts of Cotswolds Property Care Ltd | Construction | 2026 |
| Hurdsfield Events Ltd | Hospitality | 2025 |
| Hutchings & Keasley (Properties) Limited | Real estate | 1931 |
| HVZ Medical Consultancy Limited | Health & social care | 2014 |
| Hylton Finance Limited | Financial services | 2021 |
| I Automotive Technologies Limited | Wholesale & retail | 2024 |
| I D G Surveying Limited | Professional & scientific | 2014 |
| I Plus a Ltd | Information & communication | 2014 |
| I-D8 Limited | Information & communication | 2005 |
| I-Go Optical Limited | Wholesale & retail | 2006 |
| I-Gtm Ltd | Transport & logistics | 2017 |
| I.J. Carpentry and Joinery Limited | Construction | 1997 |
| I4 Business Services Ltd | Professional & scientific | 2017 |
| I:Med (Europe) Ltd | Professional & scientific | 2010 |
| IAN O'Brien Studio Limited | Professional & scientific | 2014 |
| IAN Poulter Enterprises Limited | Wholesale & retail | 2006 |
| Ibee Utilities Ltd | Construction | 2022 |
| Ibrandiq Limited | Information & communication | 2012 |
| Ibvp Limited | Professional & scientific | 2024 |
| ICD Logistics Courier Limited | Transport & logistics | 2020 |
| Ichim Logistics Ltd | Transport & logistics | 2023 |
| Icona Clear Solutions Ltd | Professional & scientific | 2025 |
| Iconix Agility Shows Ltd | Other services | 2022 |
| Icpopescu Trans Ltd | Other services | 2024 |
| ICT SO Easy Ltd | Information & communication | 2020 |
| Idea Poole Ltd | Information & communication | 2024 |