| FluidOne | Greater London |
| FluoretiQ | |
| Flusso Ltd | |
| Flutter Developers | |
| Flutter Entertainment plc | |
| Fly Now Pay Later Ltd | |
| Fly On The Wire | Dundee |
| Fly Software Ltd | |
| FlyByte | |
| Flyford Connect Ltd | Lincolnshire |
| Flying Frog Consultancy Ltd | Cambridgeshire |
| Flylogix Holdings Ltd | |
| Flywhel IT Services | |
| FM Retail | Oxfordshire |
| FMA Systems Ltd | Oxfordshire |
| FMIS Ltd | Kent |
| Fnality International | |
| FNZ (UK) Ltd | |
| Focal Exhibitions | |
| Focal Point Positioning Ltd | |
| Focaldata | |
| Focalpoint Digital Ltd | |
| Focus Agency Group | |
| Focus Digital Ltd | |
| Focus Educational Software Ltd | Cornwall |
| Focus Group | Kent |
| Focus IMC | Essex |
| Focus Legal Solutions Ltd | |
| Focus Solutions | Warwickshire |
| Focus Technology | |
| Focused All Day | |
| Folding Space | |
| Folium Science | |
| Fomcap Ltd | |
| Fome Agency | |
| Fondue Web Solutions | Leicestershire |
| Fondy | |
| Fonefunshop Ltd | South Yorkshire |
| Fonehouse | Berkshire |
| FonFix4U | |
| Fontware Ltd | Hampshire |
| Food and Drink Technology | |
| Food Tech Matters | |
| Foodbud Ltd | |
| FOODt Ltd | Greater London |
| Foonkie Monkey | |
| Foonkie Monkey | |
| Footprint Digital | |
| Footsteps Design Ltd | Essex |
| Fora Space Ltd | |