| Haslam Property Finance Limited | Professional & scientific | 2025 |
| Haslar Yacht Services Ltd | Extraterritorial | 2016 |
| Hasom Limited | Health & social care | 2019 |
| Hassanaqib Limited | Wholesale & retail | 2023 |
| Haste Solutions Ltd | Administrative & support | 2024 |
| Hasten Properties Limited | Real estate | 2020 |
| HAT - Trick Academy Ltd | Wholesale & retail | 2022 |
| HAT Construction Solutions Limited | Education | 2025 |
| Hatch Ltd | Professional & scientific | 2026 |
| Hathaway House Holdings Limited | Real estate | 2021 |
| Hatley Court Residents Limited | Other services | 2002 |
| Hatstep Limited | Wholesale & retail | 2025 |
| Haven Contracts Ltd | Wholesale & retail | 2021 |
| Haven Grill Ltd | Hospitality | 2024 |
| Haven Unity Limited | Real estate | 2020 |
| Havengoods Ltd | Wholesale & retail | 2023 |
| Havenrock Living Ltd | Real estate | 2025 |
| Havenx Ltd | Wholesale & retail | 2024 |
| Havering Beauty Clinic Limited | Other services | 2021 |
| Havering Business Education Partnership Limited | Education | 1992 |
| Havering Care Provider Group Ltd | Health & social care | 2019 |
| Havering Citizens Advice Bureaux | Other services | 1991 |
| Havering Estates Limited | Real estate | 2025 |
| Havering Health Ltd | Health & social care | 2014 |
| Havering Health Rooms Ltd | Real estate | 2026 |
| Havering Healthwatch C.I.C. | Public administration | 2013 |
| Havering Hotel Ltd | Hospitality | 2023 |
| Havering London Limited | Education | 2024 |
| Havering Ltd | Real estate | 2023 |
| Havering Museum Limited | Arts & recreation | 2001 |
| Havering Muslim Community Ltd | Health & social care | 2024 |
| Havering Roofing and Building Ltd | Construction | 2021 |
| Havie Services Limited | Administrative & support | 2021 |
| Havilah Prospects Limited | Education | 2005 |
| Hawkridge Close Residents Association Limited | Real estate | 1975 |
| Haworta Limited | Real estate | 2022 |
| Hayaat Life Sciences Ltd | Wholesale & retail | 2024 |
| Hayat Legacy Properties Ltd | Real estate | 2025 |
| Hayati Vape Experts Limited | Wholesale & retail | 2026 |
| Haybourne Limited | Real estate | 2021 |
| Haydens Facilities Limited | Administrative & support | 2000 |
| Haydon Hair Ltd | Other services | 2022 |
| Hayperspective Ltd | Information & communication | 2025 |
| Haz&Co Real Estate Ltd | Financial services | 2025 |
| Hazaq Consulting Ltd | Professional & scientific | 2009 |
| Hazeleigh House RTM Company Ltd | Households | 2024 |
| Hazelwood Golf Ltd | Wholesale & retail | 2023 |
| Hazlemere Property Improvements Limited | Construction | 2019 |
| HBG by Eugene Ltd | Construction | 2021 |
| HBI Healthcare Services Ltd | Health & social care | 2018 |
| HBJ Enterprises Ltd | Wholesale & retail | 2026 |
| HBK Trade Limited | Manufacturing | 2012 |
| HC Consultancy Services Ltd | Professional & scientific | 2023 |
| Hcap Limited | Information & communication | 2020 |
| HCL Insurance BPO Services Limited | Financial services | 2004 |
| HD Abode Ltd | Real estate | 2023 |
| HD Capital Ltd | Information & communication | 2020 |
| HD Enterprises Limited | Other services | 2013 |
| HDH Transport Ltd | Transport & logistics | 2025 |
| Hdin Engineering Limited | Construction | 2025 |
| HDM IT Consultancy Limited | Information & communication | 2024 |
| HE Expertise Consultancy Ltd | Education | 2025 |
| HE Reigns Electrical & Building Services Limited | Extraterritorial | 2020 |
| He&D Limited | Construction | 2011 |
| Head Office Developments Ltd | Real estate | 2024 |
| Heads on Beds London Limited | Real estate | 2018 |
| Headway (London) Limited | Financial services | 2002 |
| Healing Echoes Limited | Information & communication | 2022 |
| Health Balance Ltd | Wholesale & retail | 2025 |
| Health IS Life With Support Group Community Interest Company | Hospitality | 2025 |
| Health on Wheels Ltd | Education | 2020 |
| Health Services at Home Ltd | Health & social care | 2023 |
| Healthcare PCT Limited | Administrative & support | 2009 |
| Healthy Abode Ltd | Professional & scientific | 2010 |
| Hear Hear Limited | Health & social care | 2018 |
| Heart Health and More Limited | Health & social care | 2019 |
| Heart Health Consultancy Limited | Professional & scientific | 2025 |
| Heart Health Investments Limited | Real estate | 2025 |
| Heart of BEN Limited | Health & social care | 2025 |
| Hearts & Hands Support Ltd | Health & social care | 2026 |
| Heath Care Children Services Ltd | Health & social care | 2024 |
| Heath Maintenance Ltd | Construction | 2024 |
| Heath Park Barbers Limited | Other services | 2014 |
| Heath Ventilation Ltd | Construction | 2019 |
| Heathbury Limited | Other services | 2016 |
| Heathive Services Limited | Construction | 2025 |
| Heathurst Property Co.Limited | Administrative & support | 1955 |
| Heating Zone Ltd | Construction | 2025 |
| Heatix Ltd | Construction | 2025 |
| Heatpower Limited | Construction | 2015 |
| Heaven Residentials Ltd | Real estate | 2025 |
| Heavenly Scent Candles Limited | Manufacturing | 2024 |
| Hebzen Media Limited | Other services | 2020 |
| Hedingham Homes Limited | Real estate | 1991 |
| Hedon Properties Limited | Real estate | 2021 |
| Heena Fabrics Ltd | Construction | 2016 |
| Heerstone Ltd | Real estate | 2025 |
| Heffalump Limited | Information & communication | 2016 |
| HEH Ltd | Construction | 2006 |
| Hela Constructions Ltd | Construction | 2025 |