| House of Media and Culture CIC | Education | 2024 |
| Housetreks Ltd | Wholesale & retail | 2023 |
| Howson Wood Ltd | Wholesale & retail | 2010 |
| HP Sweet UK Ltd | Hospitality | 2024 |
| Hpmnt Limited | Real estate | 2024 |
| HPT Construction Ltd | Manufacturing | 2025 |
| Hrma MED Ltd | Wholesale & retail | 2022 |
| HS DIY Limited | Wholesale & retail | 2024 |
| Hs-One Traders Ltd | Wholesale & retail | 2023 |
| HSB Construction Services Ltd | Construction | 2023 |
| HSD Property Ltd | Real estate | 2021 |
| HSL Contracts Ltd | Information & communication | 2015 |
| Hsmk Limited | Construction | 2022 |
| HT Pharmaceuticals Limited | Wholesale & retail | 2023 |
| Huaze Investments Limited | Real estate | 2023 |
| Huaze Limited | Hospitality | 2022 |
| Hugo Services Ltd | Construction | 2019 |
| Human Particle Engineering Research Association | Professional & scientific | 2025 |
| Human Race Medical Services Ltd | Health & social care | 2011 |
| Hummingbird International Limited | Information & communication | 2012 |
| Hundal Cottage Limited | Real estate | 2025 |
| Hunter Sierra Property Ltd | Construction | 2020 |
| Huobi Electrical Ltd | Construction | 2025 |
| Huobi Property Holdings Ltd | Real estate | 2023 |
| Hupotasso Ltd | Professional & scientific | 2020 |
| Husky Heaven Therapy C.I.C. | Health & social care | 2025 |
| Huvaad Ltd | Administrative & support | 2017 |
| Huzzi Ltd | Wholesale & retail | 2026 |
| Hvac Bash Ltd | Manufacturing | 2022 |
| Hybrid & Electric Centre Ltd | Wholesale & retail | 2025 |
| Hybrid Centre UK Ltd | Wholesale & retail | 2025 |
| Hybrid Energy Global Drone Space Construction Technology Ltd | Professional & scientific | 2025 |
| Hybrid Haven Motors Ltd | Wholesale & retail | 2025 |
| Hydecourt Developments Limited | Financial services | 1971 |
| Hydrotech SS Ltd | Construction | 2020 |
| Hyper Eats Ltd | Hospitality | 2024 |
| Hyperchat Limited | Administrative & support | 2021 |
| Hyperevents Ltd | Hospitality | 2025 |
| I &H Trading Ltd | Administrative & support | 2012 |
| I 52 Co Limited | Wholesale & retail | 2005 |
| I DO Handyman Ltd | Construction | 2025 |
| I Hadad Limited | Health & social care | 2015 |
| I K Restaurant & Pizza Limited | Hospitality | 2024 |
| I Swiss Technology Ltd | Manufacturing | 2023 |
| I.R Barsoum & Company Limited | Real estate | 2016 |
| IBC Equipment & Supplies Ltd | Wholesale & retail | 2009 |
| IBN Property Investments Ltd | Real estate | 2022 |
| IBZ Medical Recruitment Limited | Health & social care | 2025 |
| IC Performance Limited | Other services | 2023 |
| Ice Queeen Ltd | Wholesale & retail | 2017 |
| Icon Readymix Ltd | Manufacturing | 2017 |
| ICT Agents Limited | Professional & scientific | 2014 |
| Idam Ltd | Professional & scientific | 2019 |
| Ideal Fitted Bedrooms Ltd | Construction | 2019 |
| Ideal Fitted Group Ltd | Construction | 2026 |
| Ideal Fitted Joinery Ltd | Construction | 2026 |
| Ideal Home Building Services Limited | Construction | 2015 |
| Ideal Home Services Ltd | Construction | 2015 |
| Ideaz Limited | Wholesale & retail | 2017 |
| Idle Capital Ltd | Financial services | 2024 |
| Idle Inc. Ltd. | Professional & scientific | 2017 |
| IDS International Ltd | Wholesale & retail | 2023 |
| IED UK Trading Ltd | Other services | 2015 |
| Iepci UK Ltd | Construction | 2026 |
| Ifit Motors Limited | Wholesale & retail | 2017 |
| IFM DGC Limited | Wholesale & retail | 2026 |
| Ifood UK 1 Ltd | Wholesale & retail | 2023 |
| Iftah CIC | Information & communication | 2019 |
| IG Foods UK Limited | Hospitality | 2019 |
| IGK Supply Ltd | Wholesale & retail | 2018 |
| IGS Holding Limited | Manufacturing | 2009 |
| Iiwii Properties Ltd | Households | 2025 |
| Ikwen Consulting Ltd | Information & communication | 2026 |
| Ilda DI Vico Couture Millinery Limited | Wholesale & retail | 2009 |
| Iliegal Limited | Wholesale & retail | 2020 |
| Ille DE Coco Limited | Wholesale & retail | 2014 |
| Illi Style Limited | Construction | 2026 |
| Illyrian Performance Ltd | Wholesale & retail | 2025 |
| Imco (3496) Limited | Extraterritorial | 1996 |
| IMF Transportation Ltd | Transport & logistics | 2022 |
| Immago Ltd | Administrative & support | 2021 |
| Immana Ltd | Health & social care | 2021 |
| Imobile Ltd | Wholesale & retail | 2026 |
| Imperial Business (London) Ltd | Real estate | 2018 |
| Imperial Crest Estates Ltd | Real estate | 2025 |
| Imperial Group MAX Ltd | Wholesale & retail | 2024 |
| Imperial Refurbishment Ltd | Construction | 2020 |
| Imperium Cognitio Limited | Real estate | 2019 |
| Imperium Salon Ltd | Health & social care | 2018 |
| Imperium Tech UK Ltd | Information & communication | 2018 |
| Impressia Construction Ltd | Construction | 2024 |
| Improvemen Ltd | Administrative & support | 2019 |
| Inbeyond Ltd | Wholesale & retail | 2023 |
| Inci 2 Limited | Wholesale & retail | 2016 |
| Indall Ltd | Wholesale & retail | 2025 |
| Indian Food Wala Limited | Hospitality | 2017 |
| Indigenius Ltd. | Real estate | 2016 |
| Indo Gulf Visions Limited | Information & communication | 2013 |
| Indrasri Ltd | Real estate | 2022 |
| Infi Visions Ltd | Information & communication | 2021 |