An extension extends the time you have to file your return by up to 5 months. If you need to pay taxes, you are required to pay the amount due by May 17, 2021.
If you pay late, you may be charged a late penalty and interest on any unpaid taxes.
Estimate your total tax and pay the amount you owe electronically, by check or credit or debit card.
To avoid a late filing penalty, you must file your return by October 15, 2021.