Direct deposit transactions in the United States travel through the Automated Clearing House (ACH) network. The rules and standards that govern how these transactions are formatted, transmitted, and settled are established and maintained by NACHA (formerly the National Automated Clearing House Association). NACHA ensures that all financial institutions involved—the Originating Depository Financial Institution (ODFI, Option C) and the Receiving Depository Financial Institution (RDFI, Option B)—follow the same protocols for timing, security, and error resolution. While the Federal Reserve and other government agencies regulate banking, NACHA is a non-profit organization that manages the private-sector rule-making process for the ACH network. Payroll professionals must adhere to these rules to ensure timely pay delivery and to handle reversals or returns correctly.