For US citizens and green card holders in South Korea

US Taxes for Americans Living in South Korea

Moving to South Korea does not end your US tax filing. Here is what Americans living there file each year, how the treaty and the social security rules between the two countries work, and what to do about missed years.

US returnFBARForm 8938Treaty: yesTotalization: yes

Request a Quote What to File

Quick answer

Do US citizens living in South Korea have to file US taxes?

Yes. The US taxes citizens and green card holders on worldwide income wherever they live. Living in South Korea gives an automatic extension to June 15, accounts there above US$10,000 in total need an FBAR, and the foreign tax credit or the foreign earned income exclusion (US$132,900 for 2026) usually prevents double tax. The US has an income tax treaty with South Korea, and a social security agreement has been in force since April 1, 2001.

Prepared by Illuminous Accounting · Sources checked November 11, 2026

At a glance

Yearly US return: Yes, on worldwide income; due June 15 automatically when living abroad
US tax treaty with South Korea: Yes, per the IRS list (saving clause applies to US citizens)
Social security agreement: Yes, in force since April 1, 2001
Accounts in South Korea: FBAR above US$10,000 in total; Form 8938 above higher limits
Behind on filing: Streamlined: 3 years of returns, 6 years of FBARs

Do Americans living in South Korea have to file US taxes?

Yes. The United States taxes its citizens and green card holders on worldwide income wherever they live, so moving to South Korea does not end the yearly US return (IRS Pub 54). Salary, self-employment income, interest and pensions from South Korea all go on it, converted from Korean won to US dollars.

The return is due April 15. If you live and work outside the US on that date, you get an automatic 2-month extension to June 15, and you can extend further to October 15. Interest still runs on tax paid after April 15.

Is there a US tax treaty with South Korea?

The US has an income tax treaty with South Korea (IRS treaty list), but US treaties contain a saving clause: they generally do not reduce US tax for US citizens, with specific exceptions written into each treaty (IRS Pub 54). So the treaty helps at the edges, for example with pensions or the order of tax credits, while the main relief comes from the exclusion or the credit.

Tool	What it does	Watch for
Foreign earned income exclusion	Excludes up to US$130,000 (2025) or US$132,900 (2026) of foreign earned income	Only earned income; does not reduce self-employment tax (Pub 54)
Foreign tax credit	Credits income tax paid in South Korea against US tax on the same income	Works best where the local tax is at least as high as the US tax

We run the figures both ways before choosing. More in FEIE vs foreign tax credit.

Money kept in South Korea

The US wants to know about money you keep in South Korea. Once your non-US accounts together pass US$10,000 at any point in the year, an FBAR is due, normally April 15 with an automatic extension to October 15 (IRS).

Larger balances bring Form 8938 as well. For someone living abroad the starting point is US$200,000 at the end of the year or US$300,000 at any time (double for a joint return), and the penalty for leaving it out is US$10,000 (IRS).

Missed years while living in South Korea

Behind on US filings while living in South Korea? Eligible non-willful filers who live abroad can use the Streamlined Foreign Offshore Procedures: file the last 3 years of returns and 6 years of FBARs, pay any tax and interest, and the IRS does not charge the usual failure-to-file, information return or FBAR penalties (IRS). More in our Streamlined guide.

Your Korean return and ours

Americans in South Korea include teachers, defense-sector contractors, Korean Americans and employees of Korean companies.

We prepare the US side only. Your Korean tax return stays with a local adviser in South Korea, and we can work from the figures on that return so both sides match.

How we help

Gurleen Kaur, CPA licensed in British Columbia and Washington State, prepares and signs US returns for Americans living in South Korea: the yearly return with the exclusion or credit, FBAR and Form 8938, and Streamlined catch-up. Every engagement starts with a fixed written quote after we review the file. See the yearly filing package.

Treaty and law references: the US and South Korea

Treaty and social security

The IRS lists the 1976 income tax treaty, signed June 4, 1976. General effective date (IRS Table 3): treaty Jan. 1, 1980 (IRS treaty documents for Korea; treaty text; IRS Table 3).
Saving clause: paragraph 4 of Article 4 (General Rules of Taxation), which lets the United States tax its citizens as if the treaty had not come into effect, apart from listed exceptions.
Article 5 (Relief from Double Taxation), on relief from double taxation.
Article 23 (Private Pensions and Annuities) and Article 24 (Social Security Payments) and Article 25 (Exemption from Social Security Taxes), on pensions and social security.
Article 19 (Dependent Personal Services), on employment income.
Social security: the US agreement with South Korea entered into force on April 1, 2001 (SSA).

US law

Foreign earned income exclusion: Code section 911 (IRS Form 2555 instructions).
Foreign tax credit: Code section 901 (IRS Pub 54).
Form 8938: Code section 6038D and Treas. Reg. section 1.6038D (IRS Form 8938 instructions).
FBAR: 31 USC 5314 and 31 CFR 1010.350 (IRS Internal Revenue Manual 4.26.16).
Green card holders and residency: Code section 7701(b) (IRS Pub 519).

The tax rules of South Korea also apply to you there; a local adviser covers that side.

Common questions

Do Americans in South Korea pay US tax?

Yes. US citizens and green card holders file a US return on worldwide income wherever they live. Living in South Korea on April 15 gives an automatic extension to June 15, and tax paid in South Korea or the foreign earned income exclusion often reduces the US tax to little or nothing.

Does the US-South Korea tax treaty stop double taxation?

Partly. The treaty exists, but its saving clause lets the US tax its own citizens as if there were no treaty, with listed exceptions. The main relief is the foreign tax credit or the foreign earned income exclusion.

Do I pay social security in both the US and South Korea?

Generally not. The US-South Korea social security agreement, in force since April 1, 2001, assigns your work to one system.

What if I never filed US taxes while living in South Korea?

If it was not willful, the Streamlined Foreign Offshore Procedures let you file 3 years of returns and 6 years of FBARs, and eligible people living abroad do not pay the usual failure-to-file, information return or FBAR penalties.

Sources

Every rule and figure on this page links to the IRS, CRA or other official source it comes from. Amounts change; we re-check them before each engagement.

Gurleen Kaur, CPA licensed in British Columbia and Washington State. Last updated November 11, 2026. This page is general information, not tax or legal advice for your situation.

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