I filed before June 15. Why do I owe interest?

Even though the deadline to file is automatically extended to June 15 for expats, any tax owed must still be paid by April 15.

If you owe tax to the IRS and haven’t paid by April 15, you’ll have to pay accrued interest on the tax due.

This rule often proves problematic for expats. The only solution is to have your taxes prepared (or at least estimated) before April 15, so that you’ll know for sure if (and how much) you’ll need to pay.