| Gyamglo Limited | Real estate | 2024 |
| Gymnasticsfm Limited | Education | 2023 |
| Gyntas Construction and Maintenance Ltd | Construction | 2019 |
| Gypsum Masters Ltd | Construction | 2025 |
| GZ Building Services Ltd | Construction | 2026 |
| H & a Textiles Ltd | Wholesale & retail | 2024 |
| H & I Real Estate Ltd | Real estate | 2023 |
| H & M General Construction Builder Ltd | Construction | 2024 |
| H & Q Cafe Shop Limited | Hospitality | 2018 |
| H Bethel Care Ltd | Health & social care | 2021 |
| H&A Mandate Ltd | Other services | 2015 |
| H&D Consultants Ltd | Professional & scientific | 2022 |
| H&D Property Holdings Ltd | Real estate | 2025 |
| H&D Watford Ltd | Wholesale & retail | 2025 |
| H&O Motors Ltd | Transport & logistics | 2017 |
| H&P4U Limited | Construction | 2021 |
| H&S Kotarja Ltd | Construction | 2026 |
| H&S Takeaway Ltd | Hospitality | 2026 |
| H. Smith (Smithfield) Limited | Wholesale & retail | 1946 |
| H.A.D Support Ltd | Administrative & support | 2023 |
| H.E.M Rigging Limited | Professional & scientific | 2023 |
| H.L.Hawes & SON Limited | Other services | 1939 |
| H.L.M Construct Ltd | Construction | 2023 |
| H2A2 Estates Ltd | Real estate | 2025 |
| H3A Traders Ltd | Wholesale & retail | 2024 |
| H7 Avenue Ltd | Hospitality | 2020 |
| HA Meem Trading UK Ltd | Wholesale & retail | 2023 |
| HA Preet Development Limited | Real estate | 2026 |
| Haak Management Ltd | Real estate | 2020 |
| Habib Arif & Sons Limited | Wholesale & retail | 2016 |
| Habir UK Ltd | Wholesale & retail | 2025 |
| Habitation of Praise Evangelistic Ministries | Other services | 2024 |
| Hackman & Co Ltd | Professional & scientific | 2026 |
| Hackney Meat Traders Ltd | Manufacturing | 2012 |
| Hadaye Limited | Real estate | 2019 |
| Hafiz Holding Group Ltd | Financial services | 2026 |
| Haftheartist Ltd | Wholesale & retail | 2026 |
| HAI JI Grocery Delivery Ltd | Wholesale & retail | 2012 |
| Haig Park Healthcare Limited | Health & social care | 2021 |
| Hair and Surf Lounge Limited | Other services | 2012 |
| Hair Affairs Beauty Salon Ltd | Other services | 2024 |
| Hair and Beauty by Trio Ltd | Other services | 2020 |
| Hairbless Studio Ltd | Other services | 2021 |
| Hajrah Homes Ltd | Real estate | 2020 |
| Halafia Investments Limited | Wholesale & retail | 2025 |
| Halal Food Information Centre UK Ltd | Hospitality | 2021 |
| Halil Portland Tyres Ltd | Administrative & support | 2019 |
| Halleluyah Gate Ministries Ltd | Other services | 2015 |
| Halomamu Limited | Health & social care | 2023 |
| Hamaji & Co Ltd | Wholesale & retail | 2024 |
| Hamedis Ltd | Wholesale & retail | 2022 |
| Hamida Distributions Ltd | Wholesale & retail | 2025 |
| Hammad X Ltd | Wholesale & retail | 2024 |
| Hamse Ahmed Optics Limited | Professional & scientific | 2022 |
| Hamza Malik Ltd | Wholesale & retail | 2023 |
| Hanbury International Ltd | Professional & scientific | 2025 |
| Hand Window Cleaning Urban & Homes Ltd | Administrative & support | 2025 |
| Handdr Projects Ltd | Construction | 2025 |
| Handysim Ltd | Transport & logistics | 2025 |
| Hani Crafts Ltd | Wholesale & retail | 2025 |
| Hani Transport Ltd | Water & waste | 2021 |
| Hannah and Michael Door to Door Services Limited | Transport & logistics | 2009 |
| Hanshu Consultancy Services Limited | Information & communication | 2020 |
| Hanza Travel Group Limited | Transport & logistics | 2026 |
| Hapi Stuff Ltd | Wholesale & retail | 2021 |
| Happy Builders London Ltd | Other services | 2025 |
| Happy Mirror Ltd | Administrative & support | 2019 |
| Happy OT Ltd | Wholesale & retail | 2023 |
| Happy-Home Brands UK Ltd | Wholesale & retail | 2024 |
| Happynest Living Ltd | Real estate | 2026 |
| HAQ Construction Ltd | Construction | 2023 |
| Haque Agency Limited | Professional & scientific | 2025 |
| Hargun Properties Limited | Real estate | 2024 |
| Hari and SRI Stores Ltd | Wholesale & retail | 2022 |
| Hari Sports Limited | Wholesale & retail | 2024 |
| Harika Construction Ltd | Construction | 2023 |
| Haris Corp Limited | Wholesale & retail | 2021 |
| Haris Khalid Co Limited | Wholesale & retail | 2022 |
| Harleybstitches Ltd | Other services | 2019 |
| Harman Logistics Ltd | Transport & logistics | 2026 |
| Harmony Christian Ministries | Other services | 1999 |
| Harmony Community Projects | Administrative & support | 2009 |
| Harringay Meats UK Ltd | Wholesale & retail | 2017 |
| Harris Flooring Limited | Construction | 2000 |
| Harry & Morgs Consultancy Ltd | Professional & scientific | 2026 |
| Hartanah UK Ltd | Real estate | 2024 |
| Hasbaya Trading Ltd | Wholesale & retail | 2025 |
| Hash Solutions Limited | Information & communication | 2018 |
| Hasmujaj Ltd | Real estate | 2025 |
| Hassan Ventures Ltd | Administrative & support | 2025 |
| Hatfield Maintenance Ltd | Construction | 2025 |
| Hatfield Mews (Management) Limited | Real estate | 2004 |
| Hatsmith Ltd | Wholesale & retail | 2025 |
| Hausofoyin Ltd | Administrative & support | 2026 |
| Haven Energy Solutions Limited | Construction | 2025 |
| Haven Homes & Rentals Ltd | Hospitality | 2024 |
| Haven Network Ltd | Arts & recreation | 2025 |
| Haven Playhaus Ltd | Hospitality | 2025 |
| Havering Engineering Supplies Limited | Manufacturing | 2004 |
| Havering Kitchens Ltd | Construction | 2025 |