The IRS requires that casinos and other gambling establishments withhold 30% of the gambling winnings of International visitors. However, due to the U.S. Canada Tax Treaty, Canadians can offset gambling losses against the gambling winnings reported on form 1042-S. and get some or all of the gambling tax back! Non U.S. citizens that are residents of certain other countries* may also qualify for a refund of the 30% withholding on their casino winnings.