Wells Fargo Continues to accept the matricula consular card issued by Mexico as ID for a loan. At least they did the last time I checked. I had heard that Bank of America was as well.
If they don't have the "Right" social security card, we call that "Fraud". Commiting fraud with a social security card is a Federal Offense.
This inlcudes a fraudulent (IE: counterfeit) card or a card that actually belongs to someone else - even if you are using that card with the permission of the cards valid holder.
This is not a good time to be a person who facilitates or in any way supports the efforts of illegal aliens to obtain financing using falsified identification.
You may be aware of the burbank police now having a policy of verifying residency status with those currently in custody or arrested.
This trend is gaining momentum.
If a licensed real estate agent were found to be facilitating the efforts of an illegal alien while committing fraud, I would suspect that you would be likely to face charges of your own.
Just having a TIN (Taxpayer Identifcation Number), to my knowledge, is not going to help with identifcation for obtaining a loan. Although I would guess one is required in addition to identification.
For those who care more about this subject, here is a good link with information on the Matricula Consular card.
http://www.house.gov/garymiller/MatriculaConsularCardsMythandFacts.html R