Originally Posted by
ajGoes
Should I use another Google account for my Fi number, or is it easy to cancel Fi altogether and revert to Voice?
Cancelling Fi and going back to GV involves actually porting the number back to a different provider, even though both are controlled by Google. I would definitely recommend setting up Fi on a separate Google account so you can pause and resume it as necessary without messing around with your 'real' GV number. I had Fi on my 'real' number a few years back and it took them four days to port the number back to GV.
Originally Posted by
Bandicoot
One thing to note, if you cancel your Fi service, Google does not promise you that your old Google Voice number will be available for you to go back to. (Even if that is the number that you ported from Google Voice to Project Fi.)
This is real, but it's rare--there are a few GV numbers that are 'from' places where bandwidth.com no longer has blocks of numbers. Numbers from big cities are more or less immune to this. Far more common is the situation where Fi assigns a new number from T-Mobile's space but you can't take that to GV because bandwidth.com doesn't exist there.