There is no Internal Revenue Service (IRS) office at the U.S. Embassy in Bangkok. The ACS staff is unable to answer inquiries about the preparation and filing of U.S. taxes.
Click these links from the IRS for comprehensive guidance for International Tax Payers, Taxpayers Living Abroad, Videos for Overseas Taxpayers, and the IRS’s Guide for U.S. Citizens and Resident Aliens Abroad (PDF 2.5MB)
The State Department reminds all U.S. Citizens and Legal Permanent Resident Aliens that you are responsible for filing U.S. federal income tax returns while living overseas.
If you are transporting currency or monetary instruments abroad, or back to the United States, you will need to file the appropriate report.
If you are a U.S. government employee working overseas, you cannot claim the Foreign Earned Income Exclusion. For additional information, visit the IRS website under U.S. government civilian employees stationed abroad.