If you choose to take a debit or check card with you overseas, make sure the card has either a Visa or Mastercard symbol on it. If not, it may be a simple ATM card and not recognized by foreign machines, thus rendering it unusable. Before you leave, double-check with your bank that your card will be valid abroad. Sometimes personal identification numbers may change overseas and you will have to be assigned a new one. You may need to arrange to have tax forms sent to you or have your taxes taken care of during your absence.
Tax forms are usually available at U.S. consulates or embassies.
It is very possible to ask for an extension. Be sure to know what your tax responsibilities are and how to comply while you are out of the country. The Office of International Programs is neither qualified nor experienced to give legal tax advice. If you have any questions about filing your taxes, consult with a tax expert.