| Fairbairn Mechanical Ltd | Ashington | 2014 |
| Fairfern Trading Limited | Bracknell | 2025 |
| Fairfield Betula Limited | London | 2002 |
| Fairfield Energy Holdings Limited | London | 2005 |
| Fairfield Energy Limited | London | 2005 |
| Fairfield Fagus Limited | London | 2005 |
| Fairhaven Instrumentation Ltd | Falkirk | 2015 |
| Fairmont Resources Limited | London | 2019 |
| Falcon Petroleum Limited | London | 2025 |
| Fall Factor Zero Limited | Haddington | 2004 |
| Fanam Ltd | Caterham | 2024 |
| Faramade Limited | Birmingham | 2023 |
| Farmington Natural Stone Limited | Cheltenham | 1995 |
| Farmington Services Limited | Cheltenham | 2008 |
| Farquhar Decommissioning Ltd | Linlithgow | 2019 |
| Farren.T Ltd | Perth | 2022 |
| Farrow OGS Limited | North Walsham | 2008 |
| Faso Minerals Limited | London | 2021 |
| Faulkner Consolidated Minerals Limited | Stone | 2024 |
| Fawcett Access Ltd | Hawes | 2022 |
| Fawcett Aggregates Limited | Lincoln | 2021 |
| FBC Mining (BA) Limited | Leicester | 2014 |
| Fcswt Ltd | Isle Of Lewis | 2018 |
| FD International Limited | Cleator Moor | 2025 |
| FE Chromium (UK) Limited | Stoke-On-Trent | 2011 |
| Feachd Nàdair Ltd | Musselburgh | 2025 |
| Fear of Toast Limited | Aberdeen | 2006 |
| Fedderate R Investments Limited | Turriff | 2016 |
| Femcoks Engineering Services Limited | Rochdale | 2021 |
| Fenny-Global Services Ltd | Romford | 2019 |
| Fenstone Minerals Limited | East Yorkshire | 1993 |
| Fergana OIL Rfinery Plant Ltd | Harlow | 2025 |
| Ferguson Marine Services Limited | Glasgow | 2004 |
| Ferns Aggregates Limited | Maidstone | 2019 |
| Ferrexpo PLC | London | 2005 |
| Ferrocom Steel Ltd | London | 2020 |
| Fertec Ltd | Peterhead | 2019 |
| Fetlar Energy Limited | Fraserburgh | 2023 |
| Fettercairn Engineering Services Limited | Glasgow | 2012 |
| Fezzan for Geophysical Services Ltd | Birmingham | 2023 |
| Ffos-Y-Fran (Commoners) Limited | Merthyr Tydfil | 2003 |
| Ffrench Exploration Consulting Limited | Sevenoaks | 2020 |
| Ffynonau Duon Mines Limited | Bargoed | 1971 |
| FGB Minerals Limited | Wakefield | 2008 |
| Fgps Limited | Brighton | 2000 |
| Fibresand UK (Mansfield) Limited | Mansfield | 1999 |
| Fibreturf Limited | Mansfield | 2003 |
| Field Development Specialists Ltd. | London | 2005 |
| Field Energy Services Ltd | Liverpool | 2021 |
| Field View Technical Services Ltd | Mauchline | 2013 |
| Fife NDT Inspection Services Limited | St. Andrews | 2014 |
| Filacontexta Ltd | Godalming | 2020 |
| Film-Ocean Ltd. | Ellon | 2004 |
| Filtercite Ltd | Ammanford | 2016 |
| Filtratech Limited | Trowbridge | 2014 |
| Fina Exploration Limited | London | 1964 |
| Fina Petroleum Development Limited | London | 1962 |
| Financial America OIL Company Limited | London | 2024 |
| Fincammur Ltd | Montrose | 2016 |
| Find That Leak Ltd | Great Yarmouth | 2026 |
| Finder Energy UK Limited | London | 2019 |
| Findlay Access Services Ltd. | North Berwick | 2003 |
| Findt Ltd | Dalgety Bay | 2026 |
| Finewide Limited | Aberdeen | 1988 |
| Finland Aifuman Agriculture Technology Ltd | Cambridge | 2026 |
| Finland Investments Limited | London | 2010 |
| Finland Ngrola Crop Nutrition Co., Ltd | London | 2023 |
| Finland Wamav International Ltd | London | 2025 |
| Finley Star Limited | Banff | 2025 |
| Finn Marine Services Limited | Manchester | 2020 |
| Fintracom Limited | London | 2022 |
| Fintrad UK Ltd | London | 2024 |
| Firestone Diamonds Limited | Worthing | 1998 |
| Firm Engineering Ltd | Laurencekirk | 2024 |
| First Africa Metals Limited | London | 2023 |
| First Class Metals PLC | Preston | 2021 |
| First Global Services Ltd | London | 2010 |
| First Inspection and Testing Services Ltd | Inverurie | 2018 |
| First Marine Solutions Limited | Aberdeen | 2008 |
| First NDT Ltd | Oldham | 2025 |
| First OIL Investments | Aberdeen | 2019 |
| First Test Minerals Ltd | St. Austell | 2014 |
| First TIN PLC | London | 2012 |
| First Universal Ltd | Tyne And Wear | 2003 |
| Fiscal Instrumentation Ltd. | Aberdeen | 2006 |
| Fish-Tech UK Limited | Insch | 2013 |
| Fishermen's Petroleum Company Limited | Aberdeen | 1980 |
| Fitikof Ltd | Glasgow | 2012 |
| Fitzroy QLD Resources Limited | Reading | 2016 |
| Fitzwise Limited | Chesterfield | 1973 |
| Fivestanks Engineering Ltd | Broxburn | 2016 |
| FJM Marine Services Ltd | London | 2023 |
| Fjord International Offshore and Towing Company Limited | Orpington | 2017 |
| FK1 Electrical Ltd | Falkirk | 2019 |
| FKF Engineering Ltd. | Peterhead | 2008 |
| Flange Management Services Ltd | Cramlington | 2025 |
| Flanqs Ltd | South Shields | 2026 |
| Flappit Quarry Co. Limited | Haworth | 1996 |
| Flemco Intervention Services Ltd | Montrose | 2013 |
| Fletcher Industries Limited | Aberdeen | 2008 |