| H.S. Hommers & Sons (Dutch Bulbs) Limited | Codsall Wolverhampton | 1961 |
| H.S. Petch & Sons Limited | Great Ayton | 1962 |
| H.Snelson & SON Limited | Claverley | 1964 |
| H.T.Smith(Farms)Limited | Braintree | 1952 |
| H.Timmis(Farms)Limited | Newport | 1954 |
| H.W. Agriculture Ltd | Crewe | 2015 |
| H.W. Colley & SON Limited | East Yorkshire | 2004 |
| H.W.Clothier Milton-Westcombe Farms Limited | Nr Shepton Mallet | 1959 |
| H.W.E.Timm(Farmers)Limited | Howden | 1958 |
| H.Weston & Sons Limited | Ledbury | 1960 |
| H.Wiseman & Son(Wimbish)Limited | Saffron Walden | 1964 |
| H2 Contractors Limited | Stafford | 2019 |
| H2 Environmental Limited | Devon | 2001 |
| H2 Global Trading Ltd | Canterbury | 2024 |
| H2GROW Ltd | Ferndown | 2023 |
| H2H Yachts & Jets Ltd | London | 2019 |
| H2O Hydro Ltd | Thornhill | 2013 |
| H2OMAX Ltd | Truro | 2025 |
| HA Crafts Ltd | Wolverhampton | 2026 |
| Haaco Limited | Fraserburgh | 2007 |
| Haag Limited | Eye | 1964 |
| Haag's Farms Limited | Eye | 2025 |
| Haag's Norfolk & Suffolk Farms Limited | Eye | 1956 |
| HAB Poultry Ltd | Frinton On Sea | 2020 |
| Habarakah Ltd | London | 2025 |
| Habitat Creation Limited | London | 2025 |
| Habitat NW Ltd | Wirral | 2024 |
| Habton Farms | Scarborough | 1970 |
| Habton Racing | Scarborough | 2020 |
| Hack Green Lakes Ltd | Stoke On Trent | 2022 |
| Hackford Farms Limited | Norwich | 1970 |
| Hackness Sporting Society 2020 Limited | Leyburn | 2020 |
| Hackney Herbal C.I.C. | London | 2018 |
| Hackney Horse Society(The) | Warminster | 1884 |
| Hackthorn Manor Limited | Lincoln | 1976 |
| Hackworthy Ltd | Wells | 2020 |
| Hadden Farm Limited | Edinburgh | 2018 |
| Hadden Holdings Limited | Laurencekirk | 2018 |
| Haddenham Stud Farm Limited | Haddenham | 2013 |
| Haddiscoe Manor Farm Limited | Norwich | 1955 |
| Haddo Energy Limited | Ellon | 2008 |
| Haddon Farms Limited | Holmfirth | 2018 |
| Hademore Hounds Ltd. | Lichfield | 2018 |
| Hadingham Farriery Limited | Beccles | 2014 |
| Hadleigh Agriculture Limited | Marlborough | 2016 |
| Hadley Farms Limited | Shipston-On-Stour | 1997 |
| Hadley Road Community Allotment CIC | Mitcham | 2023 |
| Hadley Services (Lincs) Limited | Barnetby | 2024 |
| Hadraj Limited | Lutterworth | 2020 |
| Hadrian A.I. Services Limited | Carlisle | 2005 |
| Hadsham Enterprises Limited | Banbury | 2017 |
| Hadspen Valley Ltd | Castle Cary | 2025 |
| Hael Colour Limited | Clynderwen | 2024 |
| Haerfest Limited | High Wycombe | 2024 |
| HAF Organic Ltd | Maesteg | 2023 |
| Hafan Hendre CYF. | Corwen | 2021 |
| Hafod Ganol Agri Ltd | Cardiff | 2024 |
| Hafod Walled Garden Group CIC | Ystrad Meurig | 2019 |
| Hafod-Y-Bryn Cattery Limited | Colwyn Bay | 2014 |
| Hafod-Y-Bryn Kennels Limited | Colwyn Bay | 2013 |
| Hafodneddyn Feeds Ltd | Carmarthen | 2021 |
| Hafodunos Farms Limited | Mold | 1977 |
| Hagag Limited | Ipswich | 2016 |
| Hagan Homes Limited | Ballyclare | 1988 |
| Hagefield Ltd | Dollar | 2026 |
| Haggitt Hill Holdings Limited | Yarm | 2024 |
| Hague Farming Limited | Sheffield | 1988 |
| Hague Farms Limited | Chichester | 1984 |
| Hague Habitats Limited | Hyde | 2025 |
| Hagues Farming & Events Ltd | Ripon | 2025 |
| Haig Orchards Limited | Hereford | 2017 |
| Haigh Farriery Limited | Driffield | 2024 |
| Haigh Hoofcare Ltd | Leeds | 2023 |
| Hail Weston Farms Limited | Pe19 5Jw | 1985 |
| Haile Moor Mine Limited | Egremont | 2000 |
| Hailea Limited | Lincoln | 2019 |
| Hailey Community Woodland Limited | Witney | 2002 |
| Haines Construction Limited | Eastleigh | 1998 |
| Haines Farm Eggs Limited | Reading | 2011 |
| Haines Holding (Southern) Limited | Calne | 2017 |
| Haining Garden Cottage Ltd | Selkirk | 2023 |
| Hainoc Limited | Newton Abbot | 2004 |
| Hainton Enterprises Limited | Market Rasen | 2012 |
| Hair OFF the Dog (Congleton) Ltd | Congleton | 2007 |
| Hairsine Pigs Limited | Driffield | 2002 |
| Hairy Bear Tree Surgery Limited | Leicester | 2017 |
| Hairyaxe Ltd | Neath | 2025 |
| Hajdax Pet Services Ltd | Merthyr Tydfil | 2022 |
| HAL Forestry Limited | Hereford | 2012 |
| Halbeath Farm Limited | | 1979 |
| Halberton Poultry Limited | Tiverton | 1963 |
| Halcyon Fishing Ltd | Orkney | 2026 |
| Halcyon Habitats Ltd | Rothesay | 2025 |
| Hale Associates Limited | Swindon | 2002 |
| Hale Estate Berkshire Ltd | Maidenhead | 2024 |
| Halebourne Nurseries Limited | Woking | 2007 |
| Hales Limousins Ltd | Cambridge | 2017 |
| Halesend Estate Limited | London | 2013 |
| Half Acre Farm Limited | Belper | 2017 |
| Half Moon Community CIC | Totnes | 2024 |