US Tax Return Deadline: April 15, June 15 and Extensions

The US tax return deadline isn't a single date. It's a small calendar that depends on whether the IRS treats you as a resident, whether you had US wages with tax withheld, and where you live on the due date. Then there's the Form 4868 extension, which many people mistake for extra time to pay. It isn't. This page lays out every date, shows what a missed deadline costs, and explains how the US deadline fits with your tax return in your home country.

Anyone who has to file a US tax return usually knows one date: April 15. That's correct, but incomplete. The law ties the deadline to your IRS status, the type of income you have and where you live on the due date. Whether you're a resident at all and which form applies to you is covered on the page 1040 or 1040-NR; for the big picture of the whole return, see the guide Filing a US tax return as a European. This page is about the calendar: when you have to file, when you have to pay, what the extension really does and what each month of delay costs.

1The basic rule: April 15, for the form and the money

Under § 6072(a) of the Internal Revenue Code, the income tax return for a calendar year is due by April 15 of the following year. For tax year 2026, that's Thursday, April 15, 2027. If April 15 falls on a Saturday, a Sunday or a legal holiday in the District of Columbia, § 7503 moves the deadline to the next business day. According to the IRS, a return counts as filed on time if the envelope is properly addressed, postmarked on the due date and mailed that day.

The second half of the rule is the one many people miss: the tax is due on the same day. In the US, filing and paying are two separate obligations with the same date. Postponing the form in April does not postpone the payment. Everything else builds on this.

For fiscal years that don't match the calendar year, the deadline is the 15th day of the fourth month after year end. That's rare for individuals; almost everyone files on a calendar-year basis.

2Who can file later: June 15 and its two reasons

June 15 exists for two quite different reasons, and they work differently.

2.1Nonresidents without US wages

If the IRS treats you as a nonresident alien and you had no wages during the year with US income tax withheld, your Form 1040-NR isn't due under § 6072(c) until the 15th day of the sixth month, so June 15. This typically applies to the owner of a vacation rental in Florida, a limited partner in a US partnership or a freelancer with US income. This is a genuine due date: payment isn't due until June either. If you did have US wages with tax withheld, your 1040-NR is due April 15.

2.2Residents living outside the USA

If you're a US citizen or resident, for example as a green card holder, but live outside the USA and have your main place of work there, § 1.6081-5(a)(5) of the Regulations automatically gives you two extra months to file and pay. This applies even if you happen to be in the US on April 15. The difference from the first case: the IRS charges interest from April 15, because the actual due date is still in April. If you use this automatic extension, attach a statement to your return showing that you qualify. What else applies to Americans living in Europe is covered on the page Deadlines for Americans abroad.

The table sums up every situation for tax year 2026, including the year you move to or leave the US. For such a dual-status year, your status on December 31 determines which form you file and which deadline applies; the details are on the page Year of arrival and year of departure.

3Form 4868: what the extension does and doesn't do

In the US, an extension is a form, not a request. File Form 4868 by the original due date and § 1.6081-4 of the Regulations automatically gives you six more months to file. The IRS doesn't ask for a reason; it only gets in touch if it rejects the request. There are three ways to do it:

• Payment with a note. You pay all or part of your estimated tax electronically and mark it as an extension payment. You then don't need a separate form; the IRS treats the payment as your request.
• Electronically. Form 4868 through tax software or an advisor who e-files. You get an electronic confirmation.
• On paper. Form 4868 by mail, with a payment if you like.

You need to get three things right. First, you must make a proper estimate of your tax for the year and enter it on line 4; an extension with an obviously wrong estimate won't hold. Second, you must file on time, meaning by the April deadline or, for a 1040-NR without US wages, by June 15. Third, you need to know that the extension doesn't postpone payment.

Here's how far the extension takes you:

• Due in April: file by October 15.
• 1040-NR without US wages, due in June: file by December 15. To do so, check line 9 of Form 4868.
• Resident living outside the USA: the automatic two months and the six months run at the same time, so the end date is October 15. You check line 8 and file by June 15. After that, a letter to the IRS stating your reasons, sent by October 15, can get you two more months until December 15. This extension is at the IRS's discretion.

Under § 6081(a), more than six months is only available to taxpayers abroad. The IRS can also end an extension at any time with at least ten days' notice.

3.1The 90 percent rule

The late payment penalty doesn't apply for the extension period if two conditions are met: by the original due date, at least 90% of the year's tax has been paid, through withholding, estimated payments or the payment with Form 4868, and the rest comes with the return. Interest still runs. So if you know in April that you'll owe, pay the estimated amount along with the extension.

4What a missed deadline costs

The IRS charges two penalties plus interest. Under § 6651(a)(1), the failure-to-file penalty is 5% of the tax still unpaid on the due date for each month or part of a month, up to 25%. The deadline here includes any extension: if you extended and file by October 15, you're not late. If the return is more than 60 days late, the IRS imposes a minimum penalty. For returns due after December 31, 2025, it is $525 or 100% of the unpaid tax, whichever is less; the IRS adjusts the dollar amount for inflation.

The failure-to-pay penalty is 0.5% of the unpaid tax for each month or part of a month, also capped at 25%. If both apply in the same month, the filing penalty is reduced by the payment penalty, so the 5% becomes 4.5% plus 0.5%. After five months the filing penalty is maxed out, while the payment penalty keeps running. The IRS resets the interest rate every quarter: the federal short-term rate plus three percentage points, which for the fourth quarter of 2026 is 7% a year.

An example: without an extension, you file your 1040 for 2025 on August 10, 2026 and pay $2,000 that day, which was due April 15, 2026. From April 16 to August 10, four months or parts of months have passed. On paper, the filing penalty is four times 4.5%, so 18% or $360; the payment penalty is four times 0.5%, so 2% or $40. Because the return is more than 60 days late, the IRS checks the minimum penalty: $525 or the unpaid tax of $2,000, whichever is less. The $360 falls below that, so the IRS charges $525 for late filing, plus the $40 and interest. A simple extension in April would have avoided the filing penalty entirely.

4.1When the penalty doesn't apply

Both penalties are waived if you can show reasonable cause. For returns from tax year 2025 onward, the IRS also applies a goodwill rule automatically, the Automatic Exemption from Penalty: if you filed and paid the same return on time in each of the three prior years, no penalty is assessed for filing or paying late. Interest still applies. And if you are due a refund, you pay no penalty, because it is calculated on the tax still owed. You do have to claim the refund within three years of the due date, though, or it is lost.

4.2The deadline behind the deadline for nonresidents

Nonresidents face a second limit, and it is often the more expensive one. Under § 874(a), you are only entitled to deductions and credits if you file a true and accurate return on time. On time here means within 16 months of the due date. If you also failed to file for the prior year, this window closes sooner, as soon as the IRS writes to tell you the return is missing. For a rented US property taxed on a net basis, that can mean the rent is taxed with no deduction for interest, depreciation or expenses. How to catch up on such years is explained on the page Filing late US tax returns.

5Deadlines that run alongside the return

Besides the income tax return, there are filings with their own dates. They are easy to forget because they do not trigger any tax.

• FBAR. The report of foreign financial accounts to the Treasury (FinCEN Form 114) is due April 15, with an automatic extension to October 15, no request needed. It is filed electronically through the BSA E-Filing System, not with your tax return. A US person must file if the combined value of their accounts outside the US exceeded $10,000 at any point during the year.
• Form 8843 and Form 8840. If you exclude days from the Substantial Presence Test or claim a closer connection to your home country, you attach these forms to your 1040-NR. If you do not have to file a return, you send them to the IRS center in Austin by the due date of the 1040-NR, including extensions. If you miss the deadline for Form 8840, you cannot claim the closer connection.
• Statements at the start and end of residency. If you want to exclude up to ten days when you arrive, or use a residency end date earlier than December 31 when you leave, you file a statement with your tax return or, if you have no filing requirement, by the due date of the 1040-NR.
• First-Year Choice. If you want to be treated as a resident voluntarily in the year you arrive, you can only file the 1040 once you meet the Substantial Presence Test the following year. Until then, the only option is an extension, and with it you pay the tax as if you had been a nonresident for the whole year.
• Estimated payments. Estimated tax for the current year has its own dates; for nonresidents without US wages, the first is due June 15. More on the page Estimated tax payments with Form 1040-ES.

One detail worth knowing: according to the IRS, a dual-status return for tax year 2025 cannot be filed electronically. It goes by mail, and mail from Europe takes time. Plan your deadline accordingly.

6The deadline at home and why the order matters

7Special cases: disasters, holidays, mail from Europe

When the President declares a disaster, the IRS can postpone deadlines for those affected, by up to a year according to the IRS, depending on the date it sets (§ 7508A). This also applies to the extension request; for FBAR filings, FinCEN publishes its own notices. If you live in an affected area or keep your records there, check the IRS notice for your area.

The holiday that can push back the due date is a holiday in the District of Columbia, not in your state or back home. A public holiday in your home country does not move a US deadline. And the postmark rule applies to US mail; if you are sending from Europe, do not count on the last day, and file electronically wherever you can.

8Plan your deadlines in five steps

1. Clarify your status. Resident, nonresident or dual-status? That determines the form and the due date.
2. Pin down the due date. April 15, June 15, or the automatic two extra months if you are a resident living outside the US.
3. Estimate and pay by the due date. At least 90% of the year's tax, even if you extend.
4. Extend if documents are missing. Form 4868 or a payment marked as an extension, by the original due date.
5. Keep the side filings in mind. FBAR, Form 8843, Form 8840, residency statements, and then your return at home.

Follow these five steps and the most you pay is interest for the time money was outstanding, never a penalty for a form that came in late.

In short

• The federal return is due April 15 of the following year, or June 15 for nonresidents without US wages subject to withholding; if the date falls on a weekend or holiday, the next business day applies.
• Form 4868 extends the time to file by six months, no reason needed, but never the time to pay: interest runs from the original due date.
• File late and you pay 5% of the unpaid tax per month or part of a month, capped at 25%; after 60 days a minimum penalty applies. Pay late and you pay 0.5% per month.
• FBAR, Form 8843, Form 8840 and the statements on the start or end of residency have their own deadlines.

How we help you

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• US Tax ConsultationYour US tax question, answered by people who know both sides.
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