| H P G Commercials Ltd | Wholesale & retail | 2026 |
| H P R Solutions Limited | Manufacturing | 2000 |
| H&H Food Group Ltd | Hospitality | 2026 |
| H&R Property Solutions and Management Ltd | Real estate | 2026 |
| H. Deere Limited | Other services | 1977 |
| H20 Building Services Limited | Construction | 2016 |
| H2O BS Holdings Limited | Financial services | 2021 |
| H2O Properties South Wales Limited | Households | 2025 |
| Hafan Clyd Ltd | Real estate | 2025 |
| Hafan Medical Limited | Health & social care | 2025 |
| Hafod Ganol Farm Limited | Hospitality | 2023 |
| Hailianshangmao Ltd | Wholesale & retail | 2026 |
| Haisnda Int'L Trading Limited | Professional & scientific | 2014 |
| HAK Hire Services Ltd | Administrative & support | 2020 |
| Halicer Ltd | Wholesale & retail | 2025 |
| Halstaad Commercial Limited | Construction | 2022 |
| Hand Property Ltd | Real estate | 2022 |
| Hannok Ltd | Wholesale & retail | 2026 |
| Happy Boots CIC | Administrative & support | 2022 |
| Harding's Distribution Ltd | Transport & logistics | 2025 |
| Hardwidge Consulting Limited | Information & communication | 2010 |
| Harmony Whole Person Healing Ltd | Professional & scientific | 2022 |
| Harp International Holdings Limited | Professional & scientific | 2008 |
| Harp Overseas Holdings Limited | Extraterritorial | 1996 |
| Harris Membrane (UK) Solution Technology Limited | Wholesale & retail | 2026 |
| Harrison Building & Property Services Limited | Construction | 2017 |
| Harry's Plaice Limited | Hospitality | 2016 |
| HAS Magnetics Consulting Ltd | Professional & scientific | 2019 |
| Hasslab Instrument Limited | Professional & scientific | 2015 |
| Haul Installations CYF | Construction | 2026 |
| Haus of C & G Ltd | Hospitality | 2026 |
| Have FUN GET Fit CIC | Arts & recreation | 2022 |
| Haven Letting Ltd | Real estate | 2020 |
| Hawa Barbers Pontypridd Ltd | Other services | 2025 |
| Hawkins Property and Developments Limited | Real estate | 2021 |
| Hawthorn DP Ltd | Health & social care | 2025 |
| Hawthorn Inn Limited | Hospitality | 2017 |
| HAY Hill Estates Limited | Health & social care | 2003 |
| Hayley Sian Beauty Ltd | Other services | 2025 |
| Hazelwood Group Holdings Limited | Financial services | 2019 |
| Hazon Horizon Ltd | Wholesale & retail | 2026 |
| Hboss Post Limited | Transport & logistics | 2021 |
| HCC Group Ltd | Professional & scientific | 2019 |
| HCC GRP Ltd | Professional & scientific | 2012 |
| Hckj Limited | Wholesale & retail | 2025 |
| HE Crossing Loft Ltd | Manufacturing | 2026 |
| Heavenly Beauty by Cade Limited | Other services | 2025 |
| Heavenly Brows Ltd | Other services | 2023 |
| Heda TX Bicycle Co., Ltd | Wholesale & retail | 2025 |
| Hedaliya Ltd | Public administration | 2020 |
| Hedele Technology Co., Limited | Wholesale & retail | 2025 |
| HEDUC8 Hair and Beauty Supplies Limited | Wholesale & retail | 2015 |
| Heith Property Ltd | Real estate | 2022 |
| Hello Digital Limited | Information & communication | 2013 |
| Henganshangmao Ltd | Wholesale & retail | 2026 |
| Henry Huff Ltd | Extraterritorial | 2024 |
| Heron Sales and Lettings Limited | Real estate | 2020 |
| HEY Taxi Ltd | Transport & logistics | 2023 |
| HGC Civil Engineering Limited | Construction | 2017 |
| Hhkj Limited | Wholesale & retail | 2025 |
| HI Motive Communications Limited | Information & communication | 2009 |
| HI TEC Cathodic Protection Limited | Manufacturing | 1990 |
| HIG Property Ltd | Real estate | 2020 |
| High Country WWN Limited | Energy | 2015 |
| High Precision Wales Limited | Manufacturing | 1999 |
| Highfield Tanning Blackpool Limited | Other services | 2022 |
| Highfun Goods Ltd | Wholesale & retail | 2024 |
| Highgate Inn Ltd | Hospitality | 2021 |
| Hillside Fabrics Limited | Wholesale & retail | 1994 |
| Hilltop Foods Ltd | Wholesale & retail | 2019 |
| Hiwii Ltd | Manufacturing | 2025 |
| HJ Business Services Ltd | Professional & scientific | 2019 |
| HJ Property Investments Ltd | Real estate | 2017 |
| HKM Management Consultancy Limited | Professional & scientific | 2025 |
| HM Advisory Ltd | Professional & scientific | 2025 |
| HML Investments 2 Limited | Real estate | 2018 |
| HML Investments Limited | Real estate | 2018 |
| Hnlh Global Limited | Wholesale & retail | 2025 |
| HNO Holdings Limited | Financial services | 2023 |
| Hoffi Coffi Ltd. | Hospitality | 2007 |
| Holiday and Travel Consultants Ltd | Administrative & support | 2020 |
| Hollybush Tyres Limited | Wholesale & retail | 2006 |
| Hollywood Nails Bar Limited | Other services | 2017 |
| Hollywood Nails Beddau Limited | Other services | 2023 |
| Hollywood Nails CF38 Ltd | Other services | 2026 |
| Holm Theatre Ltd | Arts & recreation | 2019 |
| Home From Home Children's Day Nursery Limited | Education | 2014 |
| Homecraft Builders (South Wales) Limited | Wholesale & retail | 1981 |
| Homeguard Damproofing Limited | | 1985 |
| Homeright Ltd | Professional & scientific | 2020 |
| Honeycomb Fulfilment Limited | Transport & logistics | 2021 |
| Hong Kong Yinduo Trade Co., Limited | Wholesale & retail | 2026 |
| Hooper Training and Consultancy Services Limited | Professional & scientific | 2014 |
| Hoorab Creations Limited | Wholesale & retail | 2025 |
| Hope for Nigeria | Information & communication | 2018 |
| Hope Rescue Enterprises Ltd | Other services | 2017 |
| Horizon Legal Group Limited | Financial services | 2026 |
| Horizon Legal Limited | Other services | 2020 |
| Horton Painting Services Ltd | Construction | 2024 |
| Hothawk Ltd | Information & communication | 2023 |