When filing for an Oklahoma state tax extension, you are requesting additional time to file your Oklahoma resident income tax return (Form 511) without incurring penalties for late filing. However, it is important to note that an extension only grants more time to file — not to pay. If you owe tax, you must still pay at least 90% of your total liability by the original due date to avoid a delinquent penalty of 5%.
When to Use Form 504-I
- Use Form 504-I to request an Oklahoma individual income tax filing extension when you owe additional Oklahoma tax or do not have a federal extension.
- Oklahoma generally honors an automatic federal extension when no additional Oklahoma tax is due.
- If additional Oklahoma tax is due, Form 504-I should be used, and at least 90% of the total Oklahoma tax liability must be paid by the original due date. Oklahoma will not grant the extension without this payment.
Key Rules for Oklahoma Tax Extensions
- An extension provides additional time to file, not to pay.
- A 5% delinquent penalty may apply if at least 90% of the tax liability has not been paid by the original due date.
- Interest of 1.25% per month may apply to unpaid tax from the original due date until paid.
How to Make a Payment
- An electronic payment is accepted for an extension payment at oktap.tax.ok.gov. There is a convenience fee charged for utilizing some of the electronic payment services.
- Retain the confirmation number for your records.
- If you make your extension payment electronically, do not mail Form 504-I. When you file your income tax return, provide a copy of Form 504-I.
To Mail - Mail Form 504-I with payment, if applicable, to:
Oklahoma Tax Commission
PO Box 26890
Oklahoma City, OK 73126-089
How to File an Extension Using Software
- Select the current tax year and click “View My Extension Return.”
- On the “FORM 4868: EXTENSION” page, scroll to the bottom and click “File State Extension.”
- Select Oklahoma and click “Revisit” to follow on-screen instructions for completing the state extension filing.
Source:
Form 504-I: Application for Extension of Time to File Oklahoma Individual Income Tax Return
Form 511: Oklahoma Resident Income Tax Return
Disclaimer: Always verify details with the official Oklahoma Tax Commission forms and instructions. For complex situations, consult a CPA or tax professional.