Accredited ACH Professional (AAP) Practice Exam 2025 - Free AAP Practice Questions and Study Guide

The selected answer identifies ANSI ASC X12.823 as the transaction set associated with Lockbox operations. This transaction set is specifically designed to facilitate the electronic transmission of financial and payment-related information between institutions, including details about the payments received in locked boxes. In Lockbox operations, financial institutions collect and process checks and payments for their clients, and the ANSI ASC X12.823 transaction set allows for the efficient communication of this data, enabling businesses to reconcile and manage their cash flow effectively.

The other transaction sets mentioned serve different purposes. ANSI ASC X12.835 is primarily used for health care claim payment and remittance notices, while ANSI ASC X12.820 deals with payment order and remittance advice information specifically for services. ANSI ASC X12.813 focuses on electronic funds transfer and does not relate directly to Lockbox operations. Understanding the distinctions between these transaction sets highlights why ANSI ASC X12.823 is the appropriate choice for Lockbox operations.