| Hair and Beauty Depot Limited | Wholesale & retail | 2025 |
| Hair DE LA Reine Ltd | Other services | 2015 |
| Hairbeau Ltd | Other services | 2020 |
| Hakimi Retail Ltd | Wholesale & retail | 2024 |
| Halai Enterprise Ltd | Real estate | 2016 |
| Halina Partners Ltd | Professional & scientific | 2025 |
| Halland Partners Limited | Administrative & support | 2025 |
| Hallmark Building Services Limited | Construction | 2019 |
| Hallmark Finance Group Limited | Financial services | 2023 |
| Hamilton Builders Limited | Construction | 2016 |
| Hammerton Carwash Ltd | Administrative & support | 2014 |
| Hammonds Properties Limited | Hospitality | 1978 |
| Hamoun Ltd | Real estate | 2007 |
| Hampstead Arts Festival | Arts & recreation | 2012 |
| Hampstead Consultants Limited | Administrative & support | 2007 |
| Hamro Guthi UK | Health & social care | 2019 |
| Handan Yinzhao Chemical Co., Ltd | Manufacturing | 2022 |
| Handy HR UK Ltd | Professional & scientific | 2022 |
| Hane Developments Ltd | Real estate | 2024 |
| Hanell Construction Ltd | Construction | 2022 |
| Hangzhou Lodora Foreign Trade Co., Ltd | Extraterritorial | 2015 |
| Hangzhou Rising Display Co., Ltd. | Extraterritorial | 2018 |
| Hanson Bennett Plasterers Ltd | Construction | 2019 |
| Hanson Care Group Ltd | Health & social care | 2019 |
| Hansvonlehwalt Consulting Limited | Information & communication | 2024 |
| Haosheng Trading Limited | Administrative & support | 2023 |
| Haoyang International Trade Co., Ltd | Extraterritorial | 2024 |
| Haoyun International Logistics Co., Ltd | Wholesale & retail | 2019 |
| Happy Pet Box Ltd | Wholesale & retail | 2017 |
| Harbi Consulting Group Ltd | Professional & scientific | 2025 |
| Hard Teaze Ltd | Wholesale & retail | 2026 |
| Hard to Reach Young People Ltd | Public administration | 2024 |
| Hardy Enterprises Limited | Construction | 2024 |
| Harefield Commercial Services Ltd | Professional & scientific | 2024 |
| Hare’S Leap (Henham) Management Company Limited | Households | 2025 |
| Hari Master Maths Tuition Ltd | Education | 2026 |
| Harihar Limited | Information & communication | 2022 |
| Harikrishna Real Estate Ltd | Real estate | 2023 |
| Harkishan Chander Limited | Extraterritorial | 2024 |
| Harlesden Health Limited | Health & social care | 2007 |
| Harleston Dental and Aesthetic Clinic Limited | Health & social care | 2023 |
| Harlington Tyres Limited | Wholesale & retail | 2020 |
| Harlow Point Limited | Real estate | 2016 |
| Harrow Homes Ltd | Health & social care | 2020 |
| Harrow Theatre Dance Limited | Arts & recreation | 2017 |
| Harrow Town Centre BID Company Limited | Administrative & support | 2009 |
| Harry's Heating Limited | Construction | 2021 |
| Hartnett Plumbing Ltd | Construction | 2024 |
| Haru Foundry Ltd | Information & communication | 2025 |
| Harvey Organization Ltd | Transport & logistics | 2025 |
| Hasheef & Co Ltd | Information & communication | 2018 |
| Hashim Asset Holdings Limited | Real estate | 2024 |
| Hashtag Prime Limited | Wholesale & retail | 2024 |
| Hasleen Enterprise Ltd | Wholesale & retail | 2025 |
| Hathi Family Capital Ltd | Professional & scientific | 2026 |
| Hathi Property Holdings Ltd | Financial services | 2026 |
| Hatia Construction Company Limited | Arts & recreation | 2025 |
| Hattusa Textile Limited | Wholesale & retail | 2023 |
| Have Brickwork Ltd | Construction | 2026 |
| Hawkes & Famili Ltd | Real estate | 2025 |
| Hawkeye Invest Ltd | Financial services | 2020 |
| Hayden Engineering Services Limited | Administrative & support | 2024 |
| Hayk Corporation Ltd | Manufacturing | 2018 |
| Hazelss Ltd | Transport & logistics | 2026 |
| HB Asset Management Limited | Real estate | 2025 |
| Hcbc Services Limited | Administrative & support | 2008 |
| Hcmg Ltd | Financial services | 2026 |
| Head and Heart Empowerment Ltd | Construction | 2021 |
| Headstone Associates Kensington Ltd | Wholesale & retail | 2025 |
| Headstone Associates Limited | Wholesale & retail | 2015 |
| Headstone Associates London Ltd | Wholesale & retail | 2023 |
| Headstone Tennis Coaching Ltd | Education | 2026 |
| Healing 2 Harmonise Ltd | Health & social care | 2024 |
| Health Care Bridge Ltd | Health & social care | 2023 |
| Health Spirit Ltd | Other services | 2020 |
| Healthcaps Europe Ltd | Wholesale & retail | 2018 |
| Healthwatch Intl Ltd | Manufacturing | 2024 |
| Heatherwood Nursing Home Ltd | Health & social care | 2008 |
| Heatmap Ltd | Information & communication | 2020 |
| Hebei Oriental Hardware Co., Limited | Wholesale & retail | 2018 |
| Hebei Zerun Electric Power Fitting Co ., Ltd | Administrative & support | 2023 |
| Hedge Hawk Capital Ltd | Information & communication | 2024 |
| Hedgestone Investment Limited | Information & communication | 2021 |
| Heirmakeup Ltd | Other services | 2018 |
| Hellenitech Ltd | Information & communication | 2023 |
| Helloklean Ltd | Wholesale & retail | 2020 |
| HEM55 Ltd | Hospitality | 2025 |
| Hema Photography Ltd | Arts & recreation | 2016 |
| Hengfeng Co., Ltd | Wholesale & retail | 2019 |
| Hengguang New Material Co., Ltd | Wholesale & retail | 2024 |
| Henley London UK Ltd | Other services | 2016 |
| Henley Williams Limited | Real estate | 2020 |
| Hephaestus S B Sales Limited | Other services | 2022 |
| Heritage Lane Ltd | Wholesale & retail | 2025 |
| Heritage of Camden Ltd | Administrative & support | 2020 |
| Heritage Roofing & Building Solutions Limited | Construction | 2014 |
| Heritage Roofing and Building Limited | Construction | 2021 |
| Heronuk Ltd | Information & communication | 2017 |
| Herts & London Inventory Services Ltd | Administrative & support | 2017 |
| Herts and Bucks Limited | Administrative & support | 2006 |