| H a & K Properties Ltd | Real estate | 2026 |
| H Contemporary Limited | Professional & scientific | 2020 |
| H Contractor Ltd | Construction | 2026 |
| H Fisher Accounting Services Ltd | Professional & scientific | 2017 |
| H M S Heating Services Limited | Construction | 2023 |
| H&8 J&T Enterprise Ltd | Wholesale & retail | 2025 |
| H&D Emart Limited | Wholesale & retail | 2026 |
| H&M Fitness Limited | Arts & recreation | 2024 |
| H&W Group Ltd | Health & social care | 2024 |
| H.& F.Farrell,Limited | Construction | 1934 |
| H.& M.Barnett Limited | Real estate | 1963 |
| HA7 Investments Ltd | Other services | 2017 |
| Haalom Saliza Nordic Trading Limited | Hospitality | 2016 |
| Haber Nominees Limited | Professional & scientific | 2005 |
| Habs Property Ltd | Real estate | 2018 |
| Hachi Consulting Ltd | Professional & scientific | 2024 |
| Hackney Development Limited | Real estate | 2017 |
| Hacon Studio Ltd | Other services | 2007 |
| Hadaf Persian School Ltd | Education | 2015 |
| Hadley Gardens Limited | Construction | 2021 |
| Haedy Limited | Real estate | 2016 |
| Hala London Ltd | Manufacturing | 2018 |
| Hala London Production Limited | Information & communication | 2020 |
| Hala London Property Limited | Real estate | 2021 |
| Hala World Ltd | Financial services | 2019 |
| Halai Holdings Limited | Administrative & support | 1994 |
| Half Moon Properties Limited | Real estate | 1993 |
| Hall House Prep London Limited | Education | 2025 |
| Hall Residence Limited | Real estate | 2023 |
| Halligan Build Ltd | Construction | 2025 |
| Hallys & Co Limited | Professional & scientific | 2014 |
| Halsbury Management Ltd | Real estate | 2021 |
| Hambrig Investments Limited | Real estate | 1964 |
| Hamilton & Hargreaves Properties Limited | Real estate | 2017 |
| Hamilton Nexus Ltd | Administrative & support | 2023 |
| Hamilton Portman Limited | Other services | 2018 |
| Hamlet House RTM Company Limited | Extraterritorial | 2014 |
| Hamonde Park (One) Edgware Management Company Limited | Households | 1993 |
| Hampden Meadow Management Limited | Households | 1997 |
| HAN Fire Limited | Professional & scientific | 2024 |
| Hand, Hair and Beauty Ltd | Other services | 2011 |
| Hands on Gear Ltd | Wholesale & retail | 2024 |
| Hanger Hill Freehold Co NO1 Ltd | Real estate | 2022 |
| Hanisha Pharma Consultancy Ltd | Wholesale & retail | 2024 |
| Haniyya Foundation Ltd | Health & social care | 2024 |
| Hanlon DRY Lining Limited | Construction | 2020 |
| Hanmec Limited | Wholesale & retail | 2005 |
| Hanniel Foods Limited | Hospitality | 2020 |
| Hans Accounting Limited | Professional & scientific | 2004 |
| Hans Solutions Limited | Real estate | 2017 |
| Hans Technology Limited | Information & communication | 2008 |
| Hans&Co FM Ltd | Construction | 2018 |
| Haoua's Cakes & Cupcakes Limited | Hospitality | 2025 |
| Happy Chatters Limited | Education | 2019 |
| Happy Feet Club Limited | Wholesale & retail | 2025 |
| Happy Pets VET Services Limited | Professional & scientific | 2019 |
| Happy Seven Holdings | Financial services | 2024 |
| Haraz Service Limited | Transport & logistics | 2024 |
| Hardey Kassam Associates Ltd | Financial services | 2003 |
| Hardy Mews (Uxbridge) Management Company Limited | Real estate | 2007 |
| Hari OM Builders Limited | Construction | 2015 |
| Haria Logistics and Commerce Ltd | Transport & logistics | 2022 |
| Haridham Enterprise Ltd | Information & communication | 2021 |
| Harihar Consultancy Ltd | Professional & scientific | 2019 |
| Harikrushna Container MFG Ltd | Administrative & support | 2024 |
| Harisumiran Ltd | Wholesale & retail | 2023 |
| Hark Development Ltd | Real estate | 2025 |
| Harlequin D&B Limited | Construction | 2021 |
| Harlow Bowl Limited | Arts & recreation | 2011 |
| Harmal Dost Ltd | Wholesale & retail | 2025 |
| Harmal Solutions Ltd | Wholesale & retail | 2025 |
| Harmless IT Consulting Ltd | Information & communication | 2017 |
| Harmony Day Spa Ltd | Other services | 2020 |
| Harmonyprime Limited | Public administration | 2024 |
| Harnam Construction Ltd | Construction | 2013 |
| Harnam Developers Limited | Real estate | 2017 |
| Harrington Wilson Limited | Information & communication | 2007 |
| Harrison Fish Law Ltd | Professional & scientific | 2023 |
| Harrow Accountants and Tax Advisors Ltd | Professional & scientific | 2015 |
| Harrow Financial Ltd | Professional & scientific | 2023 |
| Harrow Padel Ltd | Arts & recreation | 2026 |
| Harrow Properties Limited | Real estate | 2017 |
| Harrow RFC Supporters Limited | Arts & recreation | 2026 |
| Harrow Rugby Football Club Limited | Arts & recreation | 2025 |
| Harrow Weald Investments Limited | Construction | 1983 |
| Harry K & H Properties Limited | Construction | 2014 |
| Harry K. & H. Construction Co. Limited | Construction | 1986 |
| Harry's People Ltd | Professional & scientific | 2012 |
| Harsan & Co Limited | Hospitality | 2026 |
| Hartmead Finance Limited | Financial services | 1988 |
| Hartswood Invest Services Limited | Wholesale & retail | 2014 |
| Hartswood Limited | Professional & scientific | 2003 |
| Hartswood Textiles Limited | Construction | 2016 |
| Hartwell Energy Advisory Ltd | Professional & scientific | 2026 |
| Harvenius Orbital Ltd | Construction | 2008 |
| Harvest TEC Ltd | Wholesale & retail | 2023 |
| Harvey Hazel Limited | Administrative & support | 2014 |
| HAS & Co. Limited | Professional & scientific | 2023 |
| Hassans Restaurant Limited | Hospitality | 1997 |
| Hast Homes Ltd | Real estate | 2024 |