| Herwington Ltd | Professional & scientific | 2022 |
| Heverwood Building Services Limited | Construction | 2015 |
| Hidden Hero Limited | Health & social care | 2023 |
| Hidden Strength CYP Ltd | Education | 2022 |
| Hidden Strength Holdings Ltd | Education | 2018 |
| High Yields Ltd | Real estate | 2023 |
| Highfield Gate Management Ltd | Households | 2006 |
| Highfive Cars Limited | Wholesale & retail | 2016 |
| Highhouse Insurance Services Limited | Professional & scientific | 2005 |
| Highline Cleaning Franchise Limited | Other services | 2017 |
| Highline Pro Cleaning Limited | Other services | 2018 |
| Highway Planning Ltd | Professional & scientific | 2018 |
| Hilary Fisher Coaching Ltd | Professional & scientific | 2018 |
| Hillbrooke Limited | Professional & scientific | 2014 |
| Hillgrove House (Edgware) Management Company Limited | Households | 2021 |
| Hillmead Court Residents Association Limited | Households | 1975 |
| Hillserve Limited | Extraterritorial | 1985 |
| Hilltop Plant Limited | Wholesale & retail | 1993 |
| Hindawi Foundation | Information & communication | 2017 |
| Hire Tech Solutions Limited | Information & communication | 2009 |
| HJM Transport Ltd | Transport & logistics | 2017 |
| HMA Motors Ltd | Wholesale & retail | 2025 |
| Hnrl Consultancy Ltd | Information & communication | 2013 |
| Hobbs Close Limited | Administrative & support | 2012 |
| Hodari Data Ltd | Information & communication | 2017 |
| Holdera Ltd | Wholesale & retail | 2026 |
| Holiday Let’S Go Ltd | Households | 2022 |
| Holistic Humanitarian Pharma Limited | Health & social care | 2013 |
| Holmes for ALL Limited | Health & social care | 2021 |
| Holmes Property Partners Ltd | Real estate | 2021 |
| Holmes-Hotton (General Insurance Brokers) Limited | | 1978 |
| Holodeck AI Ltd | Wholesale & retail | 2010 |
| Home Farm Land (Radlett) Limited | Construction | 2018 |
| Home Farm Land Limited | Construction | 2017 |
| Home Guard 365 Ltd | Manufacturing | 2026 |
| Homemade Taste Food Limited | Manufacturing | 2025 |
| Homemaster Management Limited | Households | 1987 |
| Homewerks Ltd | Construction | 2026 |
| HON Records Ltd | Information & communication | 2024 |
| Honest Music Ltd | Information & communication | 2022 |
| Honour Bound Productions Ltd | Information & communication | 2023 |
| Hoofs & Hides Genuine Leather UK Limited | Wholesale & retail | 2017 |
| Hope Chiropractic Limited | Health & social care | 2025 |
| Hope Corner 1 Ltd | Hospitality | 2024 |
| Horler & Associates (Lettings) Limited | Real estate | 2006 |
| Horler Holdings Limited | Administrative & support | 2021 |
| Hot Food PIT Stop Limited | Hospitality | 2018 |
| Hot Property Investment Limited | Construction | 2015 |
| Hot Studio WSR Ltd | Arts & recreation | 2025 |
| Hotcake Ltd. | Administrative & support | 2000 |
| Hotel Inter-Continental London Limited | Hospitality | 1972 |
| Hotel Intercontinental London (Holdings) Limited | Administrative & support | 2007 |
| Hounslow Foot Clinic Limited | Health & social care | 2009 |
| House of Learning Tuition Limited | Education | 2021 |
| House Recovery Services Limited | Transport & logistics | 2025 |
| Household Container Limited | Professional & scientific | 1925 |
| Housesitters Ltd | Hospitality | 2021 |
| Housing Genie Limited | Real estate | 2016 |
| HOW to Associates Limited | Professional & scientific | 2007 |
| HP Capital Group Ltd | Real estate | 2026 |
| HPG Endurance Limited | Arts & recreation | 2016 |
| HRM Consulting Solutions Limited | Professional & scientific | 2016 |
| Hrtc Enterprises Ltd | Wholesale & retail | 2022 |
| HS Homes Property Maintenance Limited | Other services | 2019 |
| HS Properties London Ltd | Real estate | 2022 |
| HSR Transport Ltd | Transport & logistics | 2020 |
| HST Cars Limited | Wholesale & retail | 2014 |
| Hubooshi Limited | Real estate | 2017 |
| Hughes Wine & Provisions Ltd | Wholesale & retail | 2025 |
| Humadi Ltd | Real estate | 2025 |
| Human Capital Consult Ltd | Professional & scientific | 2023 |
| Humans Inc Limited | Professional & scientific | 2024 |
| Humen Home Ltd | Construction | 2025 |
| HUN Transfers and Logistics Ltd | Transport & logistics | 2017 |
| Hunger Steaks UK Ltd | Hospitality | 2025 |
| Hunter & Duke Systems Limited | Manufacturing | 2022 |
| Huntershaw Limited | Wholesale & retail | 2019 |
| Huntington Place Residents Association Limited | Administrative & support | 2000 |
| Hush Hush Beauty LLP | | 2016 |
| Huub Habets Ltd | Health & social care | 2021 |
| HW Equestrian Ltd | Agriculture & fishing | 2018 |
| Hy-Tec Automotive Ltd | Wholesale & retail | 2024 |
| Hyde Movement Ltd | Real estate | 2021 |
| Hyde Performance Limited | Health & social care | 2024 |
| Hydro Art Dynamics Limited | Professional & scientific | 2014 |
| Hyland House RTM Company Limited | Households | 2018 |
| Hyper Toy Company Limited | Wholesale & retail | 2018 |
| Hyperdrop Limited | Information & communication | 2022 |
| I B Installations Limited | Construction | 2017 |
| I D a 22 Consulting Limited | Health & social care | 2023 |
| I Liner Limited | Wholesale & retail | 2020 |
| I-Jōkō Limited | Information & communication | 2023 |
| I.R.Kk Limited | Professional & scientific | 2025 |
| I4FAY Ltd | Real estate | 2025 |
| I4RIO Ltd | Real estate | 2020 |
| IA Electrical Solutions Ltd | Professional & scientific | 2025 |
| IA Systems Limited | Wholesale & retail | 2023 |
| IA Systems Solutions Ltd | Professional & scientific | 2025 |
| Iago Associates Limited | Professional & scientific | 2006 |
| Ibex Recruitment Ltd | Administrative & support | 2018 |