If you're a Yank, that Thai interest needs to go on your US tax return. But, you can get a one-for-one tax credit for those Thai taxes paid, as Thailand has primary taxation rights on interest earned in Thailand. Of course, you can't get this credit if you waste time submitting a Thai tax return -- and Thailand refunds these taxes. A couple of related scenarios. IRS Pub 514 says: If you can get a tax refund from Thailand, then you can't claim a credit for same on your US tax return. But, you can't get a refund if you don't have a Thai tax TIN. And from many reports on this forum, and others, folks have been told they can't get a TIN without a work permit, or don't owe any taxes, whatever. Thus, I've never tried to get a TIN. Yes, maybe a lame excuse if audited. But certainly not blatant tax evasion -- in the unlikely (<1%) chance of having a three figure tax credit triggering some audit algorithm. Anyway, if you don't have a TIN, are a Yank, and have some Thai tax withholding -- this credit route vice filing a Thai tax return is the way to go. Of course, if you're a Yank pauper, and don't have any taxable income (standard deduction greater than AGI), thus can't utilize a credit -- then, yeah, spend some time filing a Thai tax return to get your measly withholding tax back; certainly you're in a situation to need it.