| Gustav Studio Ltd | Wholesale & retail | 2023 |
| Gustus Ltd | Hospitality | 2026 |
| Gx.Ai Limited | Information & communication | 2023 |
| Gyaan Labs Ltd | Information & communication | 2022 |
| Gyaan Research Labs Ltd | Information & communication | 2020 |
| H Recovery Ltd | Transport & logistics | 2025 |
| H.E.L.M. Network Ltd | Administrative & support | 2023 |
| Haasvi Limited | Information & communication | 2012 |
| Habitus Capital Limited | Financial services | 2017 |
| Hackney Supermarket Ltd | Wholesale & retail | 2019 |
| Hadid Company Ltd | Real estate | 2015 |
| Hadley ST James Cleaning Limited | Administrative & support | 2016 |
| Hadley St.James Limited | Professional & scientific | 1987 |
| Hagthorn House Limited | Real estate | 2018 |
| HAI Industries Limited | Manufacturing | 2025 |
| Haidex Trade Ltd | Wholesale & retail | 2026 |
| Hairvan Ltd | Other services | 2023 |
| Haks Consulting Limited | Information & communication | 2010 |
| Halcyon Living 11 Limited | Health & social care | 2015 |
| Halcyon Living Holdings 11 Ltd | Financial services | 2022 |
| Halcyon Living Holdings 111 Ltd | Financial services | 2022 |
| Halcyon Living Holdings 1V Ltd | Financial services | 2022 |
| Halcyon Living Holdings Limited | Financial services | 2019 |
| Halcyon Living IV Ltd | Health & social care | 2021 |
| Half Mexican Ltd | Other services | 2025 |
| Halfway UP Productions Ltd | Information & communication | 2023 |
| Hall Real Estate Limited | Real estate | 2014 |
| Hallde Limited | Professional & scientific | 1993 |
| Halle Investment Group Ltd | Financial services | 2023 |
| Hallington Ventures Ltd | Financial services | 2023 |
| Halo Consultants Limited | Professional & scientific | 2018 |
| HAM and North Kingston Community Investors CIC | Real estate | 2017 |
| HAM Car Wash Ltd | Other services | 2026 |
| Hamadryad Ltd | Manufacturing | 2014 |
| Hamilton Goodfellow Limited | Real estate | 2021 |
| Hamish James Associates Limited | Professional & scientific | 2025 |
| Hampden House Properties Limited | Real estate | 2015 |
| Hamper Agency Ltd | Professional & scientific | 2023 |
| Hampton Bespoke Garden Rooms Ltd | Construction | 2021 |
| Hampton Wick History Ltd | Information & communication | 2018 |
| Hamza BIN HYE Ltd | Wholesale & retail | 2026 |
| Hanang (UK) Limited | Administrative & support | 2025 |
| Handpicked Management Limited | Professional & scientific | 2006 |
| Handschuhe UN Limited | Wholesale & retail | 2020 |
| Handsel House Limited | Wholesale & retail | 2023 |
| Handymanbud Ltd | Construction | 2015 |
| Hannaby & Hannaby Lets Ltd | Real estate | 2016 |
| Hannah Lewis Global Ltd | Professional & scientific | 2017 |
| Hanrow Sales Limited | Professional & scientific | 1994 |
| Hanscomb Ltd | Professional & scientific | 2022 |
| Hanway Place Limited | Households | 1991 |
| Haomom Consultancy Ltd | Information & communication | 2019 |
| Happer Education Ltd | Education | 2017 |
| Happy Home Shop Limited | Information & communication | 2024 |
| Happy Hugs Ltd | Wholesale & retail | 2019 |
| Happy Life Properties Limited | Households | 2025 |
| Happy Selling Ltd | Professional & scientific | 2017 |
| Harbex Limited | Health & social care | 1995 |
| Harbour Intelligence Ltd | Information & communication | 2026 |
| Hardcourt Limited | Professional & scientific | 1993 |
| Hardwick House (Oxshott) Limited | Households | 2022 |
| Harel Holdings Limited | Financial services | 2016 |
| Harfinn Services Ltd | Construction | 2025 |
| Harmes Limited | Wholesale & retail | 2010 |
| Harmony AI Ltd | Information & communication | 2021 |
| Harmony of Hearts International Ltd | Education | 2018 |
| Harmony Therapies Ltd | Other services | 2025 |
| Harpercollar Ltd | Professional & scientific | 2024 |
| Harris Enterprise Group Ltd | Wholesale & retail | 2026 |
| Harrison Homes & Developments Ltd | Construction | 2018 |
| Harrison Homes (U.K) Ltd | Real estate | 2022 |
| Harrison Jacks Ltd | Real estate | 2021 |
| Harrison Jake Holdings Limited | Financial services | 2023 |
| Hartedge Limited | Real estate | 1990 |
| Hartlander UK Developments Limited | Real estate | 2020 |
| Harvard Finance Limited | Financial services | 2024 |
| Harvellous Ltd | Wholesale & retail | 2026 |
| Harvey Installations Ltd | Construction | 2024 |
| Harvio Ltd | Wholesale & retail | 2025 |
| Hastoe Capital PLC | Financial services | 2012 |
| Hastoe Homes Limited | Construction | 2011 |
| Hauck International Equestrian Legal Services Ltd | Professional & scientific | 2018 |
| Havenroot Limited | Wholesale & retail | 2024 |
| Havilah Global Holdings Ltd | Financial services | 2025 |
| Hawaii Energy Limited | Energy | 2019 |
| Hawe Baron & Co Limited | Wholesale & retail | 2005 |
| Hawker Court (Queens Road) Residents Association RTM Company Ltd | Households | 2005 |
| Hawks Partners Limited | Wholesale & retail | 2014 |
| Haya Plus Ltd | Real estate | 2025 |
| Hayden & Baker Ltd | Wholesale & retail | 2022 |
| Hayden's Place Management Limited | Households | 1992 |
| Hayman Collective Limited | Professional & scientific | 2017 |
| HB Capital Investments Limited | Real estate | 2017 |
| HB Capital Limited | Financial services | 2017 |
| HB Industrial Limited | Real estate | 2022 |
| HB Solutions Ltd | Construction | 2025 |
| HBI Estates Limited | Real estate | 2021 |
| HCW Exterior Cleaning Ltd | Administrative & support | 2026 |
| Heal Kids Foundation Ltd | Administrative & support | 2008 |
| Health & Corporate Solutions Limited | Administrative & support | 2016 |