Connecticut Nonprofit Tax Deadlines 2026

Complete guide to Nonprofit filing dates, extensions, estimated payment schedules, and required forms in Connecticut for the 2026 tax year. Connecticut imposes a state income tax, so Nonprofit entities must file both federal and state returns.

Connecticut Nonprofit filing deadline

Nonprofit annual return generally due the 15th day of the 5th month.

On Track

Due: May 15, 2026

Extension: Nov 15, 2026

Form: State nonprofit return

Estimated payments

No state estimated payment schedule listed.

N/A

Due: N/A

Connecticut Nonprofit Tax Calendar at a Glance

EventDate
Filing deadlineMay 15, 2026
Extension deadlineNov 15, 2026

FAQ

When is the Nonprofit tax filing deadline in Connecticut for 2026?

The Connecticut Nonprofit tax return is due May 15, 2026 for the 2026 tax year. An extension is available until Nov 15, 2026.

Does Connecticut require Nonprofit estimated tax payments?

Estimated payments are not typically required at the entity level for Nonprofit in Connecticut, but confirm with Connecticut Department of Revenue Services.

What form do I file for a Nonprofit in Connecticut?

Nonprofit entities in Connecticut file using Form State nonprofit return. You can download the form from Connecticut Department of Revenue Services at https://portal.ct.gov/DRS.

Can I get an extension for my Connecticut Nonprofit tax return?

Yes. Connecticut 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 Connecticut?

Connecticut 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 Connecticut Nonprofit taxes?

File through Connecticut Department of Revenue Services. Visit https://portal.ct.gov/DRS for e-filing options, downloadable forms, and payment portals.

Connecticut Estimated Tax Payments

View the full quarterly estimated payment schedule for Connecticut, including all entity types and payment methods.

View Connecticut estimated payments →

Other Entity Types in Connecticut

Nonprofit Deadlines in Neighboring States