This comprehensive guide provides a detailed overview of the transaction codes, payment frequencies, system-generated teller IDs, and operational processes within the FLEX core processing system. Designed for credit union staff and financial professionals, the guide serves as a quick-reference tool to streamline daily operations, ensure compliance, and support accurate transaction handling. Whether you’re processing teller transactions, managing certificates, or interpreting ACH postings, this course is an essential resource for mastering the FLEX environment.