| Fletcher Logistics Ltd | Montrose | 2014 |
| Fletcher Offshore Services Limited | Aberdeen | 2016 |
| Fletcher Supply Vessels Limited | Aberdeen | 2016 |
| Flintridge Resources Limited | Bristol | 2013 |
| Flintshire Sand and Gravel Limited | Telford | 2018 |
| Flintx Limited | Liskeard | 2025 |
| Flixton Lakes Limited | Lowestoft | 2022 |
| Flloyd's Rope Access Ltd | London | 2021 |
| Floatel UK Contractor Limited | Aberdeen | 2015 |
| Floating Grid LNG Limited | Aberdeen | 2026 |
| Flofields Limited | London | 2000 |
| Florence Petroleum Ltd | Altrincham | 2020 |
| Florentine Logistics Limited | Cirencester | 2014 |
| Flowell Services Ltd | Montrose | 2008 |
| Flowline Solutions Limited | Aberdeen | 2017 |
| Floxpat Petroleum & Energy Services Limited | Sutton | 2011 |
| Fluid AI Limited | Wem | 2025 |
| Fluorspar Ventures Limited | Leeds | 2021 |
| Flyte Parsons Limited | Brecon | 2019 |
| FM Inspection Ltd | Dundee | 2014 |
| FMC Kongsberg Services Limited | Newcastle Upon Tyne | 2003 |
| FMC Technologies Limited | Newcastle Upon Tyne | 1931 |
| Focus 3 Ltd | Grimsby | 2021 |
| Focus OIL and GAS Limited | Burntisland | 2008 |
| Focus Optimisation Services Limited | Aberdeen | 2018 |
| Fodiens in Posterum Ltd | Chigwell | 2017 |
| Foelfach Stone Limited | London | 2016 |
| Folk Inspection Services Ltd | Aberdeen | 2022 |
| Folkes Plant & Aggregates Limited | Great Yarmouth | 1998 |
| Folkfilm Productions Limited | London | 2009 |
| Folkton Wold Quarry Limited | Scarborough | 2006 |
| Fontana Solutions Limited | Harrow | 2000 |
| Fontec Engineering Limited | Aberdeenshire | 2007 |
| Foord First Limited | Derby | 2019 |
| Forbes Well Services Ltd | Aberdeen | 2013 |
| Fordath Limited | London | 1920 |
| Fordrill Limited | Essex | 1996 |
| Foremast Ltd | Liverpool | 2023 |
| Foresea Drilling United Kingdom Ltd | Reading | 2022 |
| Forest of Dean Stone Firms Limited | Cheltenham | 2006 |
| Forest Pennant Ltd | Cheltenham | 2015 |
| Forest Stoneyard Limited | Lydney | 2020 |
| Forge North Resources Limited | Weekley | 2020 |
| Foro Energy UK Limited | Liverpool | 2015 |
| Forster Oil&Gas Limited | Montrose | 2014 |
| Forthtech Services Ltd | Falkirk | 2018 |
| Fortress Fishing & Milling Limited | Aberdeen | 2026 |
| Fortune OIL Limited | London | 1987 |
| Fortunes Gate Mastercraft Limited | Leigh On Sea | 2024 |
| Forum Energy Limited | London | 2005 |
| Forum Energy Services Limited | Isleworth | 2015 |
| Forum Germany Holdings Limited | Aberdeen | 2011 |
| Forward Sound Limited | Durham | 2008 |
| Fose Ltd | London | 2026 |
| Fossoil Ltd | Burntwood | 2020 |
| Foster Marine Offshore Limited | Banchory | 2024 |
| Foster Offshore Limited | St. Andrews | 2018 |
| Foster Primus Ltd | Aberdeen | 2026 |
| Fosterz Limited | Hessle | 2013 |
| Fotros Co Ltd | Derby | 2024 |
| Fourquest Energy (UK) Limited | Middlesbrough | 2021 |
| FOX Brothers (Bacup) Limited | Blackpool | 2020 |
| FOX Brothers (Leyland) Ltd | Blackpool | 1984 |
| FOX Earthworks Limited | Market Rasen | 2024 |
| FOX Hall Country Supplies Ltd | Goole | 2018 |
| FOX Marble Limited | London | 2011 |
| FOX ST Limited | Blandford Forum | 2024 |
| Foxdan Limited | Glasgow | 2026 |
| Foxley Energy Limited | Aberdeen | 2016 |
| Foyzer Services Limited | Dundee | 2018 |
| FP Mccann Limited | Magherafelt, | 1979 |
| FP Offshore Services Limited | Aboyne | 2019 |
| Fracture Technologies Limited | Fowey | 1997 |
| Framecore Capital Limited | London | 2023 |
| France Reading Saint-Fez Bioengineering Limited | Cambridge | 2024 |
| Frank's International Limited | Reading | 1986 |
| Fraser Aggregate Services Ltd | Farnham | 2010 |
| Fraser Mcmaster Limited | Dumfries | 2009 |
| Freck Fraser Ltd | Inverness | 2016 |
| Frederick Marine Services Limited | Liverpool | 2013 |
| Fresh Start Managing Ltd | Goole | 2011 |
| Fresnillo PLC | London | 2007 |
| Freyja Materials Limited | London | 2023 |
| Friars Pits Limited | Chelmsford | 2015 |
| Friarshill Logistics Limited | Aberdeen | 2014 |
| Friendship Scouts Group Ltd | Watford | 2018 |
| Fries Crop Science Australia Limited | Stafford | 2025 |
| Frimstone Limited | Maidenhead | 1975 |
| Frome Auto Electrical Quarrying Ltd | Frome | 2022 |
| Frontier Exploration Group Ltd | London | 2026 |
| Frontier Metals Ltd | London | 2026 |
| Frood Rope Access Ltd | Dundee | 2024 |
| Fruit-Full Appliances Ltd | London | 2019 |
| FS Balmoral Limited | Aberdeen | 2023 |
| FS Cygnus Limited | Aberdeen | 2022 |
| FS Sceptre Limited | Aberdeen | 2021 |
| FSK Solutions Limited | Ellon | 2013 |
| Fuel POD Systems Ltd | Belfast | 2012 |
| Fugro Subsea Services Ltd | Bridge Of Don | 1987 |
| Fugson International Limited | Glasgow | 2025 |