| Hybrid International Limited | Administrative & support | 2016 |
| Hybrid Technology Ltd | Information & communication | 2015 |
| Hybriditec Ltd | Information & communication | 2018 |
| Hydeng Marine Services Limited | Transport & logistics | 2024 |
| Hyderabadi Paradise Ltd | Hospitality | 2023 |
| Hydrafact Green Solutions Limited | Professional & scientific | 2021 |
| Hydrafact Investment Limited | Financial services | 2021 |
| Hydrafact Limited | Professional & scientific | 2005 |
| Hydro - Dynamics Limited | Administrative & support | 2009 |
| Hydro JET Services Ltd | Administrative & support | 2019 |
| Hydro Market LP | | 2017 |
| Hydrogen Scotland Ltd | Other services | 2004 |
| Hydrogen Universe Ltd | Professional & scientific | 2018 |
| Hydrogen Vehicle Systems Ltd | Manufacturing | 2017 |
| Hydrogenone Capital Growth (Carried Interest) (GP) Limited | Financial services | 2020 |
| Hydrogenone Capital Growth (Carried Interest) LP | | 2021 |
| Hydrographic Data Services Ltd. | Information & communication | 2018 |
| Hydrographic Offshore Processing Experts Ltd | Information & communication | 2025 |
| Hydronic Heating Edinburgh Ltd | Construction | 2024 |
| Hydroproject Corporation LP | | 2013 |
| Hydrosense Limited | Administrative & support | 2000 |
| Hydrostroyinvest LP | | 2013 |
| Hyegazian Limited | Information & communication | 2007 |
| Hygge Healing Ltd | Health & social care | 2022 |
| Hylomorph Solutions Limited | Information & communication | 2019 |
| Hyman Offshore Trading LP | | 2015 |
| Hype Digital Ltd | Information & communication | 2025 |
| Hyper Resilience Limited | Information & communication | 2025 |
| Hyper Sanctum LP | | 2015 |
| HYPER9 Ltd | Information & communication | 2021 |
| Hyperion Tech Limited | Information & communication | 2021 |
| Hypernormalisation Admin Ltd | Arts & recreation | 2023 |
| Hypernumbers Limited | Administrative & support | 2007 |
| Hyperpress LP | | 2019 |
| Hyperpulse Market Limited | Wholesale & retail | 2025 |
| Hypersonic Entertainment Limited | Professional & scientific | 2025 |
| Hypertrade Group Limited | Wholesale & retail | 2024 |
| Hypevia Ltd | Administrative & support | 2024 |
| Hypha I (Scotland) Ltd | Financial services | 2024 |
| Hypha I FP LP | | 2024 |
| Hypha Research Limited | Information & communication | 2004 |
| Hyskeir Holdings Limited | Financial services | 2025 |
| Hyskeir Limited | Professional & scientific | 1988 |
| Hysteresis Media Ltd | Information & communication | 2017 |
| HZA Management Ltd | Extraterritorial | 2012 |
| HZK II Ltd | Wholesale & retail | 2023 |
| HZP Ltd | Wholesale & retail | 2019 |
| I & a Brothers Ltd | Wholesale & retail | 2012 |
| I & N Records Limited | Wholesale & retail | 1979 |
| I & R Murdoch & Co | Administrative & support | 2022 |
| I ACT Contracting Limited | Construction | 2019 |
| I Box Foods Limited | Hospitality | 2017 |
| I DO Bridal & Event Hair Ltd | Other services | 2021 |
| I Go to Therapy Ltd | Wholesale & retail | 2020 |
| I J Mcleish Ltd | Wholesale & retail | 2012 |
| I L H Services Limited | Mining & quarrying | 2019 |
| I Love Cafes Ltd | Hospitality | 2012 |
| I LUV EMS Ltd | Arts & recreation | 2025 |
| I LUV Ltd | Wholesale & retail | 2010 |
| I SE India Limited | Wholesale & retail | 2023 |
| I&R Taxi Ltd | Transport & logistics | 2025 |
| I&S Designs Ltd | Professional & scientific | 2019 |
| I'Mperfect Foods | Hospitality | 2016 |
| I-Confidential Corporate Trustee Limited | Financial services | 2023 |
| I-Confidential Limited | Information & communication | 2010 |
| I-Deal EU LP | | 2016 |
| I-Dealseed Limited | Wholesale & retail | 2014 |
| I-Max Technology L.P. | | 2012 |
| I-Mist Scotland Ltd | Manufacturing | 2018 |
| I-Nquire Technology Ltd | Information & communication | 2011 |
| I-Smart Corporation | | 2009 |
| I-Spot Limited | Professional & scientific | 2008 |
| I-Tech Global L.P. | | 2011 |
| I-Tech Solutions Worldwide L.P. | | 2010 |
| I-Technique Consulting Ltd | Information & communication | 2025 |
| I-Trade Worldwide L.P. | | 2011 |
| I.A.R.G Ltd | Administrative & support | 2012 |
| I.B.D. Partners LP | | 2015 |
| I.Ideo Limited | Administrative & support | 2017 |
| I.K.J. Alliance L.P. | | 2009 |
| I.L.T. Integrated Laser Technologies | | 1992 |
| I.R.G. International L.P. | | 2008 |
| I.R.O Painting and Decorating Ltd | Construction | 2023 |
| I.S. Convenience Store Ltd | Wholesale & retail | 2024 |
| I.S.A.K. Union Enterprises L.P. | | 2008 |
| I.T. Cyclone LP | | 2018 |
| I.T. Discounts Limited | Information & communication | 2008 |
| I10.AI Ltd | Information & communication | 2025 |
| I3ACK Ltd | Transport & logistics | 2025 |
| I4 Product Design Limited | Professional & scientific | 2003 |
| IA Edin Ltd | Professional & scientific | 2024 |
| IA Gordon Management Ltd | Extraterritorial | 2012 |
| IAD Marketing Ltd | Professional & scientific | 2023 |
| IAE1 GP LLP | | 2021 |
| IAE1 LP | | 2021 |
| IAE3 Davy GP LLP | | 2024 |
| IAE3 Davy LP | | 2024 |
| IAG Marketing Ltd | Financial services | 2016 |
| IAG92 Ltd | Transport & logistics | 2026 |
| Iain Adams Limited | Health & social care | 2024 |