| Finnforest Baco Production Ltd | London | 2020 |
| Finnimore Farms Ltd | Launceston | 2025 |
| Finns Farm 2021 Limited | Horley | 2020 |
| Fint Ltd. | Peterhead | 2003 |
| Fintra Bay Fishing Ltd | Belfast | 2024 |
| Fintray Farms Limited | Peterborough | 2010 |
| Finwood Enterprises Limited | Henley In Arden | 2003 |
| Fiocastle Ltd | Clitheroe | 2023 |
| FIR Farm Holdings Limited | Bristol | 2012 |
| FIR Farm Limited | Bristol | 2021 |
| FIR Forestry Ltd | Creetown, Newton Stewart | 2020 |
| FIR Tree Farm (Yorkshire) Limited | York | 2015 |
| FIR Tree Farm Kent Ltd | Sevenoaks | 2024 |
| FIR Tree Farm Limited | Adderbury | 1999 |
| FIR Tree Farm Stables Limited | Ipswich | 2025 |
| FIR Tree Rescue Ranch Community Interest Company | Cowes | 2026 |
| Firbeck Farmhouse Livery Limited | Worksop | 2023 |
| Fircroft Tree Surgery Limited | Watford | 2014 |
| Fire and Stars Ltd | Newton Burgoland | 2021 |
| Firebird Stud Limited | Cambridge | 2009 |
| Firedog Creative CIC | Rhosneigr | 2026 |
| Firefly Services Ltd | Sunbury-On-Thames | 2015 |
| Firewood 2 U Limited | Halesworth | 2018 |
| Firewood and Chip Arboricultural Services Limited | Southam | 2017 |
| Firewood Fuel MK Ltd | Milton Keynes | 2020 |
| Firewood Ireland Ltd | Belfast | 2018 |
| Firewood Supplies Dromore Ltd | Dromore | 2025 |
| Firgrove Farm Ltd | Magheralin | 2021 |
| Firle Farms Limited | Lewes | 1948 |
| Firm of a L Common Limited | Melrose | 2019 |
| Firmkill Ltd | Bexley | 2025 |
| Firs Farm Contracting Limited | Lawford | 2025 |
| Firs Farm Nurseries Limited | Scropton | 2006 |
| First Bloodstock Limited | Brighton | 2021 |
| First Choice Landscapes Limited | Wakefield | 2002 |
| First Class Timber Ltd | Northampton | 2019 |
| First Land Group Ltd | London | 2022 |
| First Priority Marine Ltd | Ramsgate | 2024 |
| First Step Brothers Ltd | London | 2022 |
| First Wave Equestrian Limited | Eastleigh | 2021 |
| First Window & Doors Limited | Portsmouth | 2003 |
| Firstfruits Environmental Services C.I.C. | Rochester | 2021 |
| Firstline Pets Ltd | London | 2020 |
| Firth Farming Limited | Dumfriesshire | 2006 |
| Firth Produce Ltd | Spalding | 2021 |
| Firthfield Farm Ltd | Castleford | 2014 |
| Firtree Ponies Ltd | Wetherby | 2026 |
| Firwood Court Livery Stables Ltd | Herne Bay | 2010 |
| Firwood Farm Eggs Ltd | Preston | 2007 |
| Firwood Poultry Limited | Taunton | 2009 |
| Fischer Farms 1 Ltd | Burton-On-Trent, | 2018 |
| Fischer Farms 2 Ltd | Burton-On-Trent, | 2019 |
| Fischer Farms 3 Ltd | Burton-On-Trent, | 2021 |
| Fischer Farms Holdco Limited | Burton-On-Trent, | 2018 |
| Fischer Farms Ltd | Burton-On-Trent, | 2016 |
| Fischer Farms Technology Limited | Barton-Under-Needwood | 2024 |
| Fiscrop Limited | Newport | 2021 |
| Fish 4 Life Angling Academy | Leigh On Sea | 2016 |
| Fish and Pond Centre Limited | Northampton | 2001 |
| Fish Cake Aquatics Ltd | Driffield | 2026 |
| Fish Disease Dolau Ltd. | Llandrindod Wells | 2014 |
| Fish Diseases Ltd | Leicester | 2024 |
| Fish Embassy Ltd | Stevenage | 2025 |
| Fish Help Concept Ltd | Harrow | 2024 |
| Fish Hunter Ltd. | Lowestoft | 2018 |
| Fish Industry Training Association (Highlands & Islands) Limited | Aberdeen | 2005 |
| Fish Management Systems Ltd | Carrickfergus | 2019 |
| Fish Mourne Limited | Coleraine | 2010 |
| Fish Network Limited | North Molton | 1989 |
| Fish on Scotland Ltd | Maybole | 2025 |
| Fish Port Fish Mongers Ltd | South Croydon | 2018 |
| Fish Research & Consultancy Ltd | Kingsbridge | 2002 |
| Fish Versity Ltd | Bedford | 2026 |
| Fishable Lakes Limited | Colchester | 2021 |
| Fishbourne Apiaries Limited | Chichester | 1981 |
| Fishdance Limited | Hampton | 2013 |
| Fisher & Ridgway, Limited | Nuneaton | 1952 |
| Fisher Dawn Limited | Peterhead | 2010 |
| Fisher Eggs Ltd | Whitehaven | 2005 |
| Fisher Equestrian Limited | Reading | 2008 |
| Fisher Farming Limited | Cumbria | 2006 |
| Fisheries Innovation & Sustainability | Pitlochry | 2014 |
| Fisheries JLR ( UK ) Limited | London | 2018 |
| Fisheries Management Scotland | Edinburgh | 2018 |
| Fishers Pond Limited | Winchester | 2003 |
| Fisherton Manor Farm | Winchester | 2003 |
| Fisherton Processing Limited | Warminster | 2021 |
| Fishfrom Limited | Glasgow | 2012 |
| Fishgen Limited | Llanelli | 1996 |
| Fishing Association Ltd | Thrapston | 2021 |
| Fishing Company Wirons Limited | Caterham | 1992 |
| Fishing IS Therapy CIC | Dover | 2025 |
| Fishing Management (NE) Limited | North Shields | 2007 |
| Fishing Windermere Limited | Grange-Over-Sands | 2025 |
| Fishing With Vito Ltd | London | 2025 |
| Fishingessex Ltd | West Horndon | 2020 |
| Fishinity Pro Ltd | Leigh-On-Sea | 2025 |
| Fishkeeper Scotland Limited | Edinburgh | 2015 |
| Fishleighs of Galsworthy Limited | Bideford | 2019 |
| Fishtek Limited | Cheshire | 1999 |