Tax Extension Deadline Guide for Late Filing (2026)
File tax extension: Form 4868, deadline extension, payment requirements, and late filing penalty avoidance.
Summary
Extension grants extra time to file. This guide explains Form 4868, deadlines, and payment requirements.
Key Steps
- 1File Form 4868: automatic 6-month extension to October 15.
- 2Extension for filing only: estimated tax still due by April 15.
- 3Pay estimated tax: pay 90% of expected liability by April 15.
- 4Avoid late payment penalty: unpaid tax after April 15 accrues interest.
- 5File by October 15: extension expires, late filing penalty after.