| Harlock Contracts Limited | Professional & scientific | 2018 |
| Harlock Properties Ltd | Real estate | 2024 |
| Harmony Homes (Essex) Ltd | Real estate | 2022 |
| Harmony Hotels Limited | Hospitality | 2024 |
| Harmony Landscapes & Driveways Ltd | Construction | 2024 |
| Harmonymedcare Ltd | Administrative & support | 2018 |
| Harness the Passion Ltd | Construction | 2024 |
| Harnser Property Limited | Real estate | 2018 |
| Harp Design Limited | Professional & scientific | 2020 |
| Harp Interiors Limited | Wholesale & retail | 2025 |
| Harpait Design & Build Limited | Construction | 2018 |
| Harper Charles Company Ltd | Manufacturing | 2019 |
| Harper Charles Holdings Ltd | Real estate | 2023 |
| Harper Lifestyle Limited | Manufacturing | 2008 |
| Harri Care Ltd | Health & social care | 2022 |
| Harrie Brown & Co Ltd | Financial services | 2014 |
| Harris & Harrison Ltd | Manufacturing | 2018 |
| Harris Building Co. Limited | Construction | 2013 |
| Harris Vasquez Limited | Real estate | 2026 |
| Harrison Childs Co Limited | Other services | 2025 |
| Harrison Clyde Ltd | Information & communication | 2022 |
| Harrison Grace Consulting Ltd | Professional & scientific | 2023 |
| Harrison Structural Holdings Ltd | Professional & scientific | 2010 |
| Harrison Structural Waterproofing Consultants Ltd | Construction | 2012 |
| Harrison UK Limited | Real estate | 1995 |
| Harrison Waterproofing Limited | Administrative & support | 2006 |
| Harrow Business Services Limited | Wholesale & retail | 2010 |
| Harry Alexander Flooring Ltd | Wholesale & retail | 2021 |
| Harry Gozzett Ltd | Arts & recreation | 2021 |
| Harryosa Deepcleans Ltd | Administrative & support | 2022 |
| Hart and Whitewater Properties Limited | Real estate | 2022 |
| Hart Veterinary Services Ltd | Professional & scientific | 2018 |
| Hartcopy Ltd. | Professional & scientific | 2022 |
| Hartington RD Ltd | Real estate | 2023 |
| Hartland Estates Ltd | Real estate | 2021 |
| Hartman Construction Ltd | Construction | 2022 |
| Harts Flooring Ltd | Construction | 2017 |
| Harts Leap (Sandhurst) Limited | Professional & scientific | 1999 |
| Harts Transport Management Limited | Transport & logistics | 2021 |
| Harvard Court (Highwoods) Management Company Limited | Households | 1986 |
| Harvey Gallagher Associates Limited | Real estate | 2014 |
| Harvey Gallagher Group Limited | Financial services | 2022 |
| Harvey Gallagher Residential Limited | Real estate | 2025 |
| Harwich Kindertransport Learning Ltd | Education | 2023 |
| Harwich Kindertransport Memorial and Learning Trust Limited | Education | 2020 |
| Harwich Road Management Company Limited | Administrative & support | 2018 |
| Hasina Choudhury Limited | Financial services | 2022 |
| Hasler Place Limited | Households | 2003 |
| Haste Property Finance Limited | Financial services | 2020 |
| Haswell Moulding Technologies Limited | Manufacturing | 2000 |
| HAT Projects Limited | Professional & scientific | 2007 |
| HAT Properties Limited | Real estate | 2017 |
| Hatfields Furnishers (Stanway) Limited | Wholesale & retail | 1976 |
| Hatfields Furnishers Limited | Professional & scientific | 1975 |
| Hatfields Limited | Extraterritorial | 2000 |
| Hatherley Grange Limited | Health & social care | 2016 |
| Hatt East of E Ltd | Hospitality | 2026 |
| Hatt Projects Limited | Real estate | 2017 |
| Hattie Stewart Illustration Limited | Arts & recreation | 2014 |
| Hatton Berry Investments LLP | | 2021 |
| Hatton Solar Farm Limited | Energy | 2021 |
| Hatton Street Property Partners (Iberia) Limited | Real estate | 2015 |
| Hatton Street Property Partners Limited | Real estate | 2015 |
| Have Words Limited | Professional & scientific | 2012 |
| Haven Edge Services Limited | Construction | 2025 |
| Haven Occupational Health Limited | Health & social care | 2010 |
| Havering Womens AID | Hospitality | 2002 |
| Havey Solutions Limited | Transport & logistics | 1998 |
| Havillah-Care Limited | Administrative & support | 2023 |
| Havn Systems Ltd | Wholesale & retail | 2025 |
| Hawker Softeners Limited | Manufacturing | 2002 |
| Hawkins and Woolley Homes Ltd | Real estate | 2024 |
| Hawkins Road Colchester Management Limited | Households | 2006 |
| Hawkshaw Agency Ltd | Financial services | 2025 |
| Hawksmoor Construction Services Limited | Construction | 2007 |
| Hawksridge Heating Ltd | Construction | 2024 |
| Hawthorn Close (Bicknacre) Management Company Limited | Households | 2022 |
| Hawthorn Consultancy Services Limited | Administrative & support | 2019 |
| Hawthorn Executive PA Ltd | Administrative & support | 2019 |
| Hawthorns Estate Limited | Administrative & support | 2024 |
| Hayes Scaffolding Limited | Administrative & support | 2014 |
| Hayfields Downham Market Residents Management Company Limited | Households | 2013 |
| Hayley's Salon Ltd | Other services | 2017 |
| Haynes Carpentry Essex Limited | Construction | 2021 |
| Haynow Limited | Wholesale & retail | 2023 |
| Hayward & Barrett Holdings Limited | Professional & scientific | 2011 |
| Hayward Chemist Limited | Wholesale & retail | 2001 |
| Hazel Associates Limited | Administrative & support | 2015 |
| Hazelwood CP Ltd | Real estate | 2015 |
| Hazelwood DP Ltd | Real estate | 2024 |
| Hazelwood Family LLP | | 2022 |
| Hazelwood UK Limited | Administrative & support | 2009 |
| HB Building & Property Services Ltd | Construction | 2019 |
| HB Partners Mortgage & Protection Ltd | Financial services | 2018 |
| HBA Healthcare Limited | Health & social care | 2025 |
| HBH Carpentry Ltd | Manufacturing | 2018 |
| HBL Property Development Limited | Real estate | 2007 |
| HC Paving Ltd | Construction | 2016 |
| HC Veterinary Services Ltd | Professional & scientific | 2016 |
| Hc&I Limited | Administrative & support | 2010 |