| Horrells Farmers Limited | Peterborough | 1965 |
| Horse 1ST Training Limited | Sutton Coldfield | 2020 |
| Horse 4 Thought Ltd | Sidcup | 2020 |
| Horse Ambulance Service Ltd | Burton-On-Trent | 2001 |
| Horse and Harmony Limited | York | 2025 |
| Horse and Hound Sales Ltd | Northwich | 2024 |
| Horse and Human Limited | Newark | 2023 |
| Horse Energy Holdings Ltd | Paisley | 2025 |
| Horse HOW to Academy Ltd | Stirlingshire | 2011 |
| Horse Mate Community Interest Company | Jedburgh | 2025 |
| Horse Next Door Equestrian Services Ltd | Leeds | 2013 |
| Horse Passport Agency Ltd | Ellesmere | 2003 |
| Horse Transport Professionals Ltd | Ballymena | 2021 |
| Horse World of Bawtry Limited | London | 2020 |
| Horsechoice Ltd | Edinburgh | 2025 |
| Horsecombe Vale Conservation Limited | Bath | 2011 |
| Horsehaven Limited | Westcott | 1976 |
| Horsemanship Hub Ltd | Little Marlow | 2022 |
| Horses 4 Life CIC | Newton Abbot | 2021 |
| Horses and Ponies Protection Association | Nr Burnley | 2000 |
| Horses for Courses Limited | Hook | 2000 |
| Horses for Good Ltd | Wellingborough | 2021 |
| Horses in Nature CIC | Monmouth | 2025 |
| Horsesense Farms Limited | Henley-In-Arden | 1995 |
| Horseshoe Contracting Limited | Burscough | 2022 |
| Horseshoe Pool Ltd | Oldham | 2024 |
| Horsetec Limited | Beverley | 2020 |
| Horseway Holdings Limited | Chatteris | 2012 |
| Horsewise Limited | Hay-On-Wye | 2010 |
| Horsewold Farms Limited | Driffield | 2004 |
| Horsfields (Church Farm) 1984 Limited | Taunton | 1984 |
| Horsfields (Swithen Farm) 1984 Limited | Barnsley | 1984 |
| Horsfields Holdings Limited | Wakefield | 2023 |
| Horsham Tree Services Limited | Keston, | 2022 |
| Horsley Brook Farms Ltd | Nuneaton | 2015 |
| Horson Farms Limited | Exeter | 2000 |
| Hortech Systems Limited | Spalding Lincolnshire | 1989 |
| Hortensia Farm Ltd | Penzance | 2020 |
| Horthorn Equestrian & Livery Limited | Chester | 2024 |
| Horthorn Livery Limited | Chester | 2024 |
| Horticare Environmental Services Limited | Birmingham | 1992 |
| Horticman Limited | Ware | 2006 |
| Horticouture Ltd | London | 2024 |
| Horticultural and Agricultural Industrial Drone Services Ltd | Brighton | 2024 |
| Horticulture Crop Protection UK Limited | Louth | 2022 |
| Horticulture Specialist Nursery Ltd | Newcastle Upon Tyne | 2023 |
| Hortimate Ltd | Broadstone | 2005 |
| Hortinspect Limited | Malvern | 2008 |
| Hortiserv Ltd | Harpenden | 2020 |
| Horton Bloodstock Ltd | Shrewsbury | 2021 |
| Horton Community Farm Co-Operative Limited | Bradford | 2011 |
| Horton Farms Ltd | Dereham | 2004 |
| Horton House Farm Limited | Wilts | 1961 |
| Hortus Blackheath Limited | London | 2002 |
| Hortus Group Ltd | Moreton-In-Marsh | 2025 |
| Hortus Loci Landscapes Ltd | Hook | 2018 |
| Hortus Loci Limited | Hound Green | 2007 |
| Hortus Ltd | Congleton | 2025 |
| HOS Honey Limited | Robertsbridge | 2023 |
| Hosanna Fish Ltd | Norwich | 2020 |
| Hosegood Farm Services Ltd | Crediton | 2022 |
| Hoseley Farms Limited | Wrexham | 2004 |
| Hosford Farms Limited | Dorchester | 2026 |
| Hosier Brothers Limited | Marlborough | 1985 |
| Hoskin Plant & Civils Limited | Plymouth | 2024 |
| Hoskins & Vickery Limited | Taunton | 2015 |
| Hoss Shoes Limited | Loughborough | 2012 |
| Hot Fishin' Ltd | London | 2019 |
| Hot Hatch Hero's Limited | Tunbridge Wells | 2016 |
| Hot Rails Consultants Limited | | 2003 |
| Hotchpotch Organics Ltd | Pershore | 2021 |
| Hotelkitty Limited | Basildon | 2025 |
| Hoten Ltd | Cardiff | 2022 |
| Hotshot Henley Limited | Newbury | 2023 |
| Houghton Bloodstock UK Limited | Sudbury | 2005 |
| Houghton Brown Enterprises Limited | Kettering | 1976 |
| Houghton Community Black BEE Project CIC | Stockbridge | 2020 |
| Houghton Hall Equestrian and Alpaca Centre Limited | Huntingdon | 2012 |
| Houghton Produce Limited | Spalding | 2002 |
| Houghton Springs Trout Farm Limited | Winterborne Houghton | 2025 |
| Houldsworth Crescent Allotments Limited | Leicester | 1997 |
| Hound Around Day Care Limited | Edinburgh | 2019 |
| Hound Hall Ltd | Market Drayton | 2022 |
| Hound Wood Management Limited | Romsey | 1995 |
| Houndandblossom Ltd | London | 2022 |
| Houndplus Ltd | Bristol | 2022 |
| Hounds & Hooves Limited | Dorchester | 2016 |
| Hounds & Hunters Limited | Cheltenham | 2024 |
| Hounds at Home Ltd | Basildon | 2019 |
| Hounds of Hackney Limited | London | 2022 |
| Hounds of Hertfordshire Ltd | London | 2025 |
| House & Sons Limited | Bridgwater | 2017 |
| House of Bulls (Belfast) Ltd | Belfast | 2021 |
| House of Jacks Limited | Weston Super Mare | 2024 |
| House of Wallensis Limited | Ely | 2017 |
| House of Whittle Ltd | London | 2019 |
| House of Woulfe Polo Ltd | London | 2025 |
| Housebyres Farming Ltd | Halifax | 2006 |
| Houseman & Falshaw Limited | Leeds | 1979 |
| Housman Tree Services Ltd | Oswestry | 2024 |