Established in 1934, TTCU Federal Credit Union is the second-largest credit union in Oklahoma and helps people achieve their goals in life. 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 www.ttcu.com for more information. Federally insured by NCUA. Equal Housing Lender.