Staying compliant during tax season requires understanding the exact tax deadlines that apply when you live abroad. U.S. citizens, green card holders, and non-resident aliens face multiple filing deadlines, tax payment obligations, and reporting rules for foreign financial accounts. Missing a tax filing deadline can result in penalties, interest, and long-term compliance issues.
Below are the most important tax deadlines for the 2026 tax season when filing your 2025 tax return.
March 16, 2026 – Form 3520-A Filing Deadline
March 16, 2026 is the filing deadline for Form 3520-A, which reports foreign grantor trusts.
This tax deadline applies to U.S. citizens who own or are associated with a foreign trust. Filing Form 3520-A is a legal obligation separate from your income tax return. Failure to meet this filing deadline can trigger a $10,000 penalty, even if no taxes are owed. This requirement is enforced by the Internal Revenue Service and is unrelated to whether you owe taxes for the tax year.
April 15, 2026 – Regular Federal Tax Deadline and Interest Start Date
April 15, 2026 is the regular federal income tax due date. However, qualifying U.S. citizens and resident aliens abroad receive an automatic two-month extension to file their return and pay federal income tax due with the return through June 15, 2026.
Interest on unpaid income tax generally runs from April 15, even during the automatic two-month extension. However, the failure-to-pay penalty generally does not begin until after June 15 for taxpayers who qualify for the automatic extension.
Quarterly Estimated Tax Payments for the 2025 Tax Year
If your taxable income is not subject to withholding and you expect to owe taxes of $1,000 or more, the IRS requires quarterly estimated tax payments to cover your annual tax liability. This most commonly applies to independent contractors, investors, and self employed expats earning foreign income while they live abroad.
Missing a quarterly payment can result in underpayment penalties, even if you ultimately receive a tax refund after filing your income tax return.
Quarterly estimated tax payment due dates for the 2025 tax year are:
- April 15, 2025 – First estimated tax payment
- June 16, 2025 – Second estimated tax payment
- September 15, 2025 – Third estimated tax payment
- January 15, 2026 – Fourth estimated tax payment
These estimated payments help reduce unpaid taxes, manage your tax bill throughout the tax year, and minimize penalties when you file your federal tax return during tax season.
If you are unsure how to calculate or submit estimated payments, see our complete guide on how to make estimated tax payments as a U.S. expat.
April 15, 2026 – FBAR Filing Deadline (Automatically Extended to October 15)
April 15, 2026 is the FBAR filing deadline for reporting foreign financial accounts, but all taxpayers automatically receive a free extension that moves the final FBAR filing deadline to October 15, 2026.
U.S. taxpayers with foreign bank accounts and other foreign financial accounts exceeding $10,000 in aggregate must file a foreign bank account report. No separate extension request is required, and this filing obligation applies even if no tax payment is due and no tax liability results from the account.
April 15, 2026 – C Corporation Filing Deadline (Form 1120)
April 15, 2026 is the filing deadline for calendar-year C corporations filing Form 1120.
This tax deadline applies to U.S. corporations and foreign-owned entities with U.S. operations. If April 15 were a legal holiday, the filing deadline would shift, but no adjustment applies in 2026.
June 15, 2026 – Expat Tax Filing and Payment Deadline (Automatic Two-Month Extension)
Qualifying taxpayers abroad automatically receive until June 15, 2026 to file their federal income tax return and pay federal income tax due with the return. No advance extension request is required. Interest on unpaid income tax still accrues from April 15.
October 15, 2026 – Extended Federal Tax Filing Deadline and Final FBAR Deadline
October 15, 2026 is the extended tax filing deadline for taxpayers who file Form 4868 and also the final deadline to file the FBAR.
This extended deadline provides additional time to complete your federal tax filing, gather necessary documents, and claim benefits such as the foreign earned income exclusion or the foreign tax credit. While U.S. expats may still request an additional extension to file their federal tax return beyond October 15, no further extensions are available for the FBAR, making October 15 the absolute final deadline to report foreign financial accounts.
December 15, 2026 – Additional Extension for Expats
December 15, 2026 is a discretionary extended deadline available to expats who request it in writing.
This month extension is not automatic and requires a reasonable explanation. It is typically used by taxpayers with complex filing requirements, delayed foreign financial records, or multiple foreign accounts. Interest on unpaid taxes continues to accrue until payment is made.
Learn who qualifies and how to request this discretionary extension in our guide to getting an extension to December 15 for expats.
U.S Tax Deadlines for Non-Resident Aliens
Non-resident aliens with U.S.-source income must follow specific tax deadlines and filing requirements that differ from those for U.S. citizens and green card holders, making timely tax filing essential to avoid penalties and interest.
April 15, 2026 – Non-Resident Alien Filing Deadline (Form 1040-NR)
April 15, 2026 is the tax filing deadline for non-resident aliens filing Form 1040-NR.
This deadline applies to individuals earning U.S.-source income subject to U.S. income tax. Meeting this filing deadline is essential to remain compliant and avoid penalties.
Related: 1040 vs 1040NR: Selecting the Right Tax Form
April 15, 2026 – Form 5472 With Pro Forma 1120 Deadline
April 15, 2026 is the filing deadline for Form 5472 with a Pro Forma Form 1120.
Foreign nationals who own U.S.-based LLCs must file this form to report transactions involving foreign owners, foreign bank accounts, and related parties. This filing requirement applies even if the LLC has no income or tax liability.
To understand who must file and how to stay compliant, review our in-depth explanation of IRS Form 5472 filing requirements for foreign-owned LLCs.
What Happens If You Miss a Tax Deadline?
Missing a tax deadline can result in penalties, interest, and delays in processing your tax refund.
Late tax filing and unpaid taxes may trigger failure to pay penalties and ongoing interest charges. In certain cases, disaster relief may extend tax deadlines, but relief must be confirmed based on location and eligibility.
For a detailed breakdown of penalties, interest, and next steps, read our guide on what happens if you miss the tax deadline as an expat.
Get Help Staying Compliant With Expat Taxes
Managing expat taxes involves strict filing requirements, multiple tax deadlines, and detailed reporting of foreign financial accounts. Staying compliant is a legal obligation for U.S. citizens who live abroad.
At 1040 Abroad, we provide clear tax advice, assist with tax filing, calculate estimated tax payments, and help reduce tax liability across multiple foreign countries.
