Taxpayers who filed an extension for their 2025 federal returns have until October 15, 2026 to file, and a return filed more than 60 days past its due date carries a minimum failure-to-file penalty of $525 or 100 percent of the tax owed, whichever is less. The figure comes from the IRS failure-to-file penalty page, which lists a different minimum for each due-date year, and it is higher than the $510 that applied to returns due in 2025. The extension covers filing only and does not move the date for paying tax.
With the deadline eleven days from the date of this article, the IRS’s own rules decide what a late return costs, and two separate penalties are involved.
October 15, 2026 and what the extension covers
The IRS says a taxpayer who requests an extension has until October 15 to file. For 2025 returns, that is October 15, 2026. The agency is explicit that the extension is only for filing the return. Tax owed was still due by the April filing date, and an extension does not delay that payment, according to the IRS extension page.
Interest runs on any unpaid balance from the April deadline regardless of the extension. For individuals, the IRS set the underpayment rate at 7 percent per year, compounded daily, for the fourth quarter of 2026, which covers October 1 through December 31, according to its quarterly interest rate announcement.
Why the minimum is $525 and not $510
The IRS publishes the minimum failure-to-file penalty in a table keyed to the return’s due date without extension. Returns due from January 1 to December 31, 2025 carry a $510 minimum. Returns due after December 31, 2025 carry $525. A 2025 tax return was originally due in April 2026, so it falls in the later row, and the minimum for it is $525. The earlier $510 figure belongs to returns due in 2025, which means tax year 2024 returns.
The same IRS table lists $485 for returns due in 2024, $450 for 2023 and $435 for 2020 through 2022. The amounts are adjusted for inflation, so which row applies depends on when the return was originally due, not on when it was eventually filed. The IRS page was last reviewed on February 7, 2026, and is the source for every figure in this section: the failure-to-file penalty page.
Lesser of $525 or the tax owed
The minimum is a floor with a ceiling built in. When a return is more than 60 days late, the penalty is the fixed minimum or 100 percent of the underpayment, whichever is less. A taxpayer who owes $200 at filing time faces a penalty capped at $200, not $525. A taxpayer who owes nothing, because withholding or credits covered the full tax, has no underpayment for the penalty to attach to, since the percentage is applied to the tax due after payments and credits.
For an extended return, the lateness is counted against the extended due date. Sixty days after October 15 is December 14, 2026, so the minimum comes into play for returns filed after that date.
Failure-to-file and failure-to-pay run side by side
The failure-to-file penalty is 5 percent of the tax due, less any tax paid on time and available credits, for each month or partial month the return is late. It accrues up to a maximum of 25 percent. The failure-to-pay penalty is separate: 0.5 percent of the unpaid taxes for each month or part of a month, also capped at 25 percent, as described on the IRS failure-to-pay page.
When both apply in the same month, the IRS reduces the failure-to-file charge by the failure-to-pay amount. The combined rate is 4.5 percent for filing plus 0.5 percent for paying, or 5 percent in all, rather than 5 percent plus 0.5 percent. After five months the failure-to-file penalty reaches its ceiling, while the failure-to-pay penalty keeps accruing until the balance is paid or the 25 percent cap is reached. On the IRS rates, the two charges together can approach 47.5 percent of the original balance, which is simple arithmetic on the published figures.
The payment-side rate can change. The IRS says it rises to 1 percent a month if tax stays unpaid ten days after a notice of intent to levy, and falls to 0.25 percent a month during an approved payment plan. Penalties may be waived or reduced for reasonable cause, though interest cannot be removed unless the penalty itself is eliminated.
Filing is free, and filing without paying still stops the larger penalty
Two points matter on a live deadline. Filing a federal return costs nothing through the IRS’s Free File program, which offers guided tax software at no cost for adjusted gross income of $89,000 or less and Free File Fillable Forms, available online at any income level, according to the IRS Free File page. No tax professional or paid service is needed to meet the deadline.
The second point is how the two penalties respond to filing. The failure-to-file penalty accrues for each month the return is late, so a return filed by October 15 prevents it from starting. A taxpayer who cannot pay the full balance still stops that larger monthly charge by filing, and the smaller failure-to-pay charge continues only on the amount left unpaid. Filing and paying are separate acts with separate consequences, which is why the IRS treats the extension as a filing relief only.
The deadline rests on a single IRS table and two rules: the 2025 minimum penalty row begins after December 31, 2025, the amount is $525, and the penalty is the lesser of that figure or 100 percent of the underpayment, as the IRS states on its failure-to-file penalty page.
Refund deadlines and notice records for IRS filers
The IRS Refund Recovery Kit is written for people who have filed a return and are waiting on, or chasing, a refund that is late, reduced by an offset or sent but never received. It deals with the stage after filing, when the question is what the status message or the notice in the mailbox means.
The IRS Refund Recovery Kit is a 13-page kit that includes a notice decoder, the refund-trace steps for Form 3911, a refund status tracker spreadsheet and the 3-year refund deadline.
Get the notice decoder and refund tracker in The IRS Refund Recovery Kit →
An AI model assisted with drafting; every penalty figure and date was taken from the IRS pages linked in the text.
Warren Cohen is a finance writer based in Phoenix, Arizona, covering personal finance topics including credit, banking, and beginner investing. He earned his degree in business administration from Arizona State University and began his career working in consumer finance, where he gained direct experience with lending and credit systems. He now writes for personal finance websites and fintech platforms, focusing on clear, practical content that helps readers make informed financial decisions.
