Upvote:2
They do expire in about six months to a year. I have asked Movistar repeatedly about this but the answers were all over the place. Last card I bought I didn't use from Jan 10 to July 20, and it still worked; I think, though, that I recharged it remotely before the six months would kick in by July 10.
Other Movistar cards that I didn't use for a longer time were deactivated before a year. On the "interesting" side, even after the sim was no longer active and the number had been given to another user, I was still able to see the call logs on Movistar's page. Talk about bad IT (not that I expect the other carriers to be better at this).
As for roaming, it didn't roam in Canada nor in Chile, so I assume it doesn't anywhere.