| Harold Fairclough (Heating) Limited | | 1941 |
| Harriet Louise Productions Ltd | Arts & recreation | 2024 |
| Harrington Baxter Solutions Limited | Administrative & support | 2012 |
| Harris Tweed BED Company Ltd | Manufacturing | 2022 |
| Harris Tweed Furniture Company Ltd | Manufacturing | 2022 |
| Harrison & Brown Furniture Limited | Wholesale & retail | 2017 |
| Harry Burnicle Electrical Contractors Limited | Construction | 1997 |
| Harry Marsh (Engineers) Limited | Construction | 1972 |
| Harry Thursby Holdings Limited | Professional & scientific | 2016 |
| Harry Thursby Limited | Wholesale & retail | 2006 |
| Harrys Barcade Ltd | Hospitality | 2023 |
| Hartlepool Marine Servicing Company Limited | Manufacturing | 1963 |
| Hartley Scaffolding Ltd | Construction | 2026 |
| Harvey Patton Ltd | Real estate | 2021 |
| Hasa Agency Limited | Administrative & support | 2018 |
| Hassi NE Ltd | Hospitality | 2023 |
| Hasso Salon Ltd | Other services | 2023 |
| Haswell&Son Roofing and Cladding Ltd | Construction | 2021 |
| Hatmore Ltd | Real estate | 2021 |
| Hatton Services (NE) Limited | Administrative & support | 2020 |
| Haus XIV Ltd | Wholesale & retail | 2025 |
| Haven Villas Limited | Real estate | 2026 |
| Havenfield Limited | Wholesale & retail | 2025 |
| Havenhome Properties Ltd | Construction | 2025 |
| Havillah Studios Ltd | Professional & scientific | 2025 |
| Hawick Locums Limited | Wholesale & retail | 2023 |
| Hays Beds Limited | Administrative & support | 2001 |
| Hays Foreign Exchange Limited | Administrative & support | 1996 |
| Hays Property Services Limited | Real estate | 1934 |
| Hays Tour Operating Limited | Administrative & support | 1998 |
| Hays Transfers Limited | Administrative & support | 2007 |
| Hays Transport Limited | Administrative & support | 2007 |
| Hays Travel Foundation | Administrative & support | 2014 |
| Hays Travel Group Limited | Financial services | 2025 |
| Hays Travel Limited | Administrative & support | 1986 |
| Haze Group & Events Ltd | Administrative & support | 2025 |
| HBR Consultants Ltd | Professional & scientific | 2022 |
| HCA Litigation Limited | Administrative & support | 2014 |
| Hcar Consulting Ltd | Professional & scientific | 2023 |
| HCC Property North East Limited | Real estate | 2025 |
| HCP Property Investment Ltd | Real estate | 2023 |
| HD Kitchens NE Ltd | Construction | 2023 |
| HD Sun Group Ltd | Other services | 2024 |
| Headline Home Improvements Ltd | Construction | 2025 |
| Headway Business Support Limited | Professional & scientific | 2025 |
| Heal the Word Ltd | Professional & scientific | 2025 |
| Healthwatch Sunderland Ltd | Extraterritorial | 2011 |
| Healthy Habit's N.E Ltd | Other services | 2023 |
| Heart Warriors Foundation CIC | Other services | 2025 |
| Hearts Creative Projects Community Interest Company | Health & social care | 2019 |
| Hearty Made Food Limited | Other services | 2023 |
| Heathfield (Amenity Areas) Limited | Households | 1976 |
| Heathland Windfarm Partnership LLP | | 2010 |
| Heatland Stoves Ltd | Construction | 2015 |
| Heavywheelsrepair Ltd | Wholesale & retail | 2026 |
| Hedleys Solicitors (Sunderland) Ltd | Professional & scientific | 2020 |
| Heirloom Properties Limited | Real estate | 2023 |
| Helders Healthcare Limited | Information & communication | 2025 |
| Helen Russell Photography Ltd | Professional & scientific | 2017 |
| Hello Wrld Ltd | Information & communication | 2025 |
| Henderson Butchers Limited | Wholesale & retail | 2016 |
| Henderson Butchers NE Ltd | Wholesale & retail | 2025 |
| Henderson Insurance (NE) Limited | Financial services | 2010 |
| Henderson Properties North East Ltd | Real estate | 2024 |
| Hendon Fast Food Ltd | Hospitality | 2022 |
| Hendon Homes Management Company Limited | Hospitality | 2025 |
| Hendon Jami Masjid Ltd | Education | 2023 |
| Hendon OFF Licence Ltd | Wholesale & retail | 2022 |
| Henry James Software Limited | Information & communication | 2025 |
| Heplink Ltd | Professional & scientific | 2025 |
| Hepwood Digital Limited | Information & communication | 1998 |
| Heritage Car & Classic Ltd | Wholesale & retail | 2025 |
| Heritage Windows NE Ltd Limited | Manufacturing | 2024 |
| Herra Fibre Limited | Information & communication | 2021 |
| Herrenknecht International Limited | Construction | 1984 |
| Herrington Industrial Services Limited | Administrative & support | 1987 |
| Herrington IT Consultancy Services Limited | Information & communication | 2021 |
| Herrington Kitchens & Bedrooms Limited | Construction | 2026 |
| Herrington Landscapes Ltd | Administrative & support | 2022 |
| Herrington Training Academy Limited | Other services | 2015 |
| Herron Demolition Ltd | Construction | 2011 |
| Herron Developments Ltd | Real estate | 2008 |
| Hetianshidai Ltd | Wholesale & retail | 2025 |
| Hewitt Renewable Energy Services Ltd | Administrative & support | 2022 |
| HEY Jinni Ltd | Professional & scientific | 2022 |
| Heyrose Developments Ltd | Real estate | 2025 |
| HFS Group Ltd | Administrative & support | 2022 |
| HG Civils Ltd | Construction | 2026 |
| HH Decorators Ltd | Construction | 2017 |
| HHV Switching Ltd | Professional & scientific | 2025 |
| HI Performance (Holdings) Limited | Professional & scientific | 2019 |
| Hicks Maintainance Ltd | Manufacturing | 2018 |
| Hidiah Foodstore Ltd | Wholesale & retail | 2023 |
| Higgins Property Lettings Limited | Real estate | 2026 |
| High Barnes Housing Ltd | Real estate | 2021 |
| High Bridge Corporate Services Limited | Financial services | 2008 |
| High Newport Allotments Ltd | Agriculture & fishing | 2019 |
| High Street Pizza Ltd | Hospitality | 2026 |
| High Volt Garage Limited | Wholesale & retail | 2021 |
| Highcrest Homes (North East) Ltd | Construction | 2016 |