What is considered “timely” with regard to mailing a check for payment and e-filing the return?
Both the return and the payment are due on or before the due date. Electronic payment transactions must be submitted prior to 4 p.m. on the due date in order to be considered timely. Paper payments must be postmarked on or before the due date. If the due date falls on a weekend or a holiday, the due date is the next business day.
