| Guideline Publications Ltd | Information & communication | 1994 |
| GVA Consultancy Ltd | Administrative & support | 2025 |
| GYF Drylining Ltd | Manufacturing | 2021 |
| H & M Cake Designs Limited | Wholesale & retail | 2006 |
| H & Y Socials Limited | Information & communication | 2025 |
| H Ayeni Ltd | Transport & logistics | 2024 |
| H C S Pipework Services Limited | Construction | 2016 |
| H K Trading Limited | Wholesale & retail | 1995 |
| H R Housing Ltd | Real estate | 2021 |
| H Singh Properties Limited | Real estate | 2021 |
| H&N Transport Ltd | Transport & logistics | 2017 |
| H.K Lalwani Ltd | Wholesale & retail | 2025 |
| H.P. Maintenance Services Ltd | Construction | 2018 |
| H20 Print Management Limited. | Other services | 2005 |
| H2MP Ltd | Professional & scientific | 2021 |
| H2O Kitchen & Bathroom Designs Ltd | Wholesale & retail | 2026 |
| Hadara Limited | Wholesale & retail | 2023 |
| Hadiya Living Ltd | Wholesale & retail | 2026 |
| Hadrian Academy Trust | Education | 2011 |
| Haelen Healthcare Limited | Health & social care | 2017 |
| Haflan Resources Limited | Wholesale & retail | 2021 |
| Haggle Ride Ltd | Transport & logistics | 2025 |
| Haiduc Engineering Limited | Construction | 2019 |
| Hair 4 U Ltd | Other services | 2022 |
| Hair Experience Limited | Other services | 2014 |
| Hair Motion Ltd | Education | 2019 |
| Hair Virtue Ltd | Other services | 2021 |
| Hajir Bari Limited | Wholesale & retail | 2014 |
| Halani Investment Group Ltd | Financial services | 2025 |
| Halflane Capital Ltd | Professional & scientific | 2022 |
| Halls Garden and Plant Machinery Sales Ltd | Manufacturing | 2026 |
| Halls Garden Machinery Ltd | Wholesale & retail | 2022 |
| Halo Property Limited | Real estate | 2023 |
| Halooda Games Ltd | Information & communication | 2024 |
| Hammernik Limited | Construction | 2012 |
| Hampshire Parks Ltd | Hospitality | 2025 |
| HAN Enterprise Ltd | Hospitality | 2024 |
| Hanbury Consulting Services Ltd | Professional & scientific | 2024 |
| Hancock & Hastings Limited | Professional & scientific | 2017 |
| Handling Equipment Sales Ltd | Wholesale & retail | 1991 |
| Hands of Help CIC | Hospitality | 2025 |
| Handycon Ltd | Administrative & support | 2019 |
| Hang Hing Limited | Real estate | 2023 |
| Hansra Wheeler Ltd | Transport & logistics | 2018 |
| Happy Face Childminding Ltd | Health & social care | 2025 |
| Happy Hermit Home Ltd | Extraterritorial | 2024 |
| Haptivate Ltd | Education | 2018 |
| Hara Ceylon Ltd | Wholesale & retail | 2025 |
| Harbourmark Ltd | Professional & scientific | 2026 |
| Hardall Construction Limited | Professional & scientific | 1987 |
| Hardall Holdings Limited | Professional & scientific | 1990 |
| Hardall International Limited | Manufacturing | 1987 |
| Hardsurface Carpentry & Joinery Ltd | Manufacturing | 2024 |
| Harlee&Haylee Care Ltd | Health & social care | 2022 |
| Harley Communications Limited | Information & communication | 2022 |
| Harlington Property Services Limited | Real estate | 2023 |
| Harlow Barrington Builders Limited | Construction | 2020 |
| Harlow Barrington Buildings Ltd | Construction | 2026 |
| Harlow House Limited | Households | 2025 |
| Harmony Home Care Limited | Health & social care | 2026 |
| Harmony Surfaces UK Limited | Wholesale & retail | 2024 |
| Harmonycare Associates Ltd | Health & social care | 2023 |
| Harpenden House Management Company Limited | Households | 2017 |
| Harris & Jones Limited | Manufacturing | 2021 |
| Harris Coachworks Limited | Wholesale & retail | 2002 |
| Harrison Maxwell Architects Ltd | Professional & scientific | 2026 |
| Harrisons Carpentry Ltd | Other services | 2026 |
| Harry's of Winslow Limited | Wholesale & retail | 2020 |
| Harvey Carpets & Flooring Ltd | Wholesale & retail | 2022 |
| Harvey Longcroft Limited | Real estate | 2019 |
| Hasan Equity Holdings Ltd | Households | 2025 |
| Hasan Property Ltd | Real estate | 2025 |
| Hastings Kibens Limited | Real estate | 2025 |
| Hasvada Ltd | Hospitality | 2022 |
| Hatfield Park Close (Management NO. 2) Limited | Households | 1976 |
| Hatfield Park Close (Management) Limited | Households | 1976 |
| Hattie's Box Limited | Hospitality | 2023 |
| HAURES1984 Ltd | Construction | 2021 |
| Havona Estates Limited | Real estate | 2023 |
| Hawa Estate Limited | Real estate | 2026 |
| Hawkersartisan Ltd | Wholesale & retail | 2025 |
| Hawkes & Smart Limited | Professional & scientific | 2017 |
| Hawkes Building Limited | Construction | 2016 |
| Hawksmill Denim Company Limited | Professional & scientific | 2014 |
| Hawley Gift Shop Ltd | Wholesale & retail | 2024 |
| Haydex Limited | Extraterritorial | 2013 |
| Haykay Educational Consults Ltd | Professional & scientific | 2026 |
| Hayley Rail Solutions Ltd | Professional & scientific | 2020 |
| Haynes Recovery Ltd | Wholesale & retail | 2022 |
| Hazel Court, Hitchin (Maintenance) Limited | Households | 1976 |
| Hazelmart Ltd | Wholesale & retail | 2025 |
| HCI Consultants Limited | Administrative & support | 2008 |
| HD Interiors Ltd | Construction | 2024 |
| Head Property Investments Limited | Real estate | 2025 |
| Headgal Ltd | Hospitality | 2022 |
| Headline Social Limited | Professional & scientific | 2025 |
| Headstrong Consulting Ltd | Administrative & support | 2019 |
| Heartbeat Consultancy Limited | Health & social care | 2013 |
| Heat Cool Tech Ltd | Construction | 2020 |
| Heather Rose Ltd | Health & social care | 2024 |