| Hackett Maintenance Ltd | Construction | 2020 |
| Hadden House Management Limited | Real estate | 2015 |
| Hadleigh Court Limited | Real estate | 1996 |
| Hadleys Dairy Products Limited | Hospitality | 2000 |
| Hadlow Detailing Limited | Administrative & support | 2025 |
| Hafmurt Health Care Services Limited | Health & social care | 2017 |
| Hagad Limited | Construction | 1994 |
| Haggis and Halloumi Ltd | Health & social care | 2026 |
| Hair & Skin Solutions Limited | Other services | 2019 |
| Hair and Beauty Quality Advisers CIC | Professional & scientific | 2024 |
| Hair Artistry by Fuchsia Ltd | Other services | 2026 |
| Hair Bu'Tik Limited | Other services | 2026 |
| Hair by Holly Ltd | Other services | 2021 |
| Hair Force One Ltd | Other services | 2015 |
| Hairflair Designs Limited | Wholesale & retail | 2010 |
| Hairhut Ltd | Other services | 2017 |
| Hairy Wolves Ltd | Other services | 2025 |
| Hakerley Bridge Farm Ltd | Extraterritorial | 2024 |
| Halcro Electronics Limited | Administrative & support | 2009 |
| Halcyon Property Trading Ltd | Administrative & support | 2010 |
| Hale Letting Limited | Administrative & support | 2005 |
| Halebourne Stag Lodge Limited | Construction | 2015 |
| Halito Food Trade Ltd | Manufacturing | 2023 |
| Hall Brothers of Colchester Limited | Construction | 1966 |
| Hall Lane Limited | Professional & scientific | 2016 |
| Hallman Limited | Professional & scientific | 2014 |
| Hallmark Litho Print and Design | | 1996 |
| Halo Collectif Ltd | Manufacturing | 2026 |
| Halo Properties Limited | Construction | 2004 |
| Halsey Group Ltd | Professional & scientific | 2019 |
| Halstead and District MCC Ltd. | Arts & recreation | 2026 |
| Halstead Road 1 Limited | Construction | 2025 |
| Halstead Travel Ltd | Administrative & support | 2025 |
| HAM Communication Ltd | Construction | 2025 |
| Hambledon Carwash Ltd | Other services | 2017 |
| Hamblion Transport Limited | Transport & logistics | 1978 |
| Hamet Limited | Other services | 2019 |
| Hamilton Chase Investments Limited | Real estate | 2010 |
| Hamilton Construction and Engineering Ltd | Construction | 2022 |
| Hamilton Green Limited | Administrative & support | 2011 |
| Hamilton Manufacturing Co. Ltd | Extraterritorial | 2015 |
| Hamilton Products Limited | Manufacturing | 2019 |
| Hamilton Renovation & Construction Ltd | Construction | 2020 |
| Hamilton Servicing Ltd | Wholesale & retail | 2023 |
| Hammerbeam Oak Ltd | Manufacturing | 2018 |
| Hammy Signalling Ltd | Construction | 2024 |
| Hamperden END Homes Ltd | Construction | 2026 |
| Hampton Associates Limited | Construction | 2021 |
| Hampton Croft Ltd | Professional & scientific | 2015 |
| Hampton Park (Stanway) Residents Management Company Limited | Households | 2016 |
| Hancock Architecture Limited | Professional & scientific | 2013 |
| Hancock Industrial Abseiling Limited | Construction | 2011 |
| Handerson CM Limited | Real estate | 2019 |
| Handford Place Freehold Limited | Households | 2018 |
| Handford Place Management Limited | Households | 2004 |
| Handley Installations Limited | Construction | 2017 |
| Handmade Organics Ltd | Manufacturing | 2020 |
| Handmade Travel Limited | Administrative & support | 2005 |
| Hands & Feet Global Ltd | Other services | 2021 |
| Hands in Care Ltd | Health & social care | 2024 |
| Handstand Services Ltd | Professional & scientific | 2016 |
| Hangout Buddy Ltd | Information & communication | 2025 |
| Hanna IT Solution Limited | Information & communication | 2024 |
| Hannah Curtis Psychotherapy Limited | Health & social care | 2015 |
| Hannah Lidgate Ltd | Professional & scientific | 2016 |
| Hannah Rampton Ltd | Administrative & support | 2020 |
| Hannah S Elizabeth Ltd | Health & social care | 2019 |
| Hannaway Investments Limited | Real estate | 2009 |
| Hannibe Properties Ltd | Real estate | 2025 |
| Hanover Court Residents Association Limited | Households | 1990 |
| Hanson Properties Ltd | Financial services | 2024 |
| Hanspringett Ltd | Professional & scientific | 2020 |
| Hanuman Property Limited | Real estate | 2026 |
| Haped Limited | Administrative & support | 2016 |
| Happy Days Creative Ltd | Information & communication | 2021 |
| Happy Days Property Recovery Ltd | Water & waste | 2023 |
| Happy Home Interiors Ltd | Wholesale & retail | 2025 |
| Happy Saluki Pet Transport Ltd | Transport & logistics | 2023 |
| Happy WOK Colchester Ltd | Manufacturing | 2018 |
| Harand Rail-Train Services Ltd | Transport & logistics | 2020 |
| Harbour and Stone Limited | Financial services | 2025 |
| Hard Luck Customs Ltd | Wholesale & retail | 2024 |
| Hardie's Point Management Company Limited | Households | 2003 |
| Harding Homes (Essex) Limited | Construction | 2001 |
| Harding Homes (North Essex) Limited | Construction | 2001 |
| Harding Investment Holdings Ltd | Real estate | 2021 |
| Harding Project Solutions Limited | Construction | 2013 |
| Hardy Group Enterprises Ltd | Professional & scientific | 2024 |
| Hardy Group Network Ltd | Professional & scientific | 2024 |
| Hardy Living Ltd | Administrative & support | 2021 |
| Hardy Planners Limited | Professional & scientific | 2025 |
| Hare & Hounds (Leavenheath) Limited | Hospitality | 2017 |
| Hare & Tortoise Running Limited | Arts & recreation | 2017 |
| Hare and Hounds East Bergholt Ltd | Hospitality | 2026 |
| Harebridge Management Company Limited | Households | 2008 |
| Harfic Unlimited | Financial services | 2024 |
| Hargreaves ESQ Ltd | Manufacturing | 2020 |
| Harland Group Ltd | Construction | 2022 |
| Harland Holdings Ltd | Real estate | 2023 |
| Harling Fabrications Ltd. | Manufacturing | 1992 |