Sometimes the IRS may not be able to debit your payment until after the deadline, due to high e-filing volume. In addition, it can take your bank another few days to post the debit to your account.

No worries; as long as you filed your return or extension on or before April 18, 2017 and you selected April 18, 2017 (or earlier) as your payment date, you won't get penalized for late payment.

call IRS e-file Payment Services at 1-888-353-4537 or contact your state tax agency, as appropriate.