Missing TIN – We consider a TIN to be missing if it is not provided, has more or less than nine numbers, or it has an alpha character as one of the nine positions.
Example: Missing SSN: 123-45-678
Example: Missing SSN: 123-45-67899
Example: Missing EIN: 12- 345678P
Incorrect (or invalid) TIN – We consider a TIN incorrect or invalid if it is in the proper format but the Name/TIN combination does not match or cannot be found on IRS or SSA files.
Examples of Proper Format:
Correct SSN:123-45-6789
Correct EIN: 12-3456789
For additional information see Publication 1281, Backup Withholding.