If you registered at a public event or through a registration drive in Shelby County, you may not be registered at all:
Several Mid-South groups that held voter registration drives asked registrants for only the last four digits of their social security numbers. But O.C. Pleasant with the Election Commission says all nine digits are required to be registered in Tennessee.
"We're going to reject those without the full social security number. They will have the opportunity based on law to correct, and have until five days before the election to do that."
Those who did not give out their full social security number during registration should keep an eye on the mailbox for a letter allowing them to correct that information.
The article does not say, but you may be allowed to fix this at the normal registration locations. This link has a list of the kinds of offices that register people.