There is no Internal Revenue Service (IRS) representative in Korea. The consular staff in Seoul is not qualified or authorized to assist you with your tax questions or to help you determine which IRS forms you may need to file. Questions about U.S. state taxes and/or Korean taxes should be directed to the appropriate state or agency. The U.S. Embassy in Seoul cannot advise you about or provide forms for U.S. state or Korean taxes.
If you are a U.S. citizen or resident alien, the rules for filing income, estate, and gift tax returns and paying estimated tax are generally the same whether you are in the United States or abroad. Your worldwide income is subject to U.S. income tax, regardless of where you reside.
You may also wish to refer directly to the IRS website or contact them directly for the information you require.
* Note : IRS Announces Changes to Individual Taxpayer Identification Numbers
The IRS recently announced major changes to the individual taxpayer identification number (ITIN) system. Any ITIN not used on a federal tax return at least once in the last three years will no longer be valid as of January 1, 2017 for use on a tax return unless the taxpayer renews the ITIN. In addition, all ITINs issued prior to 2013 will begin to expire this year and taxpayers will need to renew them.
The first pre-2013 ITINs that will expire are those with middle digits of 78 and 79 (Example: 9XX-78-XXXX). The renewal period for these ITINs began October 1, 2016. The IRS began to mail letters to this group of taxpayers in August to inform them of the need to renew their ITINs in order to file a tax return, and explain the renewal steps. The IRS will announce the schedule for expiration and renewal of ITINs that do not have middle digits of 78 and 79 at a future date.
If taxpayers have an expired ITIN, not renewed before filing a tax return next year, they might face a refund delay and be ineligible for certain tax credits, such as the Child Tax Credit and the American Opportunity Tax Credit, until they renew the ITIN.
For more information about ITIN expiration and who requires an ITIN, see the ITIN page at IRS.gov.