| Hybrid Management Limited | Real estate | 2017 |
| Hybrid Office Furniture Ltd. | Wholesale & retail | 2011 |
| Hybrid Shooters Ltd | Professional & scientific | 2018 |
| Hybrid Traders Ltd | Wholesale & retail | 2021 |
| HYC Home Limited | Real estate | 2023 |
| Hyca Musical Limited | Arts & recreation | 2023 |
| Hyconems Limited | Manufacturing | 2024 |
| Hydair Limited | Administrative & support | 2016 |
| Hyde Eleven Ltd | Real estate | 2025 |
| Hydebids Ltd | Professional & scientific | 2023 |
| Hyderabad Deccan Community Association UK CIC | Education | 2022 |
| Hydra Heating and Ventilation Limited | | 1986 |
| Hydra Naturals Ltd | Manufacturing | 2022 |
| Hydraforce Hydraulics Limited | Manufacturing | 1988 |
| Hydrapower Dynamics Limited | Manufacturing | 1983 |
| Hydro Clear Group Limited | Administrative & support | 2021 |
| Hydro Design Company Ltd | Wholesale & retail | 2016 |
| Hydro Energy WM Ltd | Administrative & support | 2025 |
| Hydro Project Engineering Limited | Manufacturing | 1995 |
| Hydro Zone (Midlands) Limited | Wholesale & retail | 2014 |
| Hydro-Link Consulting Ltd | Professional & scientific | 2026 |
| Hydrodesk Ltd | Information & communication | 2012 |
| Hydrogel Healthcare Limited | Manufacturing | 2012 |
| Hydroguard Solutions Ltd | Administrative & support | 2026 |
| Hydroinformatics Solutions Ltd | Extraterritorial | 2020 |
| Hydroland Consulting Engineers Ltd | Construction | 2012 |
| Hydronomy Ltd | Agriculture & fishing | 2020 |
| Hydrous Environmental Construction Services Ltd | Construction | 2024 |
| Hydrus Energy Ltd | Construction | 2023 |
| Hyfi Have YOU Fried IT? Limited | Hospitality | 2025 |
| Hyfi Ladypool Road Ltd | Hospitality | 2026 |
| Hyfinity Limited | Information & communication | 2001 |
| Hyfore Workholding Limited | Manufacturing | 2001 |
| Hygen Heating Ltd | Construction | 2024 |
| Hygenisys Environmental Health Ltd | Administrative & support | 2012 |
| Hygge Care Ltd | Health & social care | 2015 |
| Hygge Play Cafe Ltd | Education | 2025 |
| Hygia Living Ltd | Real estate | 2026 |
| Hygia Ltd | Health & social care | 2021 |
| Hygiene Group Limited | Administrative & support | 1985 |
| Hygiene Stores (UK) Limited | Wholesale & retail | 2001 |
| Hygiene UK Holdings Ltd | Financial services | 2019 |
| HYL Catering Limited | Hospitality | 2025 |
| Hyland Support Services Ltd | Health & social care | 2023 |
| Hylionlink Limited | Information & communication | 2026 |
| Hylorone Ltd | Other services | 2024 |
| Hylton & Co Services Ltd | Construction | 2024 |
| Hylton Management Limited | Other services | 2005 |
| Hylts Academy Limited | Arts & recreation | 2024 |
| HYM Logistics Limited | Transport & logistics | 2025 |
| Hymek D7029 (DTG) Limited | Manufacturing | 2005 |
| Hypa Aluminium Extrusions Ltd | Manufacturing | 2013 |
| Hypa Automotive Ltd | Manufacturing | 2017 |
| Hype&Co Ltd | Wholesale & retail | 2026 |
| Hyped Properties Ltd | Real estate | 2021 |
| Hyped Properties Management Ltd | Real estate | 2025 |
| Hypemotion Arena Ltd | Arts & recreation | 2025 |
| Hyper E-Commerce Ltd | Wholesale & retail | 2026 |
| Hyper Ecom Business Ltd | Wholesale & retail | 2026 |
| Hyper Mart Ltd | Wholesale & retail | 2023 |
| Hyper Modern Ltd | Professional & scientific | 2018 |
| Hyper Secure Services Ltd | Information & communication | 2018 |
| Hyper Soft Studio Ltd | Information & communication | 2025 |
| Hyperbole Limited | Information & communication | 2009 |
| Hypergenesis Ltd | Wholesale & retail | 2022 |
| Hyperheaven Limited | Wholesale & retail | 2023 |
| Hyperian Law Limited | Professional & scientific | 2017 |
| Hyperion Corporation Ltd | Real estate | 2018 |
| Hyperion Group Ltd | Information & communication | 2020 |
| Hypermarket Ltd | Wholesale & retail | 2020 |
| Hypernest Ltd | Wholesale & retail | 2024 |
| Hyperscale Limited | Extraterritorial | 2016 |
| Hyperscale Music Limited | Extraterritorial | 2016 |
| Hypersys Ltd | Wholesale & retail | 2025 |
| Hyphadendrite Myco Ltd | Professional & scientific | 2025 |
| Hypromag Ltd | Professional & scientific | 2018 |
| Hythe and Southampton Ferry Company Limited | Transport & logistics | 2017 |
| Hyve Central LLP | | 2019 |
| HZ Bargainz Ltd | Wholesale & retail | 2018 |
| HZ Consulting Ltd | Professional & scientific | 2022 |
| HZ Ecom Ltd | Wholesale & retail | 2026 |
| HZ Homes Ltd | Real estate | 2020 |
| HZ Management Ltd | Real estate | 2018 |
| HZ Solutions Ltd | Professional & scientific | 2023 |
| HZ Solutionz Ltd | Administrative & support | 2021 |
| HZ Sonic Ltd | Wholesale & retail | 2009 |
| HZB Management Limited | Real estate | 2023 |
| HZG Trading Ltd | Wholesale & retail | 2026 |
| Hzmm Limited | Professional & scientific | 2015 |
| Hébergement D'Élite Ltd | Real estate | 2025 |
| H’S MOT Ltd | Wholesale & retail | 2023 |
| I & a Birmingham Ltd | Hospitality | 2025 |
| I & a Cars Limited | Wholesale & retail | 2018 |
| I & a Holdings West Midlands Ltd | Financial services | 2021 |
| I & F Lettings Limited | Real estate | 2025 |
| I & I Builders Ltd | Construction | 2024 |
| I & J Williams Ltd | Health & social care | 2012 |
| I & M Global Services Ltd | Hospitality | 2014 |
| I & M Warner Properties Limited | Extraterritorial | 2001 |
| I & S Professional Builders Limited | Construction | 2025 |