If you owe taxes, but can't pay in full by the April deadline, you should file your federal tax return anyway and pay as much as possible to reduce penalty and interest amounts. An extension of time to file is not an extension of time to pay your taxes. To out find more information about how to pay your taxes visit IRS.gov/payments. Pay as much as you can by the original due date - usually in April. Then you can set up a payment plan to pay the rest of the balance you owe along with the interest and penalties. Remember, visit irs.gov/payments for more info.