When is my Oklahoma tax return due?

Generally, your Oklahoma income tax return is due April 15th. However:

• If you e-file (through a preparer or the internet), your due date is extended to April 20th. Any taxes due on April 20th must be paid electronically (by direct debit, etc.) in order to be considered on time. If the balance due on an e-filed return is not paid electronically, penalty and interest will accrue from the original due date.
• If the due date falls on a weekend or legal holiday when the Oklahoma Tax Commission offices are closed, your return is due the next business day. Your return must be postmarked by the due date to be considered timely filed.
• If the Internal Revenue Code (IRC) of the IRS provides for a later due date, your return may be filed by the later due date and will be considered timely filed. You should write the appropriate "disaster designation" as determined by the IRS at the top of the return, if applicable. If a bill is received for delinquent penalty and interest, you should contact the OTC at the number on the bill.