Federal taxes can be filed starting in late January, once the IRS opens its filing season, and the return is due by April 15 for most individuals. The 2026 filing season opened on January 26, 2026, for tax year 2025 returns.1Internal Revenue Service. IRS Opens 2026 Filing Season If you need more time, an automatic six-month extension pushes your filing deadline to October 15, though it does not extend the time to pay.
When the IRS Starts Accepting Returns
The IRS sets a specific date each January when it begins accepting and processing returns. For tax year 2025 returns, that date was January 26, 2026.1Internal Revenue Service. IRS Opens 2026 Filing Season Tax software lets you prepare a return earlier, but it will sit in a queue until the season officially opens.
There is a practical reason not to rush. Employers have until January 31 to send out W-2s, and banks and brokerages work on similar deadlines for 1099 forms. Many people do not have every document in hand until early February. Filing with missing or wrong income figures leads to IRS notices and amended returns, so waiting a few extra days for the paperwork to show up is usually worth it.
The April 15 Filing Deadline
Federal law sets the due date for individual income tax returns as the fifteenth day of the fourth month after the tax year ends, which falls on April 15 for anyone on a calendar year.2Office of the Law Revision Counsel. 26 USC 6072 – Time for Filing Income Tax Returns In 2026, April 15 lands on a Wednesday, so no adjustment applies.
In other years the date can shift. When April 15 falls on a Saturday, Sunday, or legal holiday, the deadline rolls to the next business day. The tax code treats holidays observed in Washington, D.C., as legal holidays for this purpose, which is how the D.C.-specific Emancipation Day on April 16 has pushed the national deadline to April 17 or 18 in some past years.3Office of the Law Revision Counsel. 26 USC 7503 – Time for Performance of Acts Where Last Day Falls on Saturday, Sunday, or Legal Holiday
If you mail a paper return, the postmark date controls whether you filed on time, not the date the IRS receives it. Certified mail creates a legal record of that postmark, which matters if the agency later questions whether you filed by the deadline.4Office of the Law Revision Counsel. 26 USC 7502 – Timely Mailing Treated as Timely Filing and Paying
Getting More Time: The Six-Month Extension
If April 15 is going to come and go before your return is ready, filing Form 4868 gives you an automatic six-month extension, moving the filing deadline to October 15.5eCFR. 26 CFR 1.6081-4 – Automatic Extension of Time for Filing Individual Income Tax Return No explanation is required.
The catch sits at the heart of the extension process, and it trips people up every year: an extension gives you more time to file paperwork, not more time to pay. Any tax you owe is still due on April 15. If you miss that payment date, interest and penalties start running on the unpaid balance even though your filing deadline has moved.
The workaround is to estimate what you owe and send that amount with Form 4868. The IRS will not charge the underpayment penalty if you have paid at least 90% of your actual liability by the original April deadline.
Automatic Extra Time for Certain Taxpayers
Some taxpayers get additional time without filing anything.
Living Abroad
If both your tax home and your main residence are outside the United States and Puerto Rico, you receive an automatic two-month extension to June 15.6eCFR. 26 CFR 1.6081-5 – Extensions of Time in the Case of Certain Partnerships, Corporations and U.S. Citizens and Residents This one covers both filing and paying. You can still file Form 4868 on top of it before June 15 for an additional four months, moving your filing deadline to October 15.
Combat Zone Service
Service members deployed to designated combat zones have their filing, payment, and other tax deadlines suspended for the entire period of service in the zone, plus 180 days after they leave.7Internal Revenue Service. Extension of Deadlines – Combat Zone Service The IRS coordinates with the Department of Defense to identify qualifying taxpayers and automatically pause audits and collections during deployment.
Federally Declared Disaster Areas
When the IRS grants disaster relief, filing and payment deadlines in the affected area are postponed. The new dates vary by disaster and are published through IRS news releases. If your address of record is in a covered area, the relief usually applies automatically without any filing on your part.
What Late Filing or Late Payment Costs
Two separate penalties can hit a late return, and the one for not filing is far bigger than the one for not paying.
The failure-to-file penalty is 5% of your unpaid tax for each month the return is late, capped at 25%. If you file more than 60 days after the deadline, the minimum penalty is the lesser of $435 or 100% of what you owe.8Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax
The failure-to-pay penalty is 0.5% of the unpaid amount per month, also capped at 25%.8Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax On top of that, the IRS charges interest on the unpaid balance. The rate for the first quarter of 2026 is 7% per year, compounded daily; for the second quarter it drops to 6%.9Internal Revenue Service. Quarterly Interest Rates
When both penalties apply in the same month, the failure-to-file charge is reduced by the failure-to-pay amount, so the combined hit is not a flat 5.5%. Even so, the arithmetic strongly favors filing on time. If you cannot pay, file anyway: it removes the much larger 5%-per-month charge entirely.
Quarterly Deadlines for Estimated Taxes
If you are self-employed, earn significant investment income, or receive other money that is not subject to withholding, you probably cannot wait until April to settle up. The IRS generally requires quarterly estimated payments if you expect to owe $1,000 or more after withholding and refundable credits, and your withholding will cover less than 90% of this year’s tax or 100% of last year’s tax, whichever is smaller. If your prior-year adjusted gross income was over $150,000 ($75,000 if married filing separately), the 100% safe harbor rises to 110%.10Internal Revenue Service. Estimated Tax for Individuals
The quarterly deadlines for 2026 income are:
- Q1 (January through March income): April 15, 2026
- Q2 (April through May income): June 15, 2026
- Q3 (June through August income): September 15, 2026
- Q4 (September through December income): January 15, 2027
When a due date falls on a weekend or legal holiday, the deadline moves to the next business day.11Internal Revenue Service. Estimated Tax
Fixing a Return After You File
If you discover a mistake after submitting, you can correct it by filing Form 1040-X. The IRS accepts amended returns electronically for the current tax year and the two prior years, and paper filing is still available.12Internal Revenue Service. About Form 1040-X, Amended U.S. Individual Income Tax Return
If the correction means a refund, there is a firm deadline. You must file the claim within three years of filing the original return or within two years of paying the tax, whichever is later.13Office of the Law Revision Counsel. 26 USC 6511 – Limitations on Credit or Refund Miss that window and the overpayment stays with the Treasury, however clear the claim. If the correction means you owe more, pay as soon as possible to stop interest and penalties from building.