| Heyford Commercial Limited | Real estate | 2012 |
| Heyford Fitness Limited | Arts & recreation | 2025 |
| Heyford Hill Horticultural Ltd | Agriculture & fishing | 2020 |
| Heyford Installations Limited | Other services | 2021 |
| Heyford Park Developments Limited | Real estate | 2015 |
| Heyford Park Estate Limited | Real estate | 2012 |
| Heyford Park Holdings 2 Limited | Real estate | 2013 |
| Heyford Park Holdings Limited | Real estate | 2012 |
| Heyford Park Leisure Limited | Real estate | 2017 |
| Heyford Park Management Company Limited | Real estate | 1995 |
| Heyford Park VC Lease Limited | Real estate | 2020 |
| Heyford Residential Limited | Real estate | 2012 |
| Heyford Wharf Limited | Arts & recreation | 2001 |
| HGC Events Limited | Wholesale & retail | 2025 |
| HI Baldon Ltd | Hospitality | 2023 |
| Hibb Solutions Ltd | Professional & scientific | 2017 |
| Hidden Brook Limited | Households | 2018 |
| High Consultants UK Ltd | Professional & scientific | 2021 |
| High ELM Stud Ltd | Agriculture & fishing | 2025 |
| High Spec Composites Ltd | Manufacturing | 2010 |
| High Street & Hospitality Business Solutions Limited | Administrative & support | 2025 |
| High Street Smiles Ltd | Health & social care | 2013 |
| High Tiger Ltd | Professional & scientific | 2023 |
| Highbury Advisory Ltd | Professional & scientific | 2014 |
| Highbury Property Developments Limited | Real estate | 2024 |
| Highland Leisure Management Limited | Hospitality | 2019 |
| Hill Professional Services Ltd | Professional & scientific | 2023 |
| Hills of Surrey Limited | Extraterritorial | 2003 |
| Hillside View Property Investments Ltd | Real estate | 2026 |
| Hilsea Dental Care Limited | Health & social care | 2010 |
| Hindon Farms Limited | Agriculture & fishing | 2009 |
| Hinted Properties Ltd | Households | 2023 |
| Hispanidad Ltd | Real estate | 2024 |
| Hispeed Ltd | Manufacturing | 2021 |
| Historic & Classic Vehicles Alliance Limited | Other services | 2021 |
| Historit Limited | Transport & logistics | 2013 |
| Hive Mortgage Solutions Limited | Financial services | 2025 |
| Hive Project Solutions Ltd | Professional & scientific | 2026 |
| Hivings Hill Properties Limited | Construction | 2018 |
| HK Airtech Solutions Ltd | Manufacturing | 2024 |
| HKB Consult Limited | Professional & scientific | 2012 |
| HLA Consultants Ltd | Other services | 2015 |
| HMG Law Secretarial Limited | Professional & scientific | 2007 |
| HNP Landscape Solutions Ltd | Administrative & support | 2020 |
| Hobby Communications Limited | Professional & scientific | 1980 |
| Hoghton Street Dental Care Limited | Health & social care | 2011 |
| HOL Transport Ltd | Transport & logistics | 2013 |
| Holistic Axis Limited | Education | 2023 |
| Holistique Care and Wellness Ltd Ltd | Public administration | 2023 |
| Hollinton Homes Ltd | Real estate | 2023 |
| Holloway Kitchens & Bathrooms Ltd | Construction | 2025 |
| Homescape Property Renovations Ltd | Construction | 2024 |
| Honey Hive BEE Ltd | Real estate | 2026 |
| Honeybee Marketing Ltd | Wholesale & retail | 2023 |
| Honour Window & Door Solutions Limited | Construction | 2014 |
| Hooks Heating Ltd | Construction | 2022 |
| Hope RD. (Holdings) Limited | Financial services | 2024 |
| Hopkin Enterprises Limited | Real estate | 2020 |
| Horizon Tax Ltd | Professional & scientific | 2013 |
| Hosf Group Ltd | Financial services | 2025 |
| Hosf Properties Ltd | Real estate | 2026 |
| Hot TUB Studio Limited | Administrative & support | 2020 |
| Hot Tubs Oxfordshire Ltd | Other services | 2019 |
| Hotel Solution IT Limited | Information & communication | 2012 |
| Hotequip Ltd | Manufacturing | 2011 |
| Houlston UK Limited | Wholesale & retail | 2020 |
| House Made Ready Ltd | Professional & scientific | 2025 |
| Howard Stone Consulting Limited | Professional & scientific | 2014 |
| Howe Lettings Limited | Real estate | 2025 |
| Howson Fabrications Limited | Manufacturing | 2014 |
| Hoya Property Ltd | Real estate | 2021 |
| Hpgco Ltd | Real estate | 2023 |
| HSR Networks Limited | Professional & scientific | 2019 |
| Hub Publishing Ltd | Administrative & support | 1995 |
| Hudhud Associates Ltd | Professional & scientific | 2018 |
| Hudson & SON Builders Ltd | Construction | 2025 |
| Hudson Group London Limited | Hospitality | 2024 |
| Humanistics Limited | Professional & scientific | 1999 |
| Hungerhill Leisure Limited | Real estate | 2018 |
| Hunt 4 a Bargain Limited | Wholesale & retail | 2014 |
| Hurlingham Polo Equestrian Limited | Wholesale & retail | 2023 |
| Hussar Electrical Services Ltd | Construction | 2024 |
| Hutchinson & Hutchinson Ltd | Professional & scientific | 2024 |
| Huxamild Ltd | Real estate | 2017 |
| HVS Image Software Ltd | Information & communication | 2006 |
| HVW 3120 Ltd | Hospitality | 2024 |
| HWL Installations Ltd | Professional & scientific | 2024 |
| Hybrid Marine International Limited | Manufacturing | 2023 |
| Hykit Infrastructure Limited | Manufacturing | 2026 |
| Hykit Limited | Manufacturing | 2024 |
| Hynd Healthcare Limited | Professional & scientific | 2015 |
| Hynes Helicopter Maintenance Ltd | Transport & logistics | 2013 |
| Hyperion Consulting PVT Limited | Information & communication | 2024 |
| I AM Lisa Ward Ltd | Professional & scientific | 2023 |
| I AM2U Ltd | Professional & scientific | 2022 |
| I.S.E. Drives Limited | Administrative & support | 1996 |
| I.T.D. Limited | Education | 2002 |
| Iain Macrae Limited | Professional & scientific | 2017 |
| IAN Field Consulting Limited | Professional & scientific | 2014 |
| IAN Hunter Consultancy Ltd | Professional & scientific | 2024 |