| Hammer Cross Solutions Limited | Financial services | 2025 |
| Hammers Rigging Limited | Construction | 2021 |
| Hams Estate Ltd | Real estate | 2023 |
| Hams Technology Ltd | Information & communication | 2016 |
| Hamtechroofing Ltd | Construction | 2018 |
| HAN Meat Ltd | Wholesale & retail | 2026 |
| Hanbury Health Limited | Other services | 2025 |
| Hanbury Health MK Limited | Other services | 2026 |
| Hancia Limited | Transport & logistics | 2017 |
| Hand Print Finishers Ltd | Other services | 2016 |
| Handa Construction (London) Ltd | Construction | 2016 |
| Handa Property Invest Ltd | Real estate | 2024 |
| Handley Gardening Services Ltd | Administrative & support | 2025 |
| Handmade by Tinni Limited | Manufacturing | 2020 |
| Hands of Humanity UK Trust | Education | 2023 |
| Hands on Homes Maintenance Ltd | Construction | 2023 |
| Handyman Ultra Pro MAX Ltd | Construction | 2026 |
| Haneny Private Limited | Wholesale & retail | 2021 |
| Haniloba Limited | Real estate | 2022 |
| Hanique Ltd | Wholesale & retail | 2024 |
| Hanly Quarries (UK) Limited | Construction | 2010 |
| Hanson Grey Ltd | Construction | 2018 |
| Hansons Building Contractors Limited | Construction | 2015 |
| Hanspec Limited | Financial services | 2026 |
| Hanu Foods Ltd | Wholesale & retail | 2023 |
| Hapi Flow Limited | Wholesale & retail | 2023 |
| Happy Blissful Homes Ltd | Real estate | 2021 |
| Happy Deals Ltd | Wholesale & retail | 2025 |
| Happy EDI Trans Ltd | Transport & logistics | 2022 |
| Happy Hearts Childminding Ltd | Health & social care | 2024 |
| Happy Ride CAB Ltd | Transport & logistics | 2025 |
| Happy UK Kids Ltd | Health & social care | 2021 |
| Happygems Limited | Health & social care | 2015 |
| HAQ Courier Service Ltd | Transport & logistics | 2025 |
| HAQ Real Estate Ltd | Real estate | 2025 |
| Haque International Ltd | Administrative & support | 2023 |
| HAR Consultancy Services Ltd | Information & communication | 2020 |
| HAR Developments Limited | Real estate | 2017 |
| HAR Group Limited | Hospitality | 2025 |
| HAR Holdings Limited | Financial services | 2020 |
| HAR Properties Surrey Limited | Real estate | 2019 |
| Harborstone Limited | Wholesale & retail | 2025 |
| Hardcore Engineering Ltd | Information & communication | 2026 |
| Hardec WET Rooms Ltd | Construction | 2020 |
| Hardeep Kainth Limited | Professional & scientific | 2015 |
| Hardeep Kainth Property Limited | Real estate | 2019 |
| Harding Bros. Electrical Limited | Construction | 1975 |
| Hardwood Flooring Ltd | Wholesale & retail | 2007 |
| Hares Hire Services Limited | Administrative & support | 2005 |
| Harkness Close (Harold Hill) Management Limited | Households | 1981 |
| Harleen Dhanju Services Ltd | Administrative & support | 2022 |
| Harlen Development & Construction Consulting Limited | Construction | 2026 |
| Harlequin Specialist Child & Adolescent Mental Health Services Ltd | Health & social care | 2014 |
| Harlie Briggs Limited | Professional & scientific | 2024 |
| Harlow Road Holdings Limited | Financial services | 2019 |
| Harno Construction Ltd | Construction | 2024 |
| Harold Cafe Ltd | Hospitality | 2024 |
| Harold Crownrich Estates Ltd | Real estate | 2023 |
| Harold Handy Ltd | Construction | 2015 |
| Harold News Limited | Wholesale & retail | 2023 |
| Harold Staff Reinforcement Ltd | Manufacturing | 2013 |
| Harold Wood Electrical Limited | Construction | 2018 |
| Harold Wood PRE School Limited | Education | 2018 |
| Harold Wood Properties Limited | Real estate | 1995 |
| Harold Wood Property Ltd | Households | 2024 |
| Haroon Akhtar Ltd | Health & social care | 2014 |
| Harp Consulting Limited | Professional & scientific | 2011 |
| Harpar Developments Limited | Real estate | 2020 |
| Harpar Properties Limited | Construction | 2020 |
| Harpers TMS and Event Management Ltd | Arts & recreation | 2021 |
| Harpreet Singh Ltd | Construction | 2026 |
| Harrier Investments Ltd | Real estate | 2020 |
| Harriet Ellis Training Solutions Limited | Administrative & support | 2008 |
| Harris Innovations Ltd | Professional & scientific | 2014 |
| Harris Land and Developments Limited | Real estate | 2026 |
| Harris Maintenance and Cleaning Ltd | Administrative & support | 2022 |
| Harrison Investments London Limited | Administrative & support | 2023 |
| Harrison Wipers Limited | Administrative & support | 2012 |
| Harrison Wipes Limited | Administrative & support | 2012 |
| Harrison Wiping Limited | Manufacturing | 2012 |
| Harron Holdings Limited | Wholesale & retail | 2022 |
| Harry Prod Limited | Transport & logistics | 2013 |
| Harry's Bar & Restaurant Limited | Hospitality | 2020 |
| Harsanad Property Limited | Real estate | 2023 |
| Harsh Premium Ltd | Hospitality | 2026 |
| Hart Agency Limited | Administrative & support | 2017 |
| Hart Projects Limited | Construction | 2006 |
| Harts Lane (Block B) Management Co. Limited | Households | 1985 |
| Harvey’S Investment & Management Ltd | Real estate | 2024 |
| Harwood Building Services Limited | Construction | 2012 |
| Hasan Contractor Limited | Professional & scientific | 2025 |
| Hasan Shahzad Ltd | Wholesale & retail | 2023 |
| Hasan's Innovation Ltd | Hospitality | 2024 |
| Hasani Construction Ltd | Construction | 2022 |
| Hash Engineering Consultants Ltd | Extraterritorial | 2012 |
| Hashhr Ltd | Information & communication | 2023 |
| Hashmed Ltd | Health & social care | 2013 |
| Hashtag Loaded Kitchen Ltd | Hospitality | 2026 |
| Hashtag Loaded Ltd | Hospitality | 2023 |
| Hasi TBS Ltd | Construction | 2022 |