Generally, U.S. citizens and resident aliens must pay federal tax on their worldwide income, including income received while living outside the country. Even those who qualify to exclude foreign earned income for tax purposes, or to claim a credit for taxes paid to other countries to offset their U.S. tax liability, generally must still file a federal tax return. Failing to file may disqualify a person from these opportunities to reduce or eliminate their U.S. tax bills, leading to additional tax assessments with IRS penalties added.

People living abroad typically qualify for an automatic two-month extension to file, meaning that they may file their 2023 federal tax returns anytime through June 17, 2024. However, this extension applies only to filing, not to taxes owed. The IRS will generally add interest charges to any tax amounts not paid by the standard April filing deadline.

Remember also that if you own or control financial accounts based outside the U.S., you may need to report not only the income from those accounts, but also the account balances on your tax return. You may also have to file a special Foreign Bank Accounts Report (FBAR) form. You cannot include the FBAR with your tax return, as it must be filed with a different treasury department than the IRS.