Restore Main Street's Credit Act of 2012 - Amends the Federal Credit Union Act to exclude from the definition of "member business loan" (and related loan limits) an extension of credit made to a Main Street business (an organization, other than a nonprofit organization, with 20 or fewer full-time employees that possesses, occupies, or leases property other than a home for its business's operations).
Instructs the National Credit Union Administration Board (NCUAB) to issue guidelines for extensions of credit made by an insured credit union to a Main Street business in order to promote: (1) appropriate levels of such extensions within the credit union's total lending portfolio, and (2) the credit union's cooperative nature and its safety and soundness.