| Heyford Studios Ltd | Information & communication | 2019 |
| Heygate & Sons Limited | Manufacturing | 1962 |
| Heygate Animal Feeds Limited | Wholesale & retail | 1997 |
| Heygate Contracting Limited | Agriculture & fishing | 2012 |
| Heygate Engineering Company Limited(The) | Transport & logistics | 1951 |
| Heygate Farms Swaffham Limited | Agriculture & fishing | 1953 |
| Heygate Grain Limited | Wholesale & retail | 1980 |
| Heygate Leasing Ltd. | Financial services | 1995 |
| Heygates Country Feeds Limited | Manufacturing | 2012 |
| Heygates Limited | Manufacturing | 1958 |
| Heygates Lodging Limited | Hospitality | 2021 |
| HFD Properties Limited | Real estate | 2024 |
| Hffelix Limited | Construction | 2024 |
| HFK Cooling Limited | Manufacturing | 2022 |
| HG Evolution Ltd | Wholesale & retail | 2023 |
| HGL Logistics Ltd | Transport & logistics | 2025 |
| HGV and More Limited | Transport & logistics | 2020 |
| HGV Driving Plus Ltd | Administrative & support | 2023 |
| HH Architectural Technology Ltd | Professional & scientific | 2025 |
| HH Architecture Ltd | Professional & scientific | 2013 |
| HH Cleans Ltd | Administrative & support | 2023 |
| HH Collective Limited | Wholesale & retail | 2016 |
| HH Dynamic Property Development Ltd | Real estate | 2024 |
| HH Platinum Clean Ltd | Administrative & support | 2025 |
| HH Play Ltd | Education | 2026 |
| Hhfmco Ltd | Households | 2020 |
| HI UNI Ltd | Education | 2025 |
| Hi-Per Tech Ltd | Manufacturing | 2026 |
| Hi-Tec Welding and Fabrication Services Limited | Manufacturing | 1999 |
| Hi-Tech Engineering Ltd | Wholesale & retail | 2017 |
| Hi-Tech Performance Ltd | Wholesale & retail | 2010 |
| HI55 Ventures Limited | Information & communication | 2020 |
| Hiab Haulage Ltd | Transport & logistics | 2019 |
| Hiartech Limited | Information & communication | 2018 |
| Hibbs & Co. Consultancy Ltd | Information & communication | 2016 |
| Hickory Dickory's Limited | Arts & recreation | 2004 |
| Hickory House Children's Day Nursery Limited | Education | 2000 |
| Hidden Depths (Devon) Limited | Real estate | 2023 |
| Hidden Depths Consulting Limited | Professional & scientific | 2006 |
| Hideaway Wood Farm Ltd | Agriculture & fishing | 2020 |
| Hielite Technologies Limited | Information & communication | 2023 |
| Higgins Bricklayers Limited | Construction | 2020 |
| Higgins Merrigan LLP | | 2026 |
| High Acre Developments Limited | Construction | 2014 |
| High Park Garage Limited | Extraterritorial | 1988 |
| High Range Flavors Limited | Wholesale & retail | 2025 |
| High Range Flavours Limited | Wholesale & retail | 2024 |
| High Street Dental Practice Limited | Health & social care | 2008 |
| High Tech & Evolution Ltd | Wholesale & retail | 2025 |
| High Tech Performance Ltd | Wholesale & retail | 2019 |
| High Voltage Systems Ltd. | Manufacturing | 1996 |
| Higham Builders Limited | Construction | 2014 |
| Higham Business Finance Ltd | Financial services | 2020 |
| Higham Horology Company Limited | Other services | 2023 |
| Highbourne (IS) Limited | Extraterritorial | 2025 |
| Highcliffe Care Centre Limited | Health & social care | 2006 |
| Higher Jump Limited | Transport & logistics | 2018 |
| Higher Jump Logistics Ltd | Transport & logistics | 2022 |
| Highfield Dental Practice Limited | Health & social care | 2007 |
| Highfield Homes (Northamptonshire) Ltd | Real estate | 2025 |
| Highfields Property Services Limited | Construction | 2018 |
| Highflyer Management Co. Ltd | Real estate | 2018 |
| Highgate House Conference Centre | | 1992 |
| Highland Roofing Ltd | Construction | 2025 |
| Highlander Property Services Limited | Construction | 2007 |
| Highmead House Limited | Health & social care | 2025 |
| Highspire Limited | Information & communication | 2007 |
| Hightec Properties Limited | Real estate | 2011 |
| Hightec Roofline Limited | Construction | 2007 |
| Highvaluepropertysolutions Ltd | Financial services | 2025 |
| Highweald Beverages Limited | Wholesale & retail | 2019 |
| Hihak Limited | Information & communication | 2025 |
| Hijinix Healthcare PVT Ltd | Health & social care | 2012 |
| Hilary AF Dolby Limited | Professional & scientific | 2013 |
| Hilary Knight Management Limited | Administrative & support | 2005 |
| Hillal Power Foods Limited | Hospitality | 2023 |
| Hillcrest Groundworks Ltd | Extraterritorial | 2022 |
| Hillcrest Recovery Ltd | Manufacturing | 2006 |
| Hilldown Properties Limited | Real estate | 2002 |
| Hillmorton Boat Services Limited | Arts & recreation | 2022 |
| Hillmorton Boats Limited | Arts & recreation | 2022 |
| Hills Harvest UK Ltd | Hospitality | 2019 |
| Hillton Limited | Construction | 2000 |
| Hilltop Real Estate Ltd | Real estate | 2024 |
| Hilltops (Daventry) Management Company Limited | Households | 2003 |
| Hillview Residential Home | | 1986 |
| Hillwood Properties Limited | Real estate | 2020 |
| Hillwood Property Developments Limited | Construction | 2025 |
| Hillyfields Limited | Education | 1994 |
| Himley Environmental Limited | Water & waste | 2012 |
| Hind Wellingborough Limited | Hospitality | 2017 |
| Hipodent Ltd | Health & social care | 2012 |
| Hira Group Ltd | Real estate | 2020 |
| Hira Property Investments Limited | Real estate | 2018 |
| Hirain Limited | Real estate | 2021 |
| Hire Standard Event Production Ltd | Other services | 2019 |
| Hire Steam Ltd | Administrative & support | 2016 |
| Hiren Limited | Transport & logistics | 2025 |
| Hirepaye Limited | Professional & scientific | 2019 |
| Historic Racing Drivers Club Limited | Professional & scientific | 2005 |