| Gym Twin Limited | Extraterritorial | 2024 |
| H & G Holdings '93 Ltd | Extraterritorial | 2018 |
| H Nash Ltd | Construction | 2023 |
| H&H Electrical Limited | Construction | 2017 |
| H.F.A.Dolman Limited | Construction | 1957 |
| H.Q. Property Limited | Real estate | 2011 |
| Hackney Smoke Ltd | Wholesale & retail | 2022 |
| Hair by Cloe Ltd | Other services | 2017 |
| Hair Mane 67 Limited | Other services | 2025 |
| Hall & Lee-Jones Properties Ltd | Construction | 2022 |
| Hands on Location Ltd | Administrative & support | 2024 |
| Handyman Jack Services Ltd | Construction | 2016 |
| HAP Homes Ltd | Real estate | 2026 |
| Happy Holiday Homes Ltd | Hospitality | 2024 |
| Happy Relocations Limited | Real estate | 2021 |
| Happy Services London Ltd | Water & waste | 2020 |
| Hardska Ltd | Wholesale & retail | 2012 |
| Harold Hill Foot Clinic Limited | Health & social care | 2015 |
| Harpar Investments Ltd | Real estate | 2024 |
| Harper by Design Limited | Construction | 2024 |
| Harvey Catering Services Ltd | Hospitality | 2018 |
| Haus of AM Ltd | Real estate | 2026 |
| Haus of Blonde Ltd | Other services | 2023 |
| Haus of Lengths Ltd | Wholesale & retail | 2026 |
| Haus of London Limited | Administrative & support | 2016 |
| Having Agency Ltd | Manufacturing | 2023 |
| Hawsted Residents Association Limited | Households | 1987 |
| HB Hairdressing Ltd | Other services | 2025 |
| HBD Europe Limited | Wholesale & retail | 1991 |
| HBD International Limited | Wholesale & retail | 2018 |
| HBD Properties Limited | Real estate | 2013 |
| Heathaze Limited | Real estate | 2014 |
| Heindrick Becker Limited | Administrative & support | 2018 |
| Helevision Ltd | Information & communication | 2021 |
| Hendon Heights Ltd | Real estate | 2019 |
| Herding Cats Productions Ltd | Information & communication | 2026 |
| Heron Property Investments (UK) Limited | Real estate | 2011 |
| Heyden & SON Limited | Wholesale & retail | 2013 |
| HFK Wealth Management Ltd | Financial services | 2021 |
| HGG Socials Ltd | Information & communication | 2026 |
| HH Féluna Ltd | Wholesale & retail | 2015 |
| Hidden Security Limited | Other services | 2009 |
| Highview Venture Ltd | Real estate | 2022 |
| Hill Smile Academy Limited | Other services | 2011 |
| Hillkam Investments Limited | Financial services | 2017 |
| Hinton House Ltd | Administrative & support | 2017 |
| HIP HOP Heals Ltd. | Education | 2026 |
| HJ North Estate Ltd | Real estate | 2021 |
| Hobart Court Residents Association Limited | Households | 1980 |
| Hobarts - Alexandra Park Ltd. | Real estate | 2005 |
| Holetown Properties Limited | Real estate | 2018 |
| Holtmon Jones Ltd | Financial services | 2020 |
| Holtmon-Jones Recruitment Ltd | Administrative & support | 2024 |
| Holy Ghost Adoration Ministry (UK) Ltd | Professional & scientific | 2021 |
| Home Living Services Limited | Construction | 2023 |
| Homefield Limited | Administrative & support | 2021 |
| Honeysums Holster Limited | Other services | 2013 |
| Hooked on Events Ltd | Administrative & support | 2015 |
| Hoptimistic Pubs Ltd | Hospitality | 2025 |
| Hoque Consultancies Limited | Professional & scientific | 2017 |
| Horizontrade Hub Ltd | Information & communication | 2024 |
| House of Akme Ltd | Professional & scientific | 2024 |
| House of Siren Ltd | Arts & recreation | 2026 |
| Houses and Homes UK Limited | Real estate | 2018 |
| Hovend Limited | Construction | 1997 |
| Howells Property Investor Ltd | Financial services | 2025 |
| Hrpc Investments Limited | Other services | 2012 |
| HSR Investment Properties Limited | Real estate | 2025 |
| HSR Legal Services Limited | Administrative & support | 2013 |
| HSR Solicitors Limited | Professional & scientific | 2024 |
| Hudexus Ltd | Professional & scientific | 2026 |
| Hulver Management Limited | Households | 2019 |
| Hunt Marine Salvage / Firefighting Ltd | Public administration | 2026 |
| Hushaboo Limited | Other services | 2013 |
| HUT Architecture Limited | Professional & scientific | 2006 |
| HUT Capital Holdings Ltd | Real estate | 2026 |
| Hvac Crafters Ltd | Construction | 2025 |
| I & H Q Ltd | Real estate | 2017 |
| I AM Manifesting Limited | Wholesale & retail | 2023 |
| I Mwanja Ltd | Construction | 2025 |
| Iceni Court Residents Association Limited | Households | 2008 |
| Ideal Creations Ltd | Wholesale & retail | 2021 |
| IG87 Drylining Team Ltd | Construction | 2023 |
| Igniteenergyafrica Ltd | Professional & scientific | 2020 |
| Imaan by Nohad Ltd | Wholesale & retail | 2019 |
| Image Developments Limited | Real estate | 2004 |
| Imagine and Grow Childcare Limited | Health & social care | 2022 |
| Impact Lending (Croydon) Limited | Construction | 2026 |
| Impact Lending Limited | Financial services | 2019 |
| Impact Working Ltd | Real estate | 2020 |
| Improvement Management Solution Ltd | Construction | 2022 |
| Inc PAD Limited | Other services | 2008 |
| Indonesia Consultancy Services Limited | Professional & scientific | 2008 |
| Infinite Learning Limited | Education | 2005 |
| Infinitely Beyond Ltd | Real estate | 2017 |
| Infinity Engineering Solutions Ltd | Professional & scientific | 2019 |
| Influence Furniture Ltd | Manufacturing | 2020 |
| Ingram Associates Limited | Professional & scientific | 2003 |
| Ingram Developments Limited | Professional & scientific | 2019 |
| Inner City Grassroots Limited | Arts & recreation | 2026 |