| FO Southampton Ltd | Arts & recreation | 2015 |
| Foil Events Ltd | Hospitality | 2022 |
| Fold Audio Ltd | Information & communication | 2023 |
| Follow the Path Ltd | Professional & scientific | 2025 |
| Fontein London Limited | Health & social care | 2022 |
| Food Matters Limited | Other services | 2012 |
| Football for Future CIC | Education | 2021 |
| Footgolf FA Limited | Arts & recreation | 2018 |
| Footsteps Ltd Limited | Other services | 2015 |
| Forbes Retail Consultancy Limited | Administrative & support | 2012 |
| Force 1 Construction Limited | Construction | 2019 |
| Forest Farm Yard Management Company Limited | Extraterritorial | 2013 |
| Forest ROW Worthing Ltd | Wholesale & retail | 2023 |
| Forge Design Consultancy Ltd | Professional & scientific | 2016 |
| Forge House Services Limited | Health & social care | 2006 |
| Forgeukbio Ltd | Wholesale & retail | 2026 |
| Foricons Ltd | Other services | 2020 |
| Fork Andles Gardening Services Ltd | Administrative & support | 2017 |
| Formalmutual Property Management Limited | Households | 1998 |
| Format Films Ltd | Information & communication | 2003 |
| Fortico Interior Ltd | Construction | 2026 |
| Fortuna Holding Home Design Ltd | Other services | 2020 |
| Fortune Diner Limited | Hospitality | 2022 |
| Forward Elevation Limited | Professional & scientific | 2020 |
| Forward Horticulture Consulting Limited | Professional & scientific | 2012 |
| Forward Pass Football Academy Ltd | Education | 2015 |
| Forward Properties Limited | Administrative & support | 1997 |
| Fotoura Ltd | Information & communication | 2011 |
| Foundlight Productions Limited | Information & communication | 2018 |
| Fountain House London Limited | Hospitality | 2025 |
| Fountech AI UK Limited | Professional & scientific | 2019 |
| Four Corners London Limited | Professional & scientific | 2019 |
| Four Dogs and a Fish Productions Ltd | Information & communication | 2023 |
| Four Seasons Garden Preparation & Garden Maintenance Limited | Administrative & support | 2016 |
| Fourteen Street Limited | Information & communication | 2024 |
| FOX & Finch (Worthing) Ltd | Hospitality | 2023 |
| FOX and Crow Consultancy Ltd | Professional & scientific | 2016 |
| Foxak Ltd | Information & communication | 2023 |
| Foxford Vineyard LLP | | 2024 |
| Foxglove Research Limited | Other services | 2025 |
| Foxiferous Ltd | Information & communication | 2018 |
| Foxo Ltd | Hospitality | 2026 |
| Fozart Limited | Administrative & support | 2003 |
| FP Property Sussex Ltd | Real estate | 2017 |
| FP Sussex Ltd | Construction | 2014 |
| FR VG Ltd | Wholesale & retail | 2025 |
| Fracture Reality Ltd | Information & communication | 2016 |
| France Terroir Limited | Wholesale & retail | 2012 |
| Francelli Media Limited | Information & communication | 2022 |
| Franchesqa Limited | Wholesale & retail | 2025 |
| Francis Building Ltd | Construction | 2024 |
| Francis Coastal Construction Ltd | Construction | 2023 |
| Francis Homes Sussex Ltd | Construction | 2022 |
| Francis MAY Group Ltd | Information & communication | 2018 |
| Francome House Freehold Owners Company Limited | Households | 1978 |
| Franklin Field Ltd | Construction | 2023 |
| Frantic Fish Ltd | Information & communication | 2009 |
| Frasier Morgan Ltd | Professional & scientific | 2005 |
| Freckle Limited | Arts & recreation | 2015 |
| Freda Coffee Ltd | Wholesale & retail | 2026 |
| Freddie FOX International (UK) Limited | Wholesale & retail | 2005 |
| Frederica Trading Limited | Other services | 2012 |
| Free Limited | Wholesale & retail | 1986 |
| Freedom of Speech Limited | Administrative & support | 2006 |
| Freedom Speech Limited | Professional & scientific | 2021 |
| Freedom Works Ltd | Administrative & support | 2016 |
| Freedom World Limited | Transport & logistics | 2019 |
| Freefarm Limited | Arts & recreation | 2008 |
| Freehold English Land Agency Limited | Real estate | 2005 |
| Freemans Close Homes Ltd | Construction | 2025 |
| Freestone Consultants Limited | Extraterritorial | 2003 |
| Freestyle Kitchen Studio Limited | Manufacturing | 2007 |
| FREIGHT-365 Limited | Transport & logistics | 2014 |
| Frelia Global Ltd | Wholesale & retail | 2023 |
| Frelia Living Ltd | Real estate | 2025 |
| Frelia Properties Ltd | Real estate | 2023 |
| French Holdings Limited | Financial services | 2021 |
| Frensy Ltd | Information & communication | 2026 |
| Frescade Properties Limited | Construction | 2022 |
| Fresh & UP Ltd | Other services | 2022 |
| Fresh Architects Ltd | Professional & scientific | 2020 |
| Fresh Catering & Events Limited | Hospitality | 2016 |
| Fresh Consultants Ltd | Professional & scientific | 2024 |
| Fresh EGG Group Limited | Professional & scientific | 2025 |
| Fresh EGG Limited | Information & communication | 2000 |
| Fresh Holdings Ltd | Real estate | 2025 |
| Fresh Start Social Enterprise CIC | Wholesale & retail | 2023 |
| Freshwater Fish Finder Ltd | Agriculture & fishing | 2025 |
| Freyr Investment Management Limited | Financial services | 2024 |
| Friday Puzzle Club Ltd | Wholesale & retail | 2026 |
| Friday's Child Productions Limited | Information & communication | 2024 |
| Friends From Work Ltd | Information & communication | 2026 |
| Friesian Developments Holdings Limited | Financial services | 2025 |
| Friesian Developments Limited | Real estate | 2019 |
| Friesian Trading Limited | Construction | 2020 |
| Frithspear Limited | Households | 1978 |
| Frogalina Ltd | Information & communication | 2019 |
| Fromagerie Beillevaire UK Limited | Wholesale & retail | 2010 |
| Fronima Care Ltd | Health & social care | 2025 |
| Front 2 Back Records Limited | Arts & recreation | 2003 |