| Hina Opulent Ltd | Hospitality | 2025 |
| Hipas Ltd | Professional & scientific | 2021 |
| Hiray Cars Ltd | Wholesale & retail | 2017 |
| Histon Medicines Ltd | Wholesale & retail | 2025 |
| HKM Consulting Limited | Information & communication | 2010 |
| Hkptl Consulting Limited | Professional & scientific | 2025 |
| Hksa Southampton Ltd | Hospitality | 2020 |
| Hksa Trading Limited | Hospitality | 2016 |
| HM Curtain Limited | Wholesale & retail | 2024 |
| HM Harmony Care Ltd | Health & social care | 2025 |
| Hm&C Ltd | Wholesale & retail | 2021 |
| HN Cooling Ltd | Energy | 2023 |
| HNA London Ltd | Transport & logistics | 2022 |
| HNW Holdings Limited | Financial services | 2021 |
| Hodson Associates Limited | | 1983 |
| Holistic Business Excellence Ltd | Administrative & support | 2024 |
| Hollowgill Ltd | Health & social care | 2026 |
| Home Climate & Plumbing Service Ltd | Construction | 2020 |
| Home Comforts Property Limited | Real estate | 2019 |
| Home Quality Inspections Ltd | Construction | 2020 |
| Homecare Comforts Limited | Health & social care | 2019 |
| Homefield Capital Holdings Limited | Extraterritorial | 2012 |
| Homefield Resourcing Limited | Health & social care | 2014 |
| Honest Real Estate Limited | Real estate | 2023 |
| Honeybee Cars Ltd | Administrative & support | 2019 |
| Hoorma Investments Limited | Real estate | 2014 |
| Horological Hatchery Limited | Wholesale & retail | 2018 |
| Hospital Performance Index (HPI) Ltd | Information & communication | 2026 |
| Hospitality Network International Ltd | Information & communication | 2024 |
| Hot Bakes Ltd | Hospitality | 2024 |
| Hothouse BIZ Limited | Professional & scientific | 2000 |
| Hotrocks Food & Drink Ltd | Hospitality | 2019 |
| House DES Doner Ltd | Hospitality | 2025 |
| House of Laser London Limited | Other services | 2022 |
| Housix Ltd | Water & waste | 2018 |
| Houss Clothing Ltd | Wholesale & retail | 2026 |
| HOW to WIN Ltd | Administrative & support | 2020 |
| Howden Plumbing and Heating Ltd | Construction | 2016 |
| HR 655 Limited | Hospitality | 2022 |
| HR Kickstart Ltd | Administrative & support | 2020 |
| Hrbs Global Ltd | Administrative & support | 2023 |
| Hristovi & Sons Limited | Wholesale & retail | 2012 |
| Hrugner Limited | Construction | 2018 |
| HS Capital Ltd | Health & social care | 2025 |
| HS Holdings London Ltd | Real estate | 2025 |
| Hshk Capital Ltd | Real estate | 2025 |
| Htwglobal Ltd | Information & communication | 2025 |
| Hudson Security Limited | Administrative & support | 2016 |
| HUM Gold Ltd | Information & communication | 2016 |
| Human Advantage Education Ltd | Professional & scientific | 2026 |
| Humble Cleaners Home & Office Services Ltd | Administrative & support | 2023 |
| Hungry Habibi Grill Ltd | Hospitality | 2026 |
| Huntley Close Management Company Limited | Real estate | 2008 |
| Hurlston Limited | Professional & scientific | 2016 |
| Hurlstone Limited | Real estate | 2020 |
| Hurst River Limited | Construction | 2025 |
| Hvac Engineering Ltd | Manufacturing | 2024 |
| HW and BV Properties Limited | Real estate | 2017 |
| HWX Consulting Ltd | Professional & scientific | 2021 |
| HYA Ltd | Administrative & support | 2013 |
| Hybrid International Group Ltd | Information & communication | 2023 |
| Hydrogen Plumbing and Heating Ltd | Construction | 2021 |
| HYE Opulent Ltd | Hospitality | 2025 |
| Hymenaios Ltd | Professional & scientific | 2020 |
| Hyper Technologies Limited | Manufacturing | 2012 |
| Hyperstrata Limited | Information & communication | 2016 |
| Hyphen INT Company Ltd | Wholesale & retail | 2025 |
| Hyprr Films Ltd | Information & communication | 2021 |
| HYS Builders Ltd | Construction | 2019 |
| HZA London Ltd | Transport & logistics | 2019 |
| I a Mian Ltd | Administrative & support | 2017 |
| I M Housing Ltd | Real estate | 2023 |
| I M Plumbing & GAS Engineering Limited | Construction | 2018 |
| I Union of Pakistani Students CIC | Education | 2022 |
| I.J. & S.C. Fernandes and Associates Limited | Health & social care | 2026 |
| Ianua Market Limited | Professional & scientific | 2017 |
| IB Eco Laundry Ltd | Other services | 2019 |
| IBB Traders Ltd | Wholesale & retail | 2021 |
| Ibex Driving School Ltd | Education | 2020 |
| Ibex Films Limited | Arts & recreation | 2016 |
| Ibraheem Investments Corporation Ltd | Real estate | 2021 |
| Ibranding Limited | Construction | 2014 |
| Ibzi Tech Ltd | Professional & scientific | 2023 |
| Ice Cream Wala Ltd | Wholesale & retail | 2020 |
| Icetank Limited | Real estate | 2015 |
| ICH Trading Ltd | Transport & logistics | 2016 |
| Iconic Properties Investors Ltd | Real estate | 2022 |
| Iconic Properties Ventures Ltd | Real estate | 2025 |
| Icostyle Ltd | Administrative & support | 2014 |
| ICT Partnerships Limited | Information & communication | 2002 |
| ICU Ltd | Administrative & support | 2017 |
| ID Property Solutions Ltd | Construction | 2021 |
| Ideal London Tyres Ltd | Wholesale & retail | 2017 |
| Ideal Property Investment Ltd | Real estate | 2020 |
| Ideal Repair & Maintenance Ltd | Wholesale & retail | 2016 |
| Ideal Tyres London Ltd | Wholesale & retail | 2016 |
| Idfn Investments Ltd | Real estate | 2021 |
| Idtnaine Limited | Other services | 2013 |
| IG Solution & Services Ltd | Other services | 2024 |
| Ignite Fmcg Ltd | Professional & scientific | 2025 |