| Hook Hampshire Limited | Hospitality | 2013 |
| Hook Motor Services Limited | Wholesale & retail | 2022 |
| Hook Pet Supplies Ltd | Wholesale & retail | 2015 |
| Hook Service Station Ltd | Wholesale & retail | 2019 |
| Hook Town Barbers Limited | Other services | 2025 |
| Hook Village Halls Charitable Association | Real estate | 2007 |
| Hopkinsons Garage Limited | Wholesale & retail | 2003 |
| Horizon Boiler Hire Ltd | Administrative & support | 2022 |
| Horizon Satellite, Aerial & Home Entertainment Limited | Administrative & support | 2003 |
| Horizon Sound and Vision Limited | Information & communication | 2019 |
| Horler&Co Ltd | Professional & scientific | 2024 |
| Horses for Courses Limited | Agriculture & fishing | 2000 |
| Horti Mech Ltd | Wholesale & retail | 2026 |
| Horton Media Services Ltd | Professional & scientific | 2022 |
| Hortus Centrum Ltd | Financial services | 2020 |
| Hortus Loci Landscapes Ltd | Agriculture & fishing | 2018 |
| Hortus Mondus Ltd | Wholesale & retail | 2021 |
| Hosta Investments Limited | Real estate | 2024 |
| Hotbox Events Ltd | Other services | 2022 |
| Hotbox Studios Limited | Information & communication | 2003 |
| House of Hampshire Limited | Other services | 2024 |
| House of Hook Limited | Manufacturing | 2025 |
| Howard Taylor Holdings Limited | Financial services | 2021 |
| Howard Taylor Investments Limited | Financial services | 2006 |
| Howlands Sales & Lettings Ltd | Real estate | 2013 |
| HQ Property Services Limited | Administrative & support | 2022 |
| Humble House Holdings Ltd | Real estate | 2022 |
| Huttons Green Management Limited | Households | 2005 |
| HW Garage Ltd | Wholesale & retail | 2019 |
| Hyde Crook Nursing Home Limited | Hospitality | 2002 |
| Hydroflex-Eu Limited | Extraterritorial | 2016 |
| HZ One Limited | Professional & scientific | 2026 |
| I Magician Live Limited | Arts & recreation | 2018 |
| I Want That Sign.Com Ltd | Wholesale & retail | 2009 |
| I'M NO Expert Limited | Extraterritorial | 2025 |
| I4 Exhibitions Limited | Administrative & support | 2009 |
| IAN Welch Grab Services Limited | Water & waste | 2014 |
| Icon UK Limited | Information & communication | 2012 |
| Iconcept Limited | Information & communication | 2004 |
| ID Holdings Limited | Professional & scientific | 2016 |
| Ignition BD Limited | Professional & scientific | 2025 |
| Illuminate Legal Limited | Professional & scientific | 2016 |
| IM Valeting Ltd | Wholesale & retail | 2025 |
| IMPACT4AG Limited | Professional & scientific | 2023 |
| Inception Planning Limited | Construction | 2008 |
| Incubinc Limited | Administrative & support | 2018 |
| Independent Healthcare Consultancy Limited | Extraterritorial | 1997 |
| Independent Motor Auctions (2006) Limited | Wholesale & retail | 2006 |
| Indexsecond Limited | Information & communication | 2021 |
| Indoor Organics Ltd | Other services | 2017 |
| Industry Insights Group Limited | Professional & scientific | 2022 |
| Infinity Human Capital Ltd. | Administrative & support | 2017 |
| Innjoy Limited | Hospitality | 2003 |
| Inodiham CIC | Other services | 2015 |
| Insight Delivered Limited | Information & communication | 2015 |
| Insight Wealth Preservation Ltd | Professional & scientific | 2016 |
| Inspiralytics Ltd | Administrative & support | 2017 |
| Inspirations Hair and Beauty Limited | Other services | 2002 |
| Inspired Insight Limited | Information & communication | 2000 |
| Inspiring Directions Ltd | Administrative & support | 2018 |
| Instant CPD Limited | Information & communication | 2011 |
| Intact Construction Ltd | Construction | 2026 |
| Integrated Fire and Security Systems Ltd | Administrative & support | 2021 |
| Integrated Management Control Limited | Real estate | 1995 |
| Integrated Marketing Contact Limited | Real estate | 1995 |
| Intelligent Billing Technologies Limited | Extraterritorial | 2019 |
| Intelligent Information Management Ltd | Administrative & support | 2003 |
| Intentional Drinks Ltd | Wholesale & retail | 2026 |
| Intentional Industries Limited | Information & communication | 2023 |
| Interconnect Group Limited | Professional & scientific | 2026 |
| INVEST2MENTS Ltd | Other services | 2025 |
| Inyati Property Investments Ltd | Real estate | 2024 |
| Ions-Net Limited | Energy | 2022 |
| IP Data Consulting Limited | Professional & scientific | 2015 |
| Ipcoreservices Limited | Information & communication | 2012 |
| IQ Financial Submissions Limited | Professional & scientific | 2026 |
| Isaac & Laila Limited | Real estate | 2020 |
| Itthings Limited | Manufacturing | 2017 |
| Ivagu Ltd | Construction | 2017 |
| IW Media Force Limited | Wholesale & retail | 2018 |
| IZ Tech Solutions Ltd | Wholesale & retail | 2025 |
| J and a Markings Limited | Construction | 2014 |
| J Hunter Foods Ltd | Professional & scientific | 2009 |
| J S Agriculture Limited | Administrative & support | 2002 |
| J&C MCD Consulting Limited | Information & communication | 2013 |
| J&S Vehicle Services Limited | Wholesale & retail | 2025 |
| JA Hotels Limited | Hospitality | 2025 |
| Jack Bowie Racing Ltd | Professional & scientific | 2021 |
| Jackal Tree Trading Ltd | Construction | 2026 |
| Jackson Maunders Limited | Real estate | 2004 |
| Jaho Electronics Ltd | Manufacturing | 2014 |
| Jakal Properties Limited | Professional & scientific | 1998 |
| Jake Hammerton Limited | Construction | 2025 |
| James Ellis Consultancy Ltd | Financial services | 2016 |
| James Farm Day Nursery Limited | Education | 2013 |
| James FRY Developments Ltd | Construction | 2022 |
| James FRY Properties Ltd | Construction | 2022 |
| Jamie Butler Coaching Limited | Professional & scientific | 2020 |
| JAN Etherington Associates Limited | Administrative & support | 2004 |
| Janet Standing Consultancy Ltd | Administrative & support | 2025 |