Personal income tax penalties
Oregon doesn't allow an extension of time to pay even if the IRS allows an extension.
You will owe a 5 percent late-payment penalty on any Oregon tax not paid by the original due date of the return, even if you have filed an extension.
If you file more than three months after the due date (including extensions), a 20 percent late-filing penalty will be added; so, you will owe a total penalty of 25 percent of any tax not paid. A 100 percent penalty is also charged if you do not file a return for three consecutive years by the due date of the third year, including extensions. In some situations additional penalties may be added. Read more in Publication OR-17.