The moderator moved your other similar post on Korea, Hong Kong, Taiwan, Indonesia to this forum. I posted an answer there. If your phone is on the plan we are talking about here, you are covered. You won't need to do anything for international data. Make sure we are talking about INTERNATIONAL unlimited data plan, not just its domestic counterpart. You'll be paying $64.99 a month for your data (or $69.99 a month if you were on a data only plan with no voice service). Obviously you can't legally tether on this plan.