You just touch the symbol at the bottom left of your Nav screen. This opens other options up the left-hand side. Touch the top symbol on the left which opens a section across the top of the page. Enter your required post code there then touch it and you will be asked if you want to start. Only trouble is that it will not store postcodes for future reference, just co-ordinates. Have checked storage problem with local service manager and he confirms this is a failure in the software design. The other thing which can be disconcerting is the pronunciation of street names as you are directed - most are very weird foreign pronounciations bearing little relationship to the way we say them.