| Fortium Tax Ltd | Barnet | 2026 |
| Fortiver Limited | Coventry | 2025 |
| Fortnum Home Improvements Ltd | Market Harborough | 2013 |
| Fortnums Tile Studio Ltd | Market Harborough | 2013 |
| Fortoak Group Ltd | Oldbury | 2026 |
| Fortress (Bradford) Ltd | Bradford | 2022 |
| Fortress Demolition Ltd | Romford | 2015 |
| Fortress Fire Ltd | Bristol | 2022 |
| Fortress for Investment Limited | Manchester | 2026 |
| Fortress Realisations Limited | Tunbridge Wells | 2013 |
| Fortress Scaffolding Ltd | Renfrew | 2025 |
| Fortukey Co., Ltd | Beckenham | 2024 |
| Fortuna Labori Ltd | Rotherham | 2024 |
| Fortuna Marine Yachting Construction Marble Trade Ltd | London | 2025 |
| Fortuna Scaffolding Ltd | Dorset | 1998 |
| Fortuna UK Yachting Ltd | London | 2025 |
| Fortuna Yacht Club Ltd | London | 2025 |
| Fortuna Yachting Corp Ltd | London | 2025 |
| Fortunate Destinies Ltd | London | 2022 |
| Fortune Business Consultants Limited | Reading | 2017 |
| Fortune Freeway Limited | Kenley | 2013 |
| Fortune Investments Limited | London | 2014 |
| Fortune Resources Limited | London | 1993 |
| Fortune Total Marine Engineering Co., Limited | London | 2017 |
| Fortunes Global Trading Co., Ltd | Beckenham | 2015 |
| Fortuneswell Developments Ltd. | Camberley | 2013 |
| Fortuneswell Investments NO 4 Ltd | Portland | 2017 |
| Fortview Management Limited | Portstewart | 1991 |
| Forty Eight Shelf (293) Limited | Glasgow | 2021 |
| Forty Five International Ltd | London | 2023 |
| Forum Aurea Ltd | London | 2021 |
| Forum Europe Holdings Limited | Aberdeen | 1985 |
| Forum for African Women's Development (Fawd) Ltd | London | 2019 |
| Forum for International Conciliation and Arbitration CIC | London | 2007 |
| Forum RCP Ltd | Jesmond | 2024 |
| Forum Training Limited | London | 1970 |
| Forvara Limited | Colwyn Bay | 2008 |
| Forward Business Services International Limited | | 1989 |
| Forward Electrical Services Limited | Bromsgrove | 2021 |
| Forward Global Co., Ltd | Stafford | 2018 |
| Forward Motor Trawlers Limited | | 1959 |
| Forward Nominees Limited | Birmingham | 2005 |
| Forward Properties Group Limited | Birmingham | 2022 |
| Forward Solutions Limited | Birmingham | 2024 |
| Forward Technology Fund Limited | West Midlands | 1998 |
| Forward Thinking Event Services Ltd | Basingstoke | 2015 |
| Forward Vision Limited | Ascot | 2015 |
| Forwardground Property Management Limited | Amersham | 1990 |
| Forwardspan Property Management Limited | Stratford-Upon-Avon | 1990 |
| Forwell Industry Co., Ltd | Cambridge | 2023 |
| Foryou Health Co., Ltd. | Beckenham | 2021 |
| Forza SC (Supercars) Limited | Caldicot | 2015 |
| FOS Brand Management Limited | Stratford-Upon-Avon | 2009 |
| Foscar Group Limited | London | 2017 |
| Foschell Ltd | Coventry | 2023 |
| Foshan Ceng Ceng GAO Food Co Ltd | London | 2021 |
| Foshan Daryl Electronic Technology Co., Ltd | Cardiff | 2023 |
| Foshan Golden Source Stainless Steel Co., Ltd | London | 2018 |
| Foshan JLW Intelligent Electronic Technology Co., Ltd | London | 2024 |
| Foss Development Limited | London | 2016 |
| Foss Monks Installations Ltd | Wigan | 2009 |
| Fossco 001 Limited | Wetherby | 2018 |
| Fosse (Yeovil) RTM Company Limited | Yeovil | 2004 |
| Fosse Constructing Limited | London | 2022 |
| Fosse Transport Limited | London | 2022 |
| Fosseway Magazine Limited | Gillingham | 2021 |
| Fosseway Properties Limited | Cirencester | 2012 |
| Fosso Consulting Invest Limited | London | 2021 |
| Fosso Consulting Limited | London | 2021 |
| Foster and Pollard Limited | Harrogate | 2012 |
| Foster Findlay Associates (EBT) Limited | Newcastle Upon Tyne | 2011 |
| Foster Tuition Ltd | Lincoln | 2024 |
| Foster Wheeler (Process Plants) Limited | Knutsford | 1974 |
| Foster Wheeler Environmental (UK) Limited | Knutsford | 1982 |
| Fostering Safety Ltd | Braintree | 2014 |
| Fosters Jewellers Ltd | Bristol | 2008 |
| Fostertax Limited | Cramlington | 2006 |
| Fotas Limited | Sutton Coldfield | 2004 |
| Foteng International Limited | Kington | 2016 |
| Fotheringhay Farming Co. Limited | Northamptonshire | 1969 |
| Fotini Properties Limited | London | 2014 |
| Fotklinikken Balestrand Invest Limited | London | 2025 |
| Fotklinikken Balestrand Limited | London | 2025 |
| Foto-Digital Ltd | Wisbech | 2023 |
| Fotograss Limited | Whitegate | 2009 |
| Fotoh Ltd | Coventry | 2021 |
| Fotovalue Limited | Sheffield | 1954 |
| Fotp Research Limited | Somerset | 2007 |
| Fouberts Management Ltd | London | 2006 |
| Fouberts Place Subsidiary NO.4 Limited | London | 1987 |
| Foufou Ltd | Kington | 2020 |
| Foulsham Road 1960 Limited | Thornton Heath | 2014 |
| Found Furniture Limited | Biggleswade | 2022 |
| Found in Bristol Limited | Tavistock | 2016 |
| Foundahome Limited | Glasgow | 2007 |
| Foundation Capital Limited | London | 2003 |
| Foundational Approach Limited | Leeds | 1973 |
| Foundations Building Services Ltd | Newcastle Upon Tyne | 2020 |
| Foundations for Life Ltd | Leeds | 2008 |
| Founder Facilitation Services Limited | Chesham | 2024 |