Any person who is not an American citizen and does not have a social security number in the U.S. must get an individual tax identification number if he/she:

• Is required to file an income tax return; 
• Is claimed as a dependent;
• Is the spouse of an American taxpayer (and a joint return is filed);
• Files a return in order to get a tax refund;
• Would like to use certain provisions allowing a reduction of U.S. source deductions.

A certified true copy of the Canadian passport must be included with any application for an individual identification number. The certification must be by a Service Canada agent or an agent approved by the U.S. government. Plan on sufficient time and the necessary travel to finalize the process.