Kateryna Dzhevaga·IRS CAA · Authorized IRS e-file Provider·Federal practice (all 50 states)·EN · RU · UK

US ExpatsJune 5, 20266 min read

Filing 1040 from Abroad: the June 15, October 15, and December 15 deadlines US expats need to know

US citizens and Green Card holders living abroad get extra time to file — but most generalist accountants miss the rules. The automatic June 15 extension, the standard Form 4868 to October 15, the discretionary December 15 for taxpayers abroad, plus combat-zone suspensions. Plus the trap that catches everyone: filing extensions never extend the payment deadline.

TL;DR

April 15 — standard 1040 deadline. US persons abroad still owe payment by this date.

June 15 — automatic 2-month filing extension for US citizens/GC holders whose tax home is abroad. No form required. Attach a statement to your return explaining qualification.

October 15 — extension by filing Form 4868 (must file 4868 by April 15, not June 15).

December 15 — discretionary additional 2-month extension. Request by letter to IRS by October 15. No response = approved.

Combat Zone — deadlines suspended for the entire combat zone deployment + 180 days after.

Gotcha: All three extensions extend the filing deadline, not the payment deadline. Interest accrues on unpaid balance from April 15.

April 15 — the baseline

For US citizens and Green Card holders living abroad, the federal income tax return is still due April 15 (or the next business day if April 15 falls on a weekend or holiday). The IRS treats expats like any other US person for the original deadline.

What matters is the distinction between filing and payment:

Filing: submitting Form 1040 with all schedules.

Payment: actually transmitting the tax owed to the IRS.

All the "expat extensions" below extend filing. None of them extend payment. Interest accrues from April 15 on any unpaid balance regardless of which extension you use.

June 15 — Automatic 2-month extension

Eligibility: On April 15, you meet one of these:

You are a US citizen or resident alien living outside the United States AND Puerto Rico, AND your main place of business or post of duty is outside the US/Puerto Rico.

You are in military or naval service on duty outside the US/Puerto Rico.

How to claim: No form. Just file your return by June 15 and attach a statement explaining which condition applies (typically: "Pursuant to Treas. Reg. § 1.6081-5, taxpayer's tax home is in [country] on April 15, 2026, qualifying for the automatic 2-month extension.").

Catch: Interest still accrues on unpaid balance from April 15. Failure-to-File penalty does not accrue during this 2-month window (you're considered timely), but Failure-to-Pay penalty (0.5%/month) and interest do.

Common mistake: filing in June without paying by April 15 and then being surprised by the Failure-to-Pay penalty + interest.

October 15 — Form 4868 extension

Eligibility: Anyone.

How to claim: File Form 4868 (Application for Automatic Extension of Time to File) by April 15 (not June 15!). E-file or paper. Free.

This gives you 6 months from the original April 15 deadline → October 15.

Strategy for expats: If you'd qualify for June 15 automatic extension AND also want until October 15, file Form 4868 by April 15. You get to October 15 either way. The expats-only June 15 is automatic; the Form 4868 to October 15 is universal.

Catch: Same as before — extension to file, not to pay. Interest + Failure-to-Pay continue.

December 15 — Discretionary additional extension

Eligibility: US person whose tax home is abroad (similar to June 15 rule). After you've already taken the October 15 extension, you can request 2 additional months to December 15.

How to claim: Send a letter to your IRS Service Center by October 15 explaining why you need more time. Common reasons:

Foreign financial institution hasn't sent statements yet (banks in some countries close fiscal year later)

Foreign tax authority hasn't issued certificate of taxes paid yet (needed for FTC calculation)

You're waiting on Schedule K-1 from a foreign partnership

Foreign employer hasn't provided foreign W-2 equivalent

The IRS does not respond if it approves. If denied, they send a denial letter. Plan accordingly — assume approved unless told otherwise.

Catch: Discretionary. Generic "I need more time" doesn't fly. Be specific about which document you're waiting on and why it requires more than the 6 months you already had.

Combat Zone

For US military, Red Cross personnel, accredited correspondents, or contracted civilians serving in a designated combat zone, IRC §7508 suspends tax deadlines.

Suspension period: from the day you entered the combat zone until 180 days after you leave it. The April 15 deadline, plus any unused portion of it from before entering, is added to the 180 days.

Example: US Marine enters Iraq on March 1, 2026. April 15 deadline → 46 days remained as of March 1. After leaving Iraq on August 1, the deadline restarts: 46 days + 180 days = 226-day extension starting August 1.

Applies to filing, payment, IRS assessment, and refund claims. Spouses (joint or separate returns) get the same suspension.

Forms: Write "Combat Zone" in red ink at the top of Form 1040 and provide entry/exit dates. Or e-file with combat zone indicator.

What about FBAR?

FBAR (FinCEN 114) is a separate filing to FinCEN, not the IRS. Different deadlines:

April 15 original due date

October 15 automatic extension (no form required — FinCEN grants it automatically every year)

FBAR does not get June 15 or December 15 like 1040. Expats use the October 15 automatic.

Practical playbook for US expat tax season

By March 15 (one month before April 15):

Estimate your tax owed for the prior year. If you'll owe, transfer the estimated balance to your IRS account via Direct Pay so it counts as paid by April 15. This avoids Failure-to-Pay penalty and interest accrual regardless of which filing extension you use.

If you need until October 15, file Form 4868 by April 15. Sets the extension.

Between April 15 and October 15:

Gather all foreign income statements, foreign tax certificates, FBAR account data, Form 8938 details.

Prepare the return. Decide FEIE vs FTC strategy.

By September 1 (45 days before October 15):

Review draft return. Identify any missing documents.

If you can't get them by October 15, draft the December 15 extension request letter to send by October 15.

By October 15:

File 1040 + Form 2555/1116/8938 etc. via e-file or paper.

Submit FBAR via BSA E-Filing System.

(If applicable) Mail December 15 extension request letter.

By December 15 (if December extension was needed):

File the return.

Pay any final balance + accumulated interest from April 15.

Common mistakes

Confusing filing extension with payment extension. Every expat eventually learns this the hard way. Pay an estimated amount by April 15.

Missing Form 4868 by April 15. The June 15 expat auto-extension only goes to June 15. To go to October 15, file Form 4868 by April 15 — not by June 15.

Forgetting to attach the statement to a June 15 return. Without the statement explaining your qualification, the IRS treats your June 15 return as late and assesses Failure-to-File penalty.

Filing the December 15 letter request after October 15. Late requests are denied. Letter must be in IRS hands by October 15.

Forgetting FBAR. FBAR is FinCEN, not IRS. It has its own October 15 auto-extension. Skipping it can cost $16,536 per account per year in non-willful penalties.

Sources

IRS — When to File (US citizens abroad)

Publication 54 — US Citizens and Resident Aliens Abroad

Form 4868 — Automatic Extension

Treas. Reg. § 1.6081-5 — automatic 2-month extension

IRC §7508 — Combat zone tax provisions

FinCEN BSA E-Filing for FBAR

*This article is general guidance for US citizens and GC holders abroad. For your specific deadlines and strategy, schedule via Telegram or email info@fintaxes.us.*

Kateryna Dzhevaga

Tax Expert

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