durberville knows that. The problem is that TransUnion (USA) is treating a Canadian SIN as if it were an USA SSN. I see that TransUnion also does business in Canada. Perhaps there is no overlap between valid SIN's and SSN's, or TransUnion has some other method of distinguishing them, and they can use them as an unambiguous record key?
Per OP's word and my interpretation, it is not the case as TU claimed it is a SSN instead of SIN, TU did not act on OP's request:
Originally Posted by
durberville
I've faxed, mailed, and called Transunion (including speaking to a supervisor) asking to replace the Canadian SIN with my US ITIN #. Every single person I've spoken to says it's not possible, and insists my Canadian SIN is an SSN
So despite the confusion over SIN vs. SSN and potentially TU's stupidity, nothing has been done.
I believe OP's ultimate goal is to replace the ITIN with SIN or in the alternative, using his SIN. My previous post said it is impossible.