| Fibersat Ltd | Information & communication | 2020 |
| Fibre Clear Limited | Wholesale & retail | 1999 |
| Fibre Training Limited | Administrative & support | 2003 |
| Fibreflow Limited | Manufacturing | 2018 |
| Fibres Worldwide Limited | | 2005 |
| Ficsec Limited | Financial services | 2023 |
| Fidata Limited | Information & communication | 2022 |
| Fidato Nexus Ltd | Construction | 2023 |
| Fiddes & SON Limited | Manufacturing | 1984 |
| Fiddes Glass Coatings Limited | Administrative & support | 2005 |
| Fidem Castra Properties Limited | Financial services | 2024 |
| Fidlas House Management Limited | Households | 2025 |
| Fiducia Global Solutions Limited | Information & communication | 2019 |
| Fiducia Security Ltd | Administrative & support | 2025 |
| Fiee-Forever Limited | Wholesale & retail | 2025 |
| Field Bar GIN Limited | Wholesale & retail | 2017 |
| Field Dog Fairs Ltd | Administrative & support | 2013 |
| Field Group Services Limited | Professional & scientific | 2023 |
| Field Online Saas Ltd | Information & communication | 2025 |
| Field Services Tech Ltd | Construction | 2025 |
| Field Tax Ltd | Professional & scientific | 2024 |
| Field Tech Engineering Services Limited | Professional & scientific | 2025 |
| Fieldcote Limited | Health & social care | 2020 |
| Fieldmere Ltd | Wholesale & retail | 2025 |
| Fieldstone Properties Ltd | Real estate | 2025 |
| Fieldtech Rentals Ltd | Administrative & support | 2025 |
| Fieldwell Ltd | Real estate | 2022 |
| Fieldwork Culture LLP | | 2013 |
| Fiery Jacks C.I.C. | Education | 2021 |
| Fiery Rainforest Limited | Arts & recreation | 2021 |
| Fiesta Vacations Limited | Administrative & support | 2024 |
| Fifco Ltd | Information & communication | 2026 |
| Fifreed | Professional & scientific | 2023 |
| Fifteen Sectors International Group Ltd | Transport & logistics | 2024 |
| Fifth Sense London Limited | Wholesale & retail | 2018 |
| Fifty Second Ltd | Professional & scientific | 2006 |
| Fifty SIX Group Ltd | Arts & recreation | 2018 |
| FIG Tree HR Ltd | Administrative & support | 2022 |
| Figari Capital Ltd | Financial services | 2021 |
| Figbit Limited | Other services | 2024 |
| Fighting. Ltd | Wholesale & retail | 2020 |
| Figmall Limited | Wholesale & retail | 2022 |
| Fil-Cymru Care Services Ltd | Health & social care | 2021 |
| Filanzo Ltd | Wholesale & retail | 2024 |
| Filbert Realisations NO 1 PLC | Arts & recreation | 1919 |
| Filbuk 313 Limited | Extraterritorial | 1993 |
| Filia Group Ltd | Construction | 2020 |
| Filii Construction Ltd | Construction | 2019 |
| Filin Ltd | Administrative & support | 2016 |
| Filinum Ltd | Wholesale & retail | 2025 |
| Filipek Estates Ltd | Real estate | 2025 |
| Fillers Pro Ltd | Wholesale & retail | 2018 |
| Fillyboo Limited | Wholesale & retail | 2024 |
| Film and Television Solutions Group Limited | Administrative & support | 2025 |
| Film Lighting Creative Ltd | Construction | 2022 |
| Filmawit Event & Dekor Limited | Extraterritorial | 2025 |
| Filmspiel CYF | Information & communication | 2003 |
| Filtered Recruitment Ltd | Administrative & support | 2021 |
| Filterquip Limited | Wholesale & retail | 2021 |
| Filtondale Limited | Real estate | 1987 |
| Fima Global Limited | Wholesale & retail | 2013 |
| FIMAC23 Ltd | Financial services | 2023 |
| Fimax Property Limited | Real estate | 2024 |
| Fimo Ltd | Financial services | 2021 |
| FIMO24 Ltd | Other services | 2022 |
| FIN Ltd | Real estate | 2019 |
| FIN Media Ltd | Professional & scientific | 2009 |
| Fina Recruitment Ltd | Administrative & support | 2025 |
| Finactiveun Limited | Other services | 2022 |
| Final Checks Hair and Makeup Services Limited | Other services | 2012 |
| Final Element Limited | Professional & scientific | 2017 |
| Final Recruitment Limited | Administrative & support | 2019 |
| Final Value Ltd. | Financial services | 2009 |
| Finalrentals Limited | Information & communication | 2022 |
| Finance Angels Ltd | Financial services | 2012 |
| Finance Global Ltd | Financial services | 2011 |
| Finance Guru Ltd | Professional & scientific | 2025 |
| Finance Management Ltd | Wholesale & retail | 2018 |
| Financial Crime Compliance Solutions Limited | Professional & scientific | 2017 |
| Financial Initiatives Limited | Financial services | 2003 |
| Financial Life Planning Limited | Financial services | 2014 |
| Financial Performance Group Ltd | Financial services | 2023 |
| Financial Planning Business Limited | Financial services | 2012 |
| Financial Power Limited | Financial services | 2012 |
| Financial Regulation Courses Ltd | Education | 2023 |
| Financial Renaissance Ltd | Financial services | 2018 |
| Financial Super Systems Ltd | Information & communication | 2016 |
| Financial Technology Academy Ltd | Professional & scientific | 2024 |
| Financial VUE Limited | Financial services | 2017 |
| Financial Wellness Ltd | Education | 2020 |
| Financial Wisdom Ltd | Information & communication | 2021 |
| Finanzpraxis AG | Administrative & support | 2020 |
| Finbello Ltd | Professional & scientific | 2016 |
| Finberg Marketing Ltd | Administrative & support | 2022 |
| Finblocks Nominees Limited | Other services | 2019 |
| Finbot Technologies Limited | Information & communication | 2018 |
| Finch Creative Wellbeing CIC | Education | 2026 |
| Finchleyfinds Limited | Wholesale & retail | 2025 |
| Finclusion Systems Ltd | Information & communication | 2015 |
| Finco Coffee Ltd | Manufacturing | 2018 |