Paying Taxes and Obtaining Refunds Except when a bond or an employer letter is furnished, or the IRSis satisfied that your departure does not jeopardize the collection ofincome tax, you must pay all tax shown as due on the Form 1040-Cat the time of filing it. If the tax computation on Form 1040-Cresults in an overpayment, there is no tax to pay at the time you filethat return. However, the IRS cannot provide a refund at the time ofdeparture. If you are due a refund, you must file either Form 1040NRor Form 1040NR-EZ at the end of the tax year.