Key Takeaways

  • The standard filing deadline for Form 1040 is April 15 (or the next business day if it falls on a weekend or holiday)
  • Form 4868 provides an automatic 6-month extension to file until October 15, but taxes owed are still due by April 15
  • U.S. citizens and residents living abroad get an automatic 2-month extension to June 15 without filing any form
  • Combat zone personnel receive 180 days after leaving the combat zone plus the number of days remaining until April 15 when they entered
  • Disaster area taxpayers receive automatic extensions for both filing AND payment, with dates announced by the IRS
Last updated: January 2026

Filing Deadlines & Extensions

Every tax professional must master the rules governing when returns are due and how to properly extend filing deadlines. This is frequently tested on the EA exam because it directly impacts your day-to-day work with clients.

Standard Filing Deadline: April 15

The Form 1040 is due on the 15th day of the 4th month following the end of the tax year. For calendar year taxpayers, this means April 15 of the following year.

Weekend and Holiday Rule: If April 15 falls on a Saturday, Sunday, or legal holiday, the deadline moves to the next business day.

For the 2024 tax year (tested on the EA exam May 2025 - February 2026), returns are due April 15, 2025.

The Automatic 6-Month Extension (Form 4868)

Taxpayers who need more time to file can request an automatic extension using Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return.

Form 4868 Key PointsDetails
Extension Length6 months (April 15 to October 15)
Reason Required?No - extension is automatic
How to FileElectronically (IRS Free File, tax software) or by mail
Deadline to RequestMust be filed by April 15
Payment Required?Should estimate and pay any tax owed

Critical Exam Point: Filing Form 4868 extends your time to file the return. It does NOT extend your time to pay any tax owed. If you owe taxes and do not pay by April 15, you will be subject to failure-to-pay penalties and interest, even if you filed for an extension.

How to File Form 4868

There are three primary ways to request an extension:

  1. IRS Free File - Available to all taxpayers at IRS.gov, regardless of income
  2. Electronic Filing - Through tax preparation software or a tax professional
  3. Paper Filing - Mail Form 4868 to the IRS (must be postmarked by April 15)

Payment Tip: If you make an electronic payment and select "extension" as the payment type, you receive confirmation and do not need to file a separate Form 4868.

Estimated Tax Payment with Extension

When filing Form 4868, you must estimate your total tax liability for the year. If you expect to owe additional tax:

  • Pay at least 90% of the tax due to avoid the failure-to-pay penalty
  • Any remaining balance paid by October 15 will not incur failure-to-pay penalties (though interest still applies)

If you significantly underestimate your tax liability, you may face underpayment penalties under IRC Section 6654.


Special Extension Categories

Taxpayers Outside the United States

U.S. citizens and resident aliens whose tax home and abode are outside the United States and Puerto Rico on April 15 receive an automatic 2-month extension to file and pay.

Outside U.S. ExtensionDetails
New Filing DeadlineJune 15 (or next business day)
Form Required?No - automatic if you qualify
Payment Extension?Yes, but interest accrues from April 15
Additional Extension?Can file Form 4868 by June 15 for 4 more months (to October 15)

Important Distinction: This applies only if you are living abroad with your main place of business or post of duty outside the U.S. Simply traveling on vacation or a business trip on April 15 does NOT qualify.

Combat Zone Extensions

Military personnel serving in a designated combat zone receive generous deadline extensions for filing and paying taxes. This also applies to:

  • Civilian support personnel
  • Military contractors
  • Press correspondents working in combat zones

Combat Zone Extension Calculation:

ComponentHow It Works
Base Extension180 days after leaving the combat zone
PlusDays remaining until April 15 when entering the zone
Applies ToFiling, paying, and most IRS actions

Example: A soldier enters a combat zone on February 1. He leaves on March 31 of the following year. His extension equals:

  • 180 days from March 31
  • Plus 74 days (February 1 through April 15)
  • Total: 254 days from March 31

Disaster Area Extensions

When the President declares a federal disaster area, the IRS provides automatic extensions for affected taxpayers:

Disaster ReliefDetails
Filing ExtensionYes - automatic
Payment ExtensionYes - automatic (no penalties or interest)
Form Required?No - IRS identifies affected areas automatically
Who QualifiesResidents, businesses, and relief workers in the disaster area

The IRS announces specific deadline extensions for each disaster. These can vary from a few weeks to several months.

Key for Exam: Unlike Form 4868 extensions, disaster area extensions provide relief from both filing AND payment penalties.


Summary: Extension Types at a Glance

SituationFiling DeadlinePayment DeadlineForm Required
Standard (no extension)April 15April 15None
Form 4868 ExtensionOctober 15April 15Form 4868
Living AbroadJune 15June 15 (interest from April 15)None
Living Abroad + Form 4868October 15June 15 (interest from April 15)Form 4868 by June 15
Combat Zone180 days + remaining daysSame as filingNone
Disaster AreaIRS announced dateSame as filingNone
Test Your Knowledge

A taxpayer files Form 4868 on April 14, estimating she owes $2,000 in additional taxes. She pays nothing with the extension and files her return on September 15, paying the full $2,000 owed. Which of the following is TRUE?

A
B
C
D
Test Your Knowledge

Maria is a U.S. citizen living and working in Germany. Her main place of business is in Berlin. On April 15, when is her tax return due WITHOUT filing any extension form?

A
B
C
D
Test Your Knowledge

A soldier enters a designated combat zone on February 1 and remains there until March 1 of the following year. How is her filing extension calculated?

A
B
C
D