Missing a deadline can cost more than late fees – it can trigger penalties, interest, and even the loss of tax benefits. Advance preparation is essential if you live abroad or run a business with US ties.
Below are the key dates you need to know for filing your 2025 tax year returns in 2026, grouped by taxpayer type for easier navigation. If you are looking for help with this, check out these tips to find the best expat tax accountant for your situation.
To get expert help with your US tax filings in 2026, schedule a consultation with us.
Rather than listing all the different deadlines by month, we grouped them by target group.
Tax Deadlines For Individuals In 2026
- April 15, 2026 – The due date for individual returns for the 2024 tax year. Interest and penalties will start accruing for any tax you owe after this date, even if you file an extension. You should make an estimated payment by April 15 to avoid interest and penalties if you owe taxes.
- June 15, 2026 (automatic expat extension) – Individual tax return due if residing outside the US. (For more info, check out our US Expat Tax Guide.) This is an automatic 2-months extension to file and pay. However, interest starts accruing on April 15. If you expect to owe tax, you should make an estimated payment by April 15.
- October 15, 2026 – The final deadline to file for individuals who requested an extension. No further extensions are automatic after this date, and late-filing penalties begin immediately.
If you paid independent contractors over a certain threshold, you must provide them with a Form 1099. As a freelancer, you should receive a Form 1099-NEC (non-employee compensation) from your clients.
- January 31, 2026 – Deadline to send Form 1099-NEC to contractors
Tax Due Dates For Sole Proprietor And Single-Member LLC In 2026
Sole proprietors and single-member LLCs pass income through to the person running it and therefore have the same due dates as for individuals. See above for the due dates.
The business income is reported on Schedule C as part of the individual tax return. If you’re a US expat with a single-member LLC, don’t assume simplified filing.
International activity may trigger extra forms such as 5471 or 8865, depending on ownership or foreign transactions.
Form 5472 is due on April 15, 2026, together with your company’s Form 1120. If you file an extension for your corporate tax return, Form 5472 is due together with the tax return on October 15, 2026.
Deadlines For Multi-Member LLC In 2026
Multi-member LLCs are taxed as partnerships. See below for partnership tax due dates.
Tax Due Dates For Partnership & S Corporation in 2026
Partnership on a calendar year and S Corporation:
- March 17, 2026 – Initial due date for Form 1065 with Schedule K-1 for partnerships and Form 1120S with Schedule K-1 for S corporations.
- September 15, 2026 – The final deadline for partnerships and S corporations that filed for an extension.
Partnerships with a different tax year must file tax returns by the 15th day of the third month after the tax year-end date.
S Corporation Election Deadline
- March 17, 2026 – Last day to file Form 2553 to elect to be treated as an S Corporation for the 2025 calendar year. (Learn here if an LLC or S Corp is more beneficial). Alternately, you can also elect to have your LLC treated as an S Corporation within 75 days of incorporating your business.
Tax Due Dates For C Corporations
Deadlines for filing corporate tax returns (Form 1120):
- April 15, 2026 – Initial deadline to file corporate tax returns.
- October 15, 2026 – Final deadline if you requested a 6-month extension with Form 7004.
If your C Corporation has foreign shareholders or operations, you may also need to file forms such as 5471 or 8825. Even timely Form 1120 filings won’t protect you from penalties for missing those.
Due Dates For Quarterly Estimated Payments
When tax payments are not automatically withheld each month, e.g., for the self-employed, you need to make quarterly estimated tax payments.
- January 15, 2026 – Last estimated tax installment for the 2025 tax year.
- April 15, 2026 – 1st installment of 2026 estimated tax.
- June 16, 2026 – 2nd installment of 2026estimated taxes.
- September 15, 2026 – 3rd installment of 2026 estimated taxes.
- January 15, 2027 – 4th installment of 2026 estimated taxes.
If you expect to owe more than $1,000, paying quarterly keeps you out of underpayment penalties. This matters especially for digital nomads or contractors abroad who have little or no US withholding.
US persons with foreign bank accounts must report them if they meet certain requirements.
- April 15, 2026 – The FBAR deadline corresponds to the tax deadline. However, it has an automatic extension until October 15. You file your FBAR separately from the tax return but it has the same due date as individual tax returns.
- October 15, 2026 – Extended due date, FinCEN grants an automatic extension to October 15, 2025.
Even though there’s an automatic extension, late filings can still lead to large fines. File through the BSA E-Filing system, not with your tax return, to stay compliant.
State Tax Deadlines
Depending on your former home state, you may have to file a state tax return. Please check any state you have to file in. Not all state tax calendars align with the federal 2026 tax deadlines.
States like California, New York, and Virginia can still tax income from former residents or state-source income even if you live overseas. Check each state individually before assuming you’re exempt.
How to Get Ready: Essential Filing Checklist for Expats in 2026
Good preparation saves time, prevents errors, and protects you from missed deductions or penalties. Use this streamlined checklist before filing your 2025 tax return in 2026.
Key Documents to Gather
Personal details
• Social Security numbers, foreign address, prior-year return
Income records
• Foreign and US pay slips, Forms W-2 or 1099
• Self-employment income or invoices
• Investment or rental income statements
Expat deductions and credits
• Proof of foreign residence or housing costs
• Travel log for Physical Presence Test
• Foreign tax payment records for the Foreign Tax Credit
Foreign accounts and assets
• Year-end bank or investment statements showing highest balance
• Pension or life insurance statements with cash value
• Crypto or digital assets held abroad (if reportable)
Business owners
• EIN and incorporation documents
• Annual financial statements and partner/shareholder info
• Forms for cross-border entities (5471, 5472, 8865)
Payments and estimates
• Quarterly estimated tax receipts
• Proof of any US tax withheld
State considerations
• Prior state returns or documents proving non-residency
Smart Filing Tips to Stay Organized and Avoid Last-Minute Stress
- Start early. Most expat tax professionals fill their calendars well before June.
- Check both FBAR and Form 8938 thresholds. Many expats must file both.
- Keep all tax records for at least six years. Save digital copies for easy access.
- Use the IRS year-end Treasury exchange rates when converting foreign balances.
- Track estimated payments to prevent underpayment penalties.
- Verify mailing and contact info with the IRS to avoid missed notices.
Get Ready To File Your 2025 Taxes
Begin gathering your documents now, foreign bank statements, income slips, housing records, and proof of FEIE or treaty eligibility. Waiting until March or April can mean rush fees, missing documents, or delayed refunds.
Many expat tax preparers become overwhelmed close to the deadlines, so starting early helps you avoid stress and mistakes.
The more proactive you are, the easier it becomes to manage your filings year after year.
Vincenzo Villamena, CPA is Founder and CEO of Online Taxman. Having previously worked at PwC in New York, he has 20 years' experience in expat taxes and regularly appears in the media as a thought leader in accounting and finances for overseas Americans. Vincenzo loves to travel, is fluent in Spanish, Portuguese, and Italian, and currently resides in Rio De Janeiro, Brazil.
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