I’ve been using Google Voice for eons — starting before Google acquired GrandCentral. It saved me thousands on my daily mobile calls to my mother in Canada.
GV must be a real money loser for Google though — the interconnect fees to landlines are a real cost . So it’s not surprising that it’s a bit of a mess — between GV legacy, GV current, Hangouts  and heaven knows what else.
Today I tried a GV call from my iPhone and got “We could not complete your call - Please try again.” In my case this is a bug that happened because the GV number associated with the Google ID I was using did not have an associated mobile phone (I’d moved that phone to a different GV account). I think Google Voice.app for iOS used to permit that, but it doesn’t now. To use Google Voice.app now you need to have an associated verified mobile phone with the active GV account.
So I moved my two mobile numbers to the two GV accounts I wanted them on. Now if I try to use Google Voice.app with an account that doesn’t have a verified mobile number it gives me a more appropriate error message (that’s why this was a bug — wrong error message).
I’d be happy if GV would figure a way to make money from me, it is a great service.
- fn -
 Funny thing and cautionary tale: In the early 90s we were sure that by the year 2000 voice calls would be so cheap they wouldn’t be worth metering. That was only sort of true. Never underestimate the power of discontinuities.
 GV sort-of migrated to Hangouts, but that seems to have stalled and perhaps reversed. Hangouts seems to be dying, caught up in Google’s flailing messaging strategy.