| FFL Belfast Ltd | Belfast | 2025 |
| Fflamingo CIC | Cardiff | 2022 |
| Fflwr Botanicals Limited | Swansea | 2019 |
| Ffmoh Ltd | Southwark | 2017 |
| Fforest Canoes Ltd | Cardigan | 2011 |
| Fforest Events Ltd | Cardigan | 2011 |
| Fforest Hill Limited | Ammanford | 2017 |
| Fforest Star Racing Ltd | Wallasey | 2020 |
| Fform Productions Ltd. | London | 2007 |
| Ffos LAS Racecourse Limited | London | 2008 |
| Ffotogallery Wales Limited | Cardiff | 1983 |
| FFP Effects Limited | London | 2021 |
| Ffrancon Limited | London | 2006 |
| Ffrr Music Limited | London | 1987 |
| Ffrr Records Limited | London | 1986 |
| FFS Fitness Limited | Chesham | 2017 |
| Ffstival Ltd | Sheffield | 2023 |
| Ffteam Ltd | Thetford | 2025 |
| Ffts Events Ltd | Heanor | 2014 |
| Ffxap Ltd | London | 2002 |
| FG - Lmgc Limited | Holborn | 2021 |
| FG City Limited | Whetstone | 2003 |
| FG Innovations Limited | Llandudno Junction | 2023 |
| FG Personal Training Ltd | Dereham | 2019 |
| FG the PT Limited | Leeds | 2024 |
| Fg-Comps Ltd | Stoke-On-Trent | 2026 |
| FGB Events Ltd | London | 2024 |
| FGC Events Ltd | Faversham | 2015 |
| Fgcw Limited | Birmingham | 2021 |
| FGF Wellbeing Limited | Arundel | 2014 |
| FGP Entertainment Ltd | London | 2026 |
| FGR Sound Engineering Ltd | London | 2023 |
| Fgrc Ltd | Godalming | 2025 |
| FGS Entertainment Ltd | Windsor | 2025 |
| Fgtv Limited | Hitchin | 2026 |
| FH Arts and Crafts Limited | London | 2024 |
| FH Tour Management Ltd | Liverpool | 2026 |
| Fhab Limited | Blaydon-On-Tyne | 2012 |
| FHB Coaching Limited | London | 2025 |
| FHF Halfway Limited | Sheffield | 2015 |
| FHF Hillsborough Limited | Sheffield | 2012 |
| FHF Millhouses Limited | Sheffield | 2015 |
| Fhiit Club Ltd | Bedford | 2022 |
| FHL Battersea Ltd | London | 2022 |
| FHL Fulham Ltd | London | 2024 |
| FHL Streatham Ltd | London | 2025 |
| FHO Racing Limited | St Albans | 2020 |
| FI Fraser Production Management Ltd | Edinburgh | 2018 |
| FI Maritime Heritage Limited | London | 2020 |
| FI Operations UK Limited | London | 2024 |
| FI OR FO Ltd | London | 2018 |
| FI Real Competitions Limited | Wolverhampton | 2026 |
| Fiaaless Ltd | Woking | 2025 |
| Fiamma & IVO Music Limited | London | 2015 |
| Fiasko Media Ltd | London | 2011 |
| Fiber Sports Management Ltd | London | 2022 |
| Fibra Platform | London | 2019 |
| Fibre Dance & Acrobatics Ltd | Knottingley | 2019 |
| Fibre Studio Leicester Limited | Leicester | 2025 |
| Fiction & Feeling Limited | Sandy | 2016 |
| Fiction ET Limited | Penarth | 1994 |
| Fiction Films Ltd | West Sussex | 2015 |
| Fiction Republic Limited | High Wycombe | 2022 |
| Fiction Songs Limited | London | 1976 |
| Fiction Studios Ltd | London | 2019 |
| Fictional Ltd | Woking | 2015 |
| Fiddle Paradiddle Limited | Reading | 2016 |
| Fiddle-De-Sticks Ltd | Worthing | 2002 |
| Fiddlenot Limited | London | 2012 |
| Fiddlers Ferry Trading Limited | Warrington | 2024 |
| Fiddles N Flutes Festival Limited | Bedford | 2025 |
| Fidelio Arts Ltd | London | 2010 |
| Fidelio Orchestra Ltd | London | 2018 |
| Fidget and Spin Ltd | Hove | 2025 |
| Fidoawards Ltd | Cosham | 2023 |
| Fidosfun Ltd | Bracknell | 2021 |
| Fiducia Sports Consulting Limited | Glasgow | 2019 |
| Fidus Sports Limited | Bedford | 2025 |
| Field & Stage Limited | Cramlington | 2022 |
| Field Films Limited | Thame | 1978 |
| Field Golf Limited | Buntingford | 2006 |
| Field Maneuvers Creative Ltd | Newcastle Emlyn | 2024 |
| Field Mouse Designs Ltd | Welshpool | 2023 |
| Field Music Limited | Sheffield | 2005 |
| Field of Dreams | Edinburgh | 2000 |
| Field of Fitness Limited | Farnham | 2008 |
| Field of Screams Ltd | Crewe | 2024 |
| Field OFC Juniors CIC | Bradford | 2026 |
| Field OFC Limited | Bradford | 2025 |
| Field Recordings From the Future CIC | Totnes | 2025 |
| Field Rentals Limited | Gloucestershire | 1988 |
| Field Services Limited | Old Harlow | 1981 |
| Field Sports Dog Training Ltd | Radlett | 2026 |
| Field Street Fitness Limited | Loughborough | 2017 |
| Field to Fibre Limited | Hailsham | 2013 |
| Field to Office Limited | Otley | 2012 |
| Field Ventures Ltd | London | 2025 |
| Fieldfare Leisure Ltd | Spalding | 2023 |
| Fieldfree Limited | Birmingham | 1997 |
| Fieldgate Gallery Limited | London | 2007 |