| Global Security Management Ltd | Administrative & support | 2021 |
| Glow & Go Hair Extension Co Ltd | Other services | 2025 |
| GNS Aero Engineering Ltd | Manufacturing | 2024 |
| Go Big Events Ltd | Arts & recreation | 2024 |
| Gone Solar Limited | Construction | 2023 |
| Gorilla Aviators Ltd | Manufacturing | 2025 |
| Grace Community Church Porthcawl | Other services | 2011 |
| Grace's Gift Limited | Other services | 2016 |
| Graig Wood CIC | Agriculture & fishing | 2024 |
| Grandspan Limited | Arts & recreation | 1999 |
| Gravells Aerospace Limited | Manufacturing | 2014 |
| Greg Hill Architects Limited | Professional & scientific | 2012 |
| Griffins (Porthcawl) Limited | Hospitality | 2003 |
| Griffins Holding Co Limited | Hospitality | 2023 |
| Griffins Porthcawl (Holdings) Limited | Financial services | 2023 |
| Griffins Porthcawl Property Development Limited | Real estate | 2019 |
| Gronow Residences Limited | Real estate | 2018 |
| Grounded Training Ltd | Education | 2023 |
| Grow and Grind Limited | Hospitality | 2021 |
| Grwp Eiddo Limited | Real estate | 2024 |
| GSH Air Conditioning Ltd | Construction | 2025 |
| GW Designtech Limited | Manufacturing | 2016 |
| Gwalia Grips Ltd | Information & communication | 2025 |
| H R Battrick Properties Limited | Real estate | 2014 |
| Haja Consulting Ltd | Professional & scientific | 2026 |
| Haja Sports Ltd | Manufacturing | 2025 |
| Harbwr Deli Ltd | Hospitality | 2025 |
| Harris Property Development Limited | Real estate | 1994 |
| Hassan Engineering Limited | Manufacturing | 2023 |
| Hawkins CPC Limited | Construction | 2018 |
| HD Porthcawl Ltd | Real estate | 2026 |
| Healthy High Club Limited | Arts & recreation | 2023 |
| Heathridge Aerospace Ltd | Manufacturing | 2014 |
| Hemlock Trading Limited | Wholesale & retail | 2024 |
| Heritage Hotel Porthcawl Limited | Hospitality | 2018 |
| Highfield Court (Porthcawl) Management Company Limited | Real estate | 1986 |
| Hikitalo Ltd | Other services | 2024 |
| HK Aerospace Limited | Transport & logistics | 2007 |
| Hodge Management Services Ltd | Professional & scientific | 2022 |
| HPE Holdings Ltd | Extraterritorial | 2024 |
| HR Systems Consult Ltd | Information & communication | 2021 |
| Hugbcnext Ltd | Professional & scientific | 2022 |
| Hughes Civil & Surveying Ltd | Construction | 2026 |
| Hughes Engineering and Surveying Solutions Ltd | Construction | 2025 |
| HUW Thomas Ltd | Professional & scientific | 2012 |
| Hwinter Property Lets Limited | Real estate | 2018 |
| Hwyl.Health Limited | Arts & recreation | 2026 |
| Hydroscan Services Ltd | Transport & logistics | 2025 |
| Hydrover Turbine Services Limited | Manufacturing | 2016 |
| Hydrover Turbine Servicing Limited | Real estate | 2023 |
| I M Power Group Limited | Financial services | 2013 |
| I M Power Management Services Limited | Construction | 2021 |
| I-R Management Ltd | Real estate | 2024 |
| Idropped IT Ltd. | Other services | 2015 |
| Iechyd Bella Limited | Health & social care | 2025 |
| Ieuan Harris Building Contractors Limited | Construction | 2026 |
| Ihpp Holdings Ltd | Information & communication | 2022 |
| IKT Civil Engineering Services Limited | Transport & logistics | 2010 |
| Illicit Limited | Arts & recreation | 2003 |
| Inclusability CIC | Education | 2020 |
| Inotek Limited | Construction | 2020 |
| INVIGOR8@THEPORTWAY Limited | Arts & recreation | 2026 |
| Isabella's Properties Limited | Real estate | 2021 |
| It's My Shout Community Interest Company | Information & communication | 2007 |
| Itsjester Ltd | Wholesale & retail | 2014 |
| J B GAS Ltd | Construction | 2019 |
| J D Composites Limited | Transport & logistics | 2003 |
| J P Tattooist Limited | Other services | 2022 |
| J to Go Transport Ltd | Transport & logistics | 2016 |
| J&G Enterprise Limited | Professional & scientific | 2002 |
| J&R Aerospace Limited | Manufacturing | 2016 |
| J&R Aerostructures Limited | Manufacturing | 2023 |
| J&R Aircraft Engineering Limited | Manufacturing | 2019 |
| J&R Commercials Ltd | Wholesale & retail | 2024 |
| J&V Solutions Limited | Manufacturing | 2016 |
| J&Y Aerotech Limited | Manufacturing | 2017 |
| James Lott the Building Company Ltd | Construction | 2024 |
| Jancer Development Company Limited | Real estate | 1973 |
| Jaymojourneyman Ltd | Hospitality | 2023 |
| JC Aerotech Limited | Transport & logistics | 2012 |
| Jcaviation Ltd | Manufacturing | 2022 |
| JD Aviation Engineering Limited | Transport & logistics | 2007 |
| Jenipher's Coffi Ltd | Wholesale & retail | 2021 |
| Jenoat Limited | Other services | 1980 |
| Jessylettings Ltd | Real estate | 2025 |
| Jetranch Limited | Real estate | 2004 |
| Jets Engineering Ltd | Manufacturing | 2022 |
| Jetx Engineering Limited | Manufacturing | 2017 |
| Jinked Tattoo Club Ltd | Wholesale & retail | 2026 |
| JJ & VJ Reed Holdings Limited | Financial services | 2025 |
| JJ & VJ Reed Ltd | Health & social care | 2014 |
| JJH Composite's Ltd | Manufacturing | 2025 |
| JJH Maintenance Ltd | Professional & scientific | 2024 |
| JJP Suppliers Ltd | Construction | 2025 |
| JLG Associates Limited | Professional & scientific | 2021 |
| JLJ Eyetech Limited | Health & social care | 2017 |
| JLW Composites Limited | Manufacturing | 2016 |
| Jmjc Properties Limited | Real estate | 2020 |
| John P Thomas & Co Limited | Administrative & support | 2017 |
| JP Design Labs Limited | Information & communication | 2026 |