Here's the situation: My parents have an unlocked 4 with T-Mobile on a non-contract, month to month plan. They live in the U.S. 6-7 months out of the year and travel and reside in another country the remainder. T-Mobile's stipulation is, if the sim/cell number is not reloaded within 2 months time, they loose that number and would therefore have to renew their plan all over again with a new sim from T-Mobile and be issued a new number. The issue here is, my parents, would have to notify their family and friends with their new number every year. My questions is, can they use google voice and offer that number to family and friends without ever forfeiting the number when they travel 5-6 months out of the year and not reload their T-Mobile sim during the time they're outside the U.S, so that their family and friends can contact them. Of course, they'd be on an international sim, in whichever, country they'll be in. What's the best solution? Thanks!