Connecticut LLC Tax Deadlines 2026

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

The Connecticut LLC tax return is due Mar 16, 2026 for the 2026 tax year. An extension is available until Sep 15, 2026.

Does Connecticut require LLC estimated tax payments?

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

What form do I file for a LLC in Connecticut?

LLC entities in Connecticut file using Form State business income tax 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 LLC tax return?

Yes. Connecticut allows an extension for LLC returns until Sep 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 Mar 16, 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 LLC taxes?

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