Tennessee Valley Federal Credit Union has been open since 1936. It's the 5th largest credit union in Tennessee with assets totaling $1.55 Billion and providing banking services to more than 147,000 members. Membership: The credit union is a community-based financial institution. People living, working, or worshipping in the credit union's geographic area can become a member and access banking services. Membership is also open to immediate family of current members.