Calendar Year Filers (Most Common) File on: April 15 Fiscal Year Filers File on: The fourth month after your fiscal year ends, day 15. If your due date falls on a Saturday, Sunday, or legal holiday, the due date is delayed until the next business day. Your return is considered filed on time if the envelope is properly addressed, postmarked, and deposited in the mail by the due date. Need More Time? If you can’t file by the due date of your return, you should request an extension of time to file. To receive an automatic 6-month extension of time to file your return, you must file Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return by the due date of your return. An extension of time to file is not an extension of time to pay. You may be subject to a late payment penalty on any tax not paid by the original due date of your return. Members of the Military Special rules may apply if you served or are serving in the Armed Forces in a combat zone or a contingency operation, or become hospitalized resulting from an injury received while serving in such an area or operation. You generally have at least 180 days after you leave the designated combat zone/contingency operation to file and pay taxes. If the Service determines you to be affected by a presidentially declared disaster or a terroristic or military action, you may have up to one year after the due date of your return to file and pay taxes, depending on the deadline specified by the Service.