In years past, unanswered calls that went toVM were billed for a "round-trip" call. That is, once charge for a call to the country where your phone last registered on a network, and another minute call for the unanswered call to be picked up by VM. This was the case on most (all?) GSM systems when roaming.
I rarely ran into this because I would hard forward all calls to VM when overseas. When wifi calling came to TM, I would wait until got to hotel or a place w. wifi to deal with calls. I would shut off all data use except email - which was covered by BB unlimited email option.
Now, on our last trip could leave phone on all the time because of the new free data and SMS that is now included.
QUESTION - should we hard forward all incoming calls to VM when we turn off the phones at nite to avoid extra charges? IOW, are we charged for unanswered calls that go to VM?