The problem is that IRS is likely going to pay interest on the refund, and they need to know whose name and tax ID to put on the 1099-INT.  It may be only $10 in your case, but they need procedures to cover cases where it can be $1,000 or more.  Are you trying to e-file? Because there are enough questions here about problems e-filing with a 1310, that you have to learn those tricks even with an SSN for the payee.  If you paper file, just write in "Foreign" or "Canadian" where the SSN is required, and see what happens.  Is the sister the only beneficiary?  Do you have a US beneficiary to whom the refund could be paid directly?