It's not a BSA issue, but an NRA signs a W-8 regardless of whether he does or does not have a TIN.
Well, that is not technically correct. An NRA that meets the substantial presence test would sign a W-9.
An alien individual meeting either the "green card test" or the "substantial presence test" for the calendar year is a resident alien.
Do not use Form W-8BEN if:
• You are a U.S. citizen (even if you reside outside the United States) or other U.S. person (including a resident alien individual). Instead, use Form W-9, Request for Taxpayer Identification Number and Certification.
You cannot mix immigration status and IRS status, it is not the same.