| HLJ Construction Limited | Construction | 2025 |
| HLW Properties & Renovations Ltd | Real estate | 2022 |
| HM Healthcare Ltd | Health & social care | 2014 |
| HM Property Solutions Limited | Administrative & support | 2016 |
| HM Sohn Limited | Health & social care | 2024 |
| HMI Design Ltd | Professional & scientific | 2025 |
| HMO Invest Limited | Construction | 2016 |
| HMO Property Sourcing Limited | Real estate | 2014 |
| Hmwf Limited | Manufacturing | 2016 |
| HN Print Ltd | Manufacturing | 2019 |
| HNK Partners Limited | Construction | 2018 |
| Hobsons Decor Ltd | Construction | 2024 |
| Hocus Pocus Mortgages Limited | Financial services | 2019 |
| Hoda Medical Consultancy Ltd | Health & social care | 2020 |
| Holdar Contracts Ltd | Transport & logistics | 2023 |
| Holden Property Management Limited | Real estate | 2017 |
| Holkham Education Ltd | Professional & scientific | 2026 |
| Hollybrook (1) Management Company Limited | Households | 1995 |
| Holmdale Management Limited | Professional & scientific | 2019 |
| Holme Place Freeholders Limited | Households | 2021 |
| Holvia Ltd | Health & social care | 2026 |
| Holywell ROW Management Company Limited | Real estate | 2020 |
| Home Accommodation Limited | Real estate | 2023 |
| Home Improvements for Today Ltd | Manufacturing | 2025 |
| Home Improvements Today (Trade) Limited | Manufacturing | 2011 |
| Home of Amare Ltd | Information & communication | 2022 |
| Home of Amare Studios Ltd | Information & communication | 2024 |
| Home of Physio Limited | Health & social care | 2012 |
| Homegrown Recruitment Limited | Administrative & support | 2026 |
| Homehab Ltd | Health & social care | 2021 |
| Homelea Maintenance Limited | Construction | 2009 |
| Homerun Global Entertainment Ltd | Manufacturing | 2020 |
| Homes by Bethel CIC | Real estate | 2023 |
| Homes by Houghton Ltd | Real estate | 2023 |
| Honest Legacy Limited | Health & social care | 2023 |
| Honest Riders Ltd | Wholesale & retail | 2018 |
| Hong Quan Ltd | Real estate | 2023 |
| Hong Stays Limited | Hospitality | 2025 |
| Hoop Hustle Flow Ltd | Arts & recreation | 2021 |
| Hoopers Plumbing and Heating Ltd | Construction | 2024 |
| Hoor Corporation Limited | Wholesale & retail | 2024 |
| Hope & Haven Limited | Administrative & support | 2016 |
| Hope Care Support Limited | Health & social care | 2017 |
| Hopper Media Ltd | Other services | 2023 |
| Hops Solutions Ltd | Construction | 2014 |
| Horizon Investments Holdings Ltd | Financial services | 2018 |
| Horizon Land Limited | Real estate | 2000 |
| Horizon Primary Care Ltd | Health & social care | 2025 |
| Horizon Technology Park Management Company Limited | Real estate | 2000 |
| Hornsey International Limited | Administrative & support | 2025 |
| Hornsmill Ventures Limited | Professional & scientific | 2021 |
| Horton Industries Ltd | Manufacturing | 2021 |
| Hosanna Homes Ltd | Real estate | 2021 |
| Hospitality Operations Specialists Limited | Professional & scientific | 2025 |
| Host VFX Ltd | Other services | 2017 |
| Hotel Employers Group CIC | Other services | 2020 |
| House and Beds Cleaning Services Ltd | Administrative & support | 2026 |
| House Number Two Ltd | Administrative & support | 2023 |
| House of ARO Ltd | Manufacturing | 2025 |
| House of Colour International Limited | Financial services | 2008 |
| House of Colour Limited | Other services | 1985 |
| House of Glam (Stevenage) Ltd | Other services | 2024 |
| House of MUD Ltd | Information & communication | 2024 |
| Howard Creative Limited | Professional & scientific | 2014 |
| Howard Management Solutions Limited | Professional & scientific | 2012 |
| Howarde Court Residents Limited | Real estate | 2014 |
| Howards END Management Services Limited | Other services | 2008 |
| HP Group Services Ltd | Professional & scientific | 2022 |
| HP Tuners Europe Ltd | Wholesale & retail | 2019 |
| HRK Roofing Limited | Construction | 2024 |
| HRS Property Group Ltd | Real estate | 2023 |
| HSK Food Limited | Wholesale & retail | 2022 |
| HSM Services Ltd | Construction | 2022 |
| Hsne Limited | Other services | 2014 |
| HTM Driveways and Patios Ltd | Construction | 2024 |
| Hubro Bioscience Ltd | Health & social care | 2025 |
| Huddle Careers Ltd | Administrative & support | 2016 |
| Hudson ASH Limited | Construction | 2013 |
| Hudson IT Ltd | Information & communication | 2011 |
| Hughes/Gardner Cleaning & Support Services Limited | Other services | 1973 |
| HUH Holdings Limited | Financial services | 2025 |
| Huma Global Limited | Professional & scientific | 2011 |
| Humphreys Removals & Storage Limited | Transport & logistics | 2019 |
| Hunt Electrical (Hertfordshire) Ltd | Construction | 2024 |
| Hunters and Unicorns Limited | Other services | 2020 |
| Hunters Oak Management Company NO. 1 Limited | Households | 1985 |
| Huong Viet Supermarket Limited | Wholesale & retail | 2026 |
| Huongviet Supermarket UB7 Limited | Wholesale & retail | 2022 |
| Hurren (Stevenage) Limited | Wholesale & retail | 1983 |
| Hurune Limited | Health & social care | 2019 |
| Huss Holdings Ltd | Financial services | 2023 |
| Hussain Engineering Services Limited | Professional & scientific | 2022 |
| Hussein Taki Orthopaedics Ltd | Health & social care | 2025 |
| Huxley Services Ltd | Professional & scientific | 2026 |
| HVS Structure Group Limited Limited | Construction | 2026 |
| HW Brickwork Limited | Construction | 2016 |
| Hybrid Post Hub Ltd | Manufacturing | 2024 |
| Hyde Cafe & Takeaway Ltd | Hospitality | 2024 |
| Hygea Medical Healthcare Ltd | Health & social care | 2023 |
| Hyjo Limited | Administrative & support | 2011 |