What is Form 8833 and when do I need to file it to claim a treaty position?

Form 8833 is the Treaty-Based Return Position Disclosure you attach to your tax return when you're relying on a U.S. tax treaty to override the normal tax rules in a way the IRS wants disclosed. Common triggers include using a treaty residency tie-breaker to be taxed as a nonresident, or claiming a treaty reduces or eliminates U.S. tax on certain income above set thresholds. It explains which treaty and article you're invoking and why. Not every treaty benefit requires it—small reductions in withholding via a W-8BEN usually don't—but taking a position that changes your residency or substantially cuts your tax generally does. Failing to file when required can carry a penalty. If you're taking an aggressive or unusual treaty position, document the article and reasoning carefully, since this form puts the IRS on notice of exactly what you're claiming.