| Frame That Photo Limited | Professional & scientific | 1998 |
| Freshwater Bay Coasteering Ltd | Arts & recreation | 2021 |
| Fried Air Limited | Manufacturing | 2024 |
| Frog Delivery Ltd | Transport & logistics | 2026 |
| Fruit Basket Limited | Administrative & support | 2003 |
| G & J Receivables Management Services Ltd | Professional & scientific | 2016 |
| G a Star Builders Limited | Construction | 2025 |
| G&G Aerial Yoga Limited | Arts & recreation | 2022 |
| Gallant Capital Limited | Financial services | 2025 |
| Gallantgreen Developments Limited | Financial services | 2025 |
| Gary Clarke Sound Limited | Information & communication | 2013 |
| Gavin Pomeroy Consulting Ltd | Professional & scientific | 2019 |
| GE Public Relations Ltd | Information & communication | 2015 |
| George Jenkins Holdings Ltd | Financial services | 2018 |
| George Jenkins Transport Limited | Transport & logistics | 1987 |
| Georgina Grose Limited | Manufacturing | 2014 |
| Gf-Tronics Ltd | Information & communication | 2019 |
| Ginger Circus Ltd | Arts & recreation | 2018 |
| Golden Valley Hobbies Limited | Manufacturing | 2004 |
| Good Knight Pest Control Limited | Administrative & support | 2022 |
| Gordon Close 1971 Limited | Extraterritorial | 2015 |
| Gosport Choice Limited | Information & communication | 2005 |
| Graft Studios IOW C.I.C. | Education | 2026 |
| Graham Burns Yoga Limited | Education | 2021 |
| GRC Risk Services Ltd | Professional & scientific | 2014 |
| Green Lane (Sandown) Management Limited | Real estate | 2006 |
| Green Mile Charging Co Ltd | Construction | 2019 |
| Greenfield (IOW) Management Company Limited | Households | 2015 |
| Griffin-Gore Medics Ltd | Health & social care | 2018 |
| GSF Training Limited | Other services | 2004 |
| GUY Rowland Broadcast Limited | Information & communication | 2003 |
| Hampshire House Management Company Limited | Households | 1996 |
| Hamtons Limited | Real estate | 2000 |
| Hannan Developments Ltd | Construction | 2002 |
| Hardship&Relief Ltd | Health & social care | 2025 |
| Harrison Lettings (South) Limited | Real estate | 2023 |
| Harrison Plumbing & Heating Solutions Limited | Construction | 2022 |
| Hartleys Countrydogs Ltd | Wholesale & retail | 2025 |
| Hartsash Geological Ltd | Construction | 2020 |
| Haulage Track Limited | Transport & logistics | 2025 |
| Headington Orchard Ltd | Real estate | 2023 |
| Headstrong Education Limited | Education | 2019 |
| Healing Health Joy Collective Limited | Health & social care | 2023 |
| Heartspace Yoga Events Ltd | Other services | 2023 |
| Heat-Tec IW Ltd | Construction | 2023 |
| Hellenic Innovators Ltd | Professional & scientific | 2021 |
| Henka Medical Communications Ltd | Professional & scientific | 2025 |
| High Speed Craft Limited | Professional & scientific | 1990 |
| Hillslea Court Management Company Limited | Real estate | 1989 |
| HJD Group Ltd | Information & communication | 2025 |
| HK Heating and Plumbing Limited | Construction | 2014 |
| HMSTM1 Ltd | Hospitality | 2026 |
| Holmes and Family Ltd | Other services | 2015 |
| Hometech (IOW) Limited | Construction | 2007 |
| Honeycroft Homes Ltd | Real estate | 2016 |
| Honeycroft Properties Ltd | Real estate | 2019 |
| Houze Enterprise Limited | Real estate | 2022 |
| Howard Developments IW Ltd | Construction | 2023 |
| HRD Auction Rooms Ltd | Administrative & support | 2017 |
| HT Brickwork Limited | Construction | 2013 |
| Hwyl Studio Ltd | Education | 2023 |
| Hyace Limited | Information & communication | 2004 |
| Hybrid Machine Intelligence Ltd | Extraterritorial | 2025 |
| Hybrid MI Limited | Manufacturing | 2023 |
| Hydromar Ltd | Manufacturing | 2002 |
| ICR Group I.O.W Ltd | Financial services | 2022 |
| ICR Properties (South) Ltd | Real estate | 2025 |
| ICR Systems Ltd | Wholesale & retail | 2017 |
| Icrtouch (IOW) Ltd | Information & communication | 2011 |
| IMC Sandown Ltd | Hospitality | 2020 |
| Inachis Consulting Limited | Professional & scientific | 2004 |
| Inbodhi Trainings Ltd | Education | 2020 |
| Infernonetwork Ltd | Professional & scientific | 2026 |
| Inspiring Solutions Limited | Professional & scientific | 2002 |
| Integrated Yoga and Mindfulness Ltd | Administrative & support | 2015 |
| Invest IW Ltd | Extraterritorial | 2014 |
| Invictus Lodging Services Limited | Hospitality | 2019 |
| IOW Badgers Ltd | Other services | 2024 |
| IOW Construction Training Group Ltd | Professional & scientific | 2018 |
| IOW Homes Ltd | Real estate | 2024 |
| IOW Hospitality Group Ltd | Hospitality | 2023 |
| Iowgas Ltd | Construction | 2019 |
| Iowsolar Systems Ltd | Construction | 2023 |
| Island Aerospace Ltd | Other services | 2017 |
| Island and Solent Psychological Therapies Limited | Health & social care | 2006 |
| Island Ceiling Systems Limited | Construction | 2001 |
| Island Girl (IOW) Ltd | Wholesale & retail | 2024 |
| Island Identity CIC | Professional & scientific | 2020 |
| Island Inboards Limited | Manufacturing | 2001 |
| Island Nail & Spa Ltd | Other services | 2023 |
| Island People Ltd | Extraterritorial | 2021 |
| Island Powder Coating & Electroplating Limited | Manufacturing | 2011 |
| Island Powder Coating Ltd | Manufacturing | 2024 |
| Island Power Tools and Hire Centre Limited | Manufacturing | 1995 |
| Island Sports Alliance Community Interest Company | Education | 2024 |
| Island Sports and Performance Ltd | Wholesale & retail | 2025 |
| Island Technologies Ltd | Construction | 2024 |
| Island Van Services Limited | Transport & logistics | 2017 |
| Island Windows & the Plastics Depot Ltd | Construction | 2021 |
| Islandwide Carpets Limited | Wholesale & retail | 2001 |