Financial Information Reporting (X12 821) enables organizations to exchange detailed financial data, accounting records, and related reference information in a structured electronic format. Financial institutions, corporations, government agencies, and service providers send this transaction set to communicate financial statements, account balances, transaction summaries, and accounting classifications. The transaction set uses the B2A (Set Purpose) segment to establish the reporting intent, the DTM (Date/Time Reference) segment to timestamp financial periods or reporting dates, and the TRN (Trace) segment to uniquely identify the transmission for reconciliation and audit purposes. Supporting segments such as N1 (Name) and PER (Administrative Communications Contact) provide sender and recipient identification.

Consider a scenario where First National Bank sends a monthly financial report to Acme Corporation, its corporate client. The bank structures the 821 transaction with a B2A segment indicating “monthly reporting,” includes DTM segments marking the reporting period (for example, January 1–31, 2024), and populates multiple entity loops for different business divisions within Acme. Within each entity loop, the bank uses ACT segments to identify specific accounts, then populates the FIR loop with detailed financial information including current balances (via the AVA segment), rate details (RTE segment), and transaction summaries (TSU segment). The FA1 and FA2 segments provide accounting classification data, allowing Acme to automatically post the received data into its general ledger system.