TTCU Federal Credit Union is the second-largest credit union in Oklahoma, serving more than 137,000 members with 18 branch locations. Established in 1934, TTCU helps people achieve their goals in life by showing them practical financial solutions. As a not-for-profit organization, TTCU's financial success is returned to members in the form of low-rate loans and high-rate savings accounts. Call 1-800-234-8828 or visit our website for more information. Federally insured by NCUA. Equal Housing Lender.