| Hesketh Racing Limited | Extraterritorial | 2011 |
| Hexagon Plumbing and Heating Ltd | Construction | 2021 |
| Heyan Ltd | Other services | 2024 |
| Hg&Hr Ltd | Hospitality | 2019 |
| HGL Dynamics Holding Co Ltd | Financial services | 2023 |
| HGL Dynamics Limited | Manufacturing | 1999 |
| Higgo Limited | Construction | 2012 |
| Higgo Projects Limited | Construction | 2016 |
| High Button Ltd | Water & waste | 2019 |
| High Hanger Developments Ltd | Construction | 2015 |
| Highbrook Capital Consultants Ltd | Professional & scientific | 2023 |
| Highland Sustainability Limited | Professional & scientific | 2023 |
| Hillcrest Food Limited | Wholesale & retail | 2000 |
| Hills & Heights Holdings Limited | Financial services | 2021 |
| Hills & Heights Surrey Limited | Other services | 2021 |
| Hiveplex Ltd | Wholesale & retail | 2021 |
| HJG Consultancy Ltd | Professional & scientific | 2023 |
| HM Structural Engineering Ltd | Professional & scientific | 2021 |
| Hobart Rynda Living Limited | Real estate | 2025 |
| Holders Yard Management Ltd | Households | 2017 |
| Holland House Events Limited | Hospitality | 2017 |
| Hollins Porter Limited | Professional & scientific | 2022 |
| Holloway Hill Sports Association Limited | Arts & recreation | 1996 |
| Holly Piper Tutoring International Limited | Education | 2024 |
| Holly Wolly Properties Limited | Real estate | 2022 |
| Home Farm Court Residents Association Limited | Households | 1993 |
| Home Farm Land (Shillinglee) Limited | Extraterritorial | 2005 |
| Homemaker With Love Ltd | Administrative & support | 2020 |
| Homes 2 Own (Maidenhead) Limited | Real estate | 2015 |
| Horizon Group Realty Limited | Financial services | 2024 |
| Horseshoe Cove UK Limited | Financial services | 2024 |
| Hother Associates LLP | | 2005 |
| Housebox Ltd | Real estate | 2015 |
| Housetolet Limited | Real estate | 2002 |
| Howard Electrical Group Ltd | Construction | 2026 |
| Howard Electrical Solutions Ltd | Construction | 2024 |
| Howat Ltd | Information & communication | 2021 |
| HQ Hospitality Limited | Hospitality | 2005 |
| HR Business Consultants Ltd | Administrative & support | 2011 |
| HRA Architects Ltd | Professional & scientific | 2015 |
| HT Physio Ltd | Health & social care | 2020 |
| Huddie Engineering Limited | Administrative & support | 2015 |
| Hudson Chase Limited | Wholesale & retail | 1999 |
| Huduhealth Ltd | Wholesale & retail | 2020 |
| Huge Design Limited | Administrative & support | 2003 |
| Hughes Waddell Limited | Professional & scientific | 2010 |
| Hume Executive Search Ltd | Administrative & support | 2011 |
| Hunt & Hope Ltd | Professional & scientific | 2016 |
| Hunter Mews Management Ltd | Households | 2017 |
| Hurlands Innovations Limited | Administrative & support | 2012 |
| HURSTFM98 Limited | Real estate | 2013 |
| HURSTFM99 Limited | Real estate | 2021 |
| Hurstfold Investments Limited | Real estate | 1994 |
| Hurtmore Heights Management Company Ltd | Administrative & support | 2016 |
| Hutt Medical Limited | Health & social care | 2017 |
| Hydestile Joinery | | 1998 |
| Hydon Park Management Company Limited | Households | 1998 |
| Hyper Stainguard Ltd | Manufacturing | 2025 |
| I-Start Limited | Professional & scientific | 2014 |
| IAN White Group Ltd | Wholesale & retail | 2007 |
| Idea Parlour Ltd | Professional & scientific | 2005 |
| Ideal Student LET Ltd | Hospitality | 2022 |
| Idtrack Limited | Manufacturing | 2024 |
| Idunn Rejuvenation Retail Limited | Other services | 2024 |
| IE Eventing Ltd | Arts & recreation | 2023 |
| Igas Technology Solutions Limited | Construction | 2001 |
| Igas Technology Trustee Limited | Other services | 2023 |
| Igloo Care Ltd | Construction | 2021 |
| Igloo Developments (South) Ltd | Real estate | 2010 |
| Igloo Developments Cobham Limited | Real estate | 2023 |
| Igloo Developments Pound Lane Limited | Real estate | 2026 |
| Igloo Strategic Land Limited | Real estate | 2026 |
| Iglove Design Limited | Professional & scientific | 2014 |
| Igmtb Ltd | Construction | 2020 |
| Iles (Norbury) Limited | Construction | 2014 |
| Image Building Projects Ltd | Construction | 2025 |
| Imagine Theatre Limited | Arts & recreation | 2005 |
| Imex Projects Limited | Professional & scientific | 2012 |
| Impact Financial Consulting Ltd | Professional & scientific | 2025 |
| Improv Inc Ltd | Professional & scientific | 2023 |
| IN a NUT Shell (Surveyors and Valuers) Ltd | Professional & scientific | 2024 |
| Inchora Limited | Professional & scientific | 2011 |
| Incisiant Limited | Other services | 2020 |
| Incnc Ltd | Public administration | 2024 |
| Indigenous Beauty Limited | Wholesale & retail | 2016 |
| Individual Aesthetic Ltd | Wholesale & retail | 2015 |
| Infinite Ammo Limited | Information & communication | 2010 |
| Infinity MED Groups Limited | Health & social care | 2025 |
| Information Technologies and Systems Ltd | Wholesale & retail | 2015 |
| INK on Everything Ltd | Professional & scientific | 2016 |
| Inkerman Hire Services Ltd | Transport & logistics | 2003 |
| Inner Space Consulting Limited | Professional & scientific | 2013 |
| Innoplus Technologies Ltd | Wholesale & retail | 2025 |
| Innovation Place Management Limited | Real estate | 2015 |
| Innovation Visual Ltd. | Information & communication | 2005 |
| Insight to Thrive Limited | Professional & scientific | 2013 |
| INSIGHT2IMPLEMENT Limited | Professional & scientific | 2010 |
| Inspired Earth Design Ltd | Professional & scientific | 2021 |
| Insticator UK Limited | Information & communication | 2021 |
| Insurian Limited | Administrative & support | 2020 |