I bought the US T-mobile prepaid SIM card while I stayed in the US and now it expired. I would like to keep using my card when I visit the US this month again. Can I top up my account from outside of theUS or how should I do? If possible, I would like to start using my phone when I get arrive at the US as soon as possible.
What do you mean by, expired? If you have just ran out of funds with your prepaid balance recently, then topping up shouldn't be an issue. If it has been more than a few months since you ran out of funds and topped up, then the SIM will more than likely be deactivated. If the SIM is deactivated, then you will need a new SIM.