Quick overview

U.S. citizens and green card holders must file federal tax returns reporting worldwide income even when they live abroad (see IRS guidance on filing requirements) (https://www.irs.gov/international/individuals/filing-requirements-for-us-citizens-and-resident-aliens-abroad). Many expats qualify for exclusions or credits that reduce U.S. tax, but they still need to file and meet disclosure rules.

Who must file

Key forms and when to use them

  • Form 1040 — U.S. individual income tax return: required when gross income meets filing thresholds. (filed annually)
  • Form 2555 — Foreign Earned Income Exclusion: use to exclude qualified foreign earned income and housing amount if you meet the bona fide residence or physical presence test (see Form 2555 details) (https://www.irs.gov/forms-pubs/about-form-2555). Also see our in-depth guide on the Foreign Earned Income Exclusion for examples.
  • Form 1116 — Foreign Tax Credit: claim a credit for foreign income taxes paid to avoid double taxation.
  • FinCEN Form 114 (FBAR) — Report foreign bank accounts if aggregate foreign account balances exceed $10,000 at any time in the year. FBAR is filed electronically with FinCEN; see IRS overview for reporting guidance (https://www.irs.gov/businesses/small-businesses-self-employed/report-of-foreign-bank-and-financial-accounts-fbar). For help with disclosures, see Handling Offshore Income Disclosures and FBAR Requirements.
  • Form 8938 — Statement of Specified Foreign Financial Assets: separate FATCA reporting on Form 1040 for taxpayers above certain asset thresholds (https://www.irs.gov/forms-pubs/about-form-8938).

Internal resources:

Deadlines and extensions (current as of 2025)

  • Standard filing deadline: April 15 (tax payments due by this date to avoid interest and late-payment penalties).
  • Automatic expat filing extension: you receive an automatic two-month extension to file (to June 15) but not to pay taxes owed — interest starts accruing from April 15. (IRS: Filing Requirements for U.S. Citizens and Resident Aliens Abroad)
  • Additional extension: to get more time to file (until October 15), file Form 4868 by the April deadline or take advantage of the automatic extension procedures; taxes owed remain due by April 15.
  • FBAR (FinCEN 114) deadline: April 15 with an automatic extension to October 15 for electronic filing (FinCEN guidance).

Common pitfalls to avoid

  • Assuming you’re exempt from U.S. taxes because you live abroad. U.S. taxation is based on citizenship/residency, not residence.
  • Missing the difference between exclusions and credits: Form 2555 excludes earned income; Form 1116 credits taxes paid. Choosing the better option requires calculation.
  • Forgetting foreign-account and asset reporting (FBAR, Form 8938). These carry separate penalties and can be severe.
  • Overlooking state tax obligations. Some states maintain filing requirements for residents who move abroad—check your last state of residence.
  • Paying late instead of filing late. You can file for more time to submit forms, but interest accrues on unpaid tax after April 15.

Practical checklist (step-by-step)

  1. Determine filing requirement and collect foreign and U.S. income records (pay stubs, employer statements, foreign tax receipts).
  2. Decide whether to use Form 2555 or Form 1116 (or both in different years) after running a preliminary calculation.
  3. Prepare FBAR (FinCEN 114) and Form 8938 if asset thresholds are met.
  4. Estimate tax due and pay by April 15 to avoid interest; file by June 15 if you’re abroad (or file Form 4868 for October 15 extension).
  5. Consider professional help—expat tax rules interact with foreign social taxes, tax treaties, and state rules.

Example

A U.S. citizen living in Germany who earns $100,000 and pays German income tax can often exclude earned income with Form 2555 (if they meet the physical presence or bona fide residence test) or claim a foreign tax credit with Form 1116. The best choice depends on their specific numbers, housing amounts, and whether they have other foreign-source income or assets.

Professional tips

  • Keep detailed records of foreign pay, taxes paid, days in/out of the U.S., and foreign bank statements.
  • Reconcile employer-provided tax statements from the host country with U.S. reporting needs.
  • If you’ve missed prior-year filings, consider the IRS streamlined filing compliance or voluntary disclosure programs—get professional advice early.

Professional disclaimer: This article is educational only and not tax advice. For advice tailored to your situation, consult a licensed tax professional experienced in international tax matters.

Last reviewed: 2025 — content reflects IRS rules and common practice as of 2025.