Oklahoma Nonprofit Tax Deadlines 2026
Complete guide to Nonprofit filing dates, extensions, estimated payment schedules, and required forms in Oklahoma for the 2026 tax year. Oklahoma imposes a state income tax, so Nonprofit entities must file both federal and state returns.
Oklahoma Nonprofit filing deadline
Nonprofit annual return generally due the 15th day of the 5th month.
Due: May 15, 2026
Extension: Nov 15, 2026
Form: State nonprofit return
Estimated payments
No state estimated payment schedule listed.
Due: N/A
Oklahoma Nonprofit Tax Calendar at a Glance
| Event | Date |
|---|---|
| Filing deadline | May 15, 2026 |
| Extension deadline | Nov 15, 2026 |
FAQ
When is the Nonprofit tax filing deadline in Oklahoma for 2026?
The Oklahoma Nonprofit tax return is due May 15, 2026 for the 2026 tax year. An extension is available until Nov 15, 2026.
Does Oklahoma require Nonprofit estimated tax payments?
Estimated payments are not typically required at the entity level for Nonprofit in Oklahoma, but confirm with Oklahoma Tax Commission.
What form do I file for a Nonprofit in Oklahoma?
Nonprofit entities in Oklahoma file using Form State nonprofit return. You can download the form from Oklahoma Tax Commission at https://oklahoma.gov/tax.html.
Can I get an extension for my Oklahoma Nonprofit tax return?
Yes. Oklahoma allows an extension for Nonprofit returns until Nov 15, 2026. Note that an extension gives you more time to file, not more time to pay — any tax owed is still due by the original deadline of May 15, 2026.
What are the penalties for filing late in Oklahoma?
Oklahoma typically charges a failure-to-file penalty (usually 5% of unpaid tax per month, up to 25%) and a failure-to-pay penalty (usually 0.5-1% per month). Interest also accrues on unpaid balances. Filing for an extension by the original deadline avoids the failure-to-file penalty but not the failure-to-pay penalty.
Where can I file Oklahoma Nonprofit taxes?
File through Oklahoma Tax Commission. Visit https://oklahoma.gov/tax.html for e-filing options, downloadable forms, and payment portals.
Oklahoma Estimated Tax Payments
View the full quarterly estimated payment schedule for Oklahoma, including all entity types and payment methods.
View Oklahoma estimated payments →