A valid extension to file a federal return automatically extends the due date of the Oklahoma return if no Oklahoma liability is owed. Enclose a copy of the federal extension with the Oklahoma return. If the federal return is not extended or Oklahoma tax is owed, file Form 504-I, Application for Extension of Time to File an Oklahoma Income Tax Return for Individuals, to request an extension to October 15. An extension is valid and a late-payment penalty may be avoided only if 90% of the tax liability is paid by the original due date. Interest will be charged from the original due date of the return.
To access the Oklahoma Form 504-1, from the main menu of the Oklahoma state return select:
- Oklahoma Extension of Time To File
- Enter Extension
Note: Electronic filing is not supported for the state extension. The federal extension payment may be sent electronically, however the state extension will have to be mailed.
Additional Information:
Oklahoma State Tax Information
Where Do I Set Up Estimated Payments for Oklahoma?