| Faxtastic Ltd | Bedfordshire |
| Fayre Labs Ltd | Greater London |
| FCA Innovation | |
| fDi Intelligence | |
| FDI Technology | Essex |
| FDP | West Yorkshire |
| FE fundinfo Ltd | |
| Feabhas Ltd | Wiltshire |
| Fear of Mice | Devon |
| Featurespace Ltd | Cambridgeshire |
| Fecking Creative | |
| Federation Against Software Theft Ltd | Berkshire |
| Federation of Communication Services | |
| Federation of European Biochemical Societies | |
| Feedback Instruments Ltd | |
| FeedBear | |
| Feedespy Ltd | |
| FeedForward | |
| Feedr | Greater London |
| Feefo | |
| Feefo Holdings Ltd | Hampshire |
| Feisty Duck | |
| Felinesoft | |
| Felix Capital | |
| Fellow Studio Ltd | |
| Felltech Ltd | Cambridgeshire |
| Female Invest | |
| FemTech Annalytics | |
| Femtech Insider Ltd | |
| FemTechLab | |
| Fennex | |
| Fenti Ltd | |
| Fentons Business IT Services | West Sussex |
| Fera Science Ltd | |
| Fernhall Associates Ltd | Bristol |
| Ferns IT Consultancy Ltd | |
| Fertifa Ltd | |
| Fertile Frog Ltd | |
| Fetch.ai | Cambridgeshire |
| Fetch.ai | |
| FeverFive | |
| FeynLabs.AI | |
| FFEI | Hertfordshire |
| FFWD London | |
| FG Burnett | |
| FG Design | Dorset |
| FGreeClix Ltd | Norfolk |
| Fhoke | |
| Fiasco Design | |
| Fiber Optic UK Ltd | |