A foreign country withheld more than the treaty rate — can I credit the full amount?

A tax is not creditable just because it was withheld abroad. Under sections 901 and 903 the amount must be a compulsory payment of an income (or in-lieu-of) tax. If the foreign country withheld more than you legally owed and a refund remedy exists, the excess is generally not creditable — whether or not you actually pursue the refund. The same principle applies when a reduced treaty rate was available but not obtained.

If the correct treaty rate was 10% and you could have claimed it, the portion above what was legally owed is typically treated as a non-compulsory, and therefore non-creditable, amount. The creditable piece is generally the tax you were actually liable for under foreign law and the treaty, not the over-withheld total. The practical fix is to claim the treaty rate at source or seek the foreign refund, rather than treating the excess as a US credit.

On Form 1116, focus on substantiating the foreign tax you were legally liable to pay. Keep the withholding statements, the treaty article you rely on, and any refund correspondence. If you do recover a foreign refund later, a section 905(c) redetermination may require you to amend and adjust the credit you previously claimed.