| HE2023UK Limited | Hospitality | 2023 |
| Head 2 Head Limited | Professional & scientific | 1996 |
| Heading on Ltd | Administrative & support | 2016 |
| Headington and MCS BUS Partnership Limited | Transport & logistics | 2022 |
| Headington Carriers Limited | Transport & logistics | 1999 |
| Headington Flooring Limited | Construction | 2023 |
| Headington Homewares Limited | Wholesale & retail | 2005 |
| Headington Limited | Hospitality | 2025 |
| Headington Medical Consultancy Ltd | Education | 2020 |
| Headington Medical Technology Ltd | Manufacturing | 2019 |
| Headington Psychology Service Ltd | Professional & scientific | 2015 |
| Headington School Oxford Limited | Education | 1915 |
| Headington School Services Limited | Education | 1992 |
| Headington Sushi Ltd | Manufacturing | 2022 |
| Headington Town Limited | Real estate | 2017 |
| Headlong Commercial Limited | Arts & recreation | 2014 |
| Headlong Theatre Limited | Arts & recreation | 1974 |
| Headmoor Limited | Other services | 1999 |
| Headroom Data Consultancy Limited | Information & communication | 2025 |
| Heads in the Clouds Ltd | Manufacturing | 2024 |
| Headway Technologies Ltd | Information & communication | 2010 |
| Healey Lighting Limited | Information & communication | 2024 |
| Health Economics Innovation Ltd | Professional & scientific | 2024 |
| Health Education for Women of Africa | Professional & scientific | 2025 |
| Health First Medical Staffing Ltd | Health & social care | 2014 |
| Health for Life Clinics Ltd. | Information & communication | 2021 |
| Health Holdings Ltd | Professional & scientific | 2022 |
| Health Squared Ltd. | Arts & recreation | 2017 |
| Health&Welbeing Ltd | Health & social care | 2025 |
| Healthcare Artificial Intelligence Solutions Limited | Public administration | 2026 |
| Healthcare Dynamics Ltd | Professional & scientific | 2020 |
| Healthcare Innovation Network CIC | Professional & scientific | 2024 |
| Healthcare Priority Solutions Ltd | Professional & scientific | 2022 |
| Healthier Oxford City PCN Limited | Health & social care | 2023 |
| Healthwatch Limited | Health & social care | 2009 |
| Healthy Creative Foods Ltd | Other services | 2019 |
| Healthy Fied Ltd | Wholesale & retail | 2025 |
| Healthy Goodies Limited | Hospitality | 2024 |
| Heaps Hall Limited | Administrative & support | 2021 |
| Heartland Home Renovations Ltd | Real estate | 2025 |
| Heartland Homes Ltd | Real estate | 2020 |
| Heat Afro Lounge Ltd | Hospitality | 2025 |
| Heat Help Limited | Professional & scientific | 2005 |
| Heatmax Insulations Limited | Wholesale & retail | 1970 |
| Heaton Design and Engineering Ltd | Professional & scientific | 2015 |
| Heaton Quality Homes Limited | Real estate | 2019 |
| Heatondale Ltd | Real estate | 2020 |
| Heatroot Ltd | Manufacturing | 2021 |
| Heatvalley UK Limited | Wholesale & retail | 2021 |
| Heaven & Hell Tattoo Ltd | Arts & recreation | 2016 |
| Heavens Touch Holistic Massage Limited | Health & social care | 2022 |
| Heavnely Dealz Limited | Wholesale & retail | 2023 |
| Hebii Kids Limited | Professional & scientific | 2013 |
| Hedena Health Limited | Health & social care | 2017 |
| Hedges Butchers Limited | Other services | 2017 |
| Hedron Limited | Construction | 2013 |
| Hedwig Health Limited | Information & communication | 2023 |
| Heidi's Pilates and Yoga Ltd | Other services | 2026 |
| Hejira Ltd | Arts & recreation | 2026 |
| Hekima Bridge CIC | Health & social care | 2025 |
| Helen & Douglas House | Health & social care | 2000 |
| Helen & Douglas House (Trading) Limited | Wholesale & retail | 2004 |
| Helen Fletcher Consulting Ltd | Professional & scientific | 2025 |
| Helen Fowler & Associates Limited | Professional & scientific | 2008 |
| Heli Services Limited | Administrative & support | 2016 |
| Helicon Quantum Systems Ltd | Manufacturing | 2026 |
| Helio Consulting Ltd | Information & communication | 2022 |
| Helio Display Materials Limited | Professional & scientific | 2016 |
| Helix Films Limited | Information & communication | 2013 |
| Helix House Natural Health Limited | Health & social care | 2019 |
| Hellesdon Scotland Limited | Real estate | 2000 |
| Hellfire Trading Limited | Wholesale & retail | 2011 |
| Hellios Holdings Limited | Financial services | 2014 |
| Hellios Information Limited | Administrative & support | 2012 |
| Hello CAS Ltd | Wholesale & retail | 2017 |
| Help for Children in Uganda | Education | 2005 |
| Help ME DO My Homework Ltd | Extraterritorial | 2022 |
| Helpd Ltd | Administrative & support | 2017 |
| Helsby & Co. Investments Limited | Real estate | 2023 |
| Helweg-Larsen Consulting Ltd | Professional & scientific | 2025 |
| Hendred House Management Limited | Hospitality | 1990 |
| Hendred Investments Ltd | Real estate | 2016 |
| Henley Past Practice Limited | Extraterritorial | 2012 |
| Henlow Racing Limited | Information & communication | 1997 |
| Henry Cornelius Productions Limited | Extraterritorial | 1956 |
| Henry Lowe Recruitment Partners Limited | Administrative & support | 2014 |
| Henry Taxi Limited | Administrative & support | 2016 |
| Henry TC Ltd | Wholesale & retail | 2025 |
| Henry Venners Limited | Professional & scientific | 2016 |
| Henrypricilla Ltd | Wholesale & retail | 2022 |
| Hensai Ltd. | Information & communication | 2024 |
| Hentom Pubs Limited | Hospitality | 2011 |
| HER Build Ltd | Construction | 2025 |
| HER Cars Ltd | Transport & logistics | 2024 |
| HER Equality Rights and Autonomy | Health & social care | 2005 |
| HER Ride Limited | Transport & logistics | 2016 |
| Hera Salon Ltd | Other services | 2021 |
| Herald Graphics Limited | Manufacturing | 1986 |
| Herculi Ltd | Professional & scientific | 2022 |
| Heritage & F a Developments Ltd | Construction | 2025 |