| Guruji Shiv Realcon Ltd | Construction | 2026 |
| Gurusai Limited | Wholesale & retail | 2026 |
| GW Builds Limited | Households | 2024 |
| Gwydyr Limited | Professional & scientific | 2018 |
| H & a Managing Services Ltd | Administrative & support | 2024 |
| H & G Glazing Limited | Construction | 2019 |
| H & H Care Homes Limited | Health & social care | 2009 |
| H Carolan Limited | Construction | 2025 |
| H J Dhillon Residential Limited | Real estate | 2023 |
| H K Caffrey Limited | Information & communication | 2011 |
| H K Odedra Ltd | Wholesale & retail | 2017 |
| H M London Ltd | Health & social care | 2008 |
| H P Technical Services Limited | Real estate | 2010 |
| H R Associates Ltd | Professional & scientific | 2022 |
| H W a Investment Properties Ltd | Real estate | 2017 |
| H&H Care Home Investments Limited | Real estate | 2007 |
| H&H Prime Properties Management Ltd | Households | 2015 |
| H&K Investment Partners Ltd | Real estate | 2026 |
| H&M Property & Investment Limited | Real estate | 2024 |
| H&M PVT Limited | Other services | 2019 |
| H&Mes Ltd | Real estate | 2024 |
| H. Martin Property Ltd | Real estate | 2016 |
| H2G Garden Tools Ltd | Wholesale & retail | 2020 |
| Haddenham Holdings Ltd | Financial services | 2024 |
| Haddenham Medicines Limited | Wholesale & retail | 2022 |
| Hadley Health Ltd | Professional & scientific | 2022 |
| Haidry Consulting Ltd | Health & social care | 2024 |
| Hairfx (London) Limited | Other services | 2013 |
| Halai Hardware & DIY Limited | Wholesale & retail | 2021 |
| Hale Watch Service Ltd | Other services | 2025 |
| Half and Half Films Ltd | Information & communication | 2025 |
| Halfdozen Holdings RTM Company Limited | Households | 2024 |
| Hall Holdings (Education) Limited | Financial services | 2017 |
| Hall Property Solutions Ltd | Real estate | 2017 |
| Hallross Ltd | Health & social care | 2011 |
| Hamam Homes Limited | Real estate | 2026 |
| Hamilton Engineering Services Ltd | Construction | 2018 |
| Hammer and Soul Carpentry Ltd | Construction | 2022 |
| Hammond&Roberts Ltd | Wholesale & retail | 2022 |
| Hampshire Pharmaceuticals Limited | Wholesale & retail | 1977 |
| Hampstead Properties Limited | Real estate | 2014 |
| Hamptons Health Limited | Other services | 2021 |
| HAN Coaching Hub Ltd | Education | 2025 |
| HAN Consultants Limited | Information & communication | 2016 |
| HAN Digipro Ltd | Real estate | 2019 |
| Hana Garment (UK) Ltd | Manufacturing | 2018 |
| Hana Garment UK1 Limited | Manufacturing | 2026 |
| Handcrafted Smiles Limited | Health & social care | 2020 |
| Handoki Ltd | Information & communication | 2015 |
| Handsale Limited | Real estate | 1987 |
| Handsale Priesty Fields Limited | Health & social care | 2020 |
| Hansaya Consulting Limited | Professional & scientific | 2009 |
| Hansaya Solutions Ltd | Information & communication | 2020 |
| Hanstar Limited | Wholesale & retail | 2009 |
| Happy Hair & Beauty Ltd | Other services | 2022 |
| Happy Mamaland Limited | Wholesale & retail | 2026 |
| Happyhostlondon Ltd | Real estate | 2021 |
| Happyhourwithk Ltd | Extraterritorial | 2021 |
| Hara Media Ltd | Information & communication | 2000 |
| Harbwr Consulting Ltd | Professional & scientific | 2019 |
| Hare Krishna (Holdings) Limited | Financial services | 2017 |
| Hare Krishnaa Enterprise Limited | Wholesale & retail | 2024 |
| Harinet Limited | Information & communication | 2015 |
| Harinu Group Ltd | Health & social care | 2023 |
| Harji Foods Limited | Wholesale & retail | 2023 |
| Harps Fitness Limited | Health & social care | 2020 |
| Harris and Company Estate Agents Limited | Real estate | 2000 |
| Harrovian Management Services Limited | Administrative & support | 1995 |
| Harrow Carpet Studios Limited | Wholesale & retail | 1972 |
| Harrow Kebab Ltd | Hospitality | 2024 |
| Harrow Kitchen Ltd | Hospitality | 2025 |
| Harrow Lighting Limited | Wholesale & retail | 2014 |
| Harrow North and South First Class Learning Ltd | Education | 2025 |
| Harrow Pizza Station Limited | Hospitality | 2021 |
| Harrow Propco Limited | Real estate | 2014 |
| Harrshiv Overseas Limited | Manufacturing | 2024 |
| Harshin Limited | Real estate | 2019 |
| Harshinu Limited | Information & communication | 2024 |
| Harshita Solution Ltd | Information & communication | 2014 |
| Hartnell Homes Ltd | Real estate | 2016 |
| Hartsbourne Estates Ltd | Real estate | 2025 |
| Harvest Moon Limited | Real estate | 2017 |
| Harvest Residential Limited | Real estate | 2019 |
| Haryom Builders Limited | Real estate | 1987 |
| Hash Bang Properties Ltd | Financial services | 2022 |
| Hashtech Consultancy Services Limited | Information & communication | 2011 |
| Hashting UK Ltd | Administrative & support | 2019 |
| Hashu Software Services Limited | Information & communication | 2017 |
| Hastings Pharma Limited | Wholesale & retail | 2026 |
| Hatch END Bakery & Deli Ltd | Wholesale & retail | 2011 |
| Hatch END Builders Ltd | Construction | 2020 |
| Hatch END Cars Limited | Transport & logistics | 2005 |
| Hatch END Eyecare Ltd | Administrative & support | 2012 |
| Hatch END Funeral Services Limited | Other services | 1998 |
| Hatch END Hardware Ltd | Wholesale & retail | 2021 |
| Hatch Training Ltd. | Professional & scientific | 2014 |
| Hatfield Home and Care Ltd | Health & social care | 2026 |
| Haute Advisory Limited | Professional & scientific | 2018 |
| Hauteluxe Ltd | Education | 2010 |
| Havardi Property Investments Ltd | Real estate | 2019 |