When filing the last few days of tax season when millions of filers who owe are jamming the system it can take a week or 2 for the feds or state to catch up with all the payments requested ... as long as you were filed and accepted by 4/15 and the payment request was for that date or prior then you are fine. If you get a notice for late fees respond then send proof of timely filing and the payment request to refute the bill.
