Metro 2 File Format — Structure, Layout & Record Types Explained
Complete guide to the Metro 2 file format: header record, base segment, J1/J2 appendages, K segments, and trailer record. Includes field positions, lengths, and layout examples.
Core components
A Metro 2® file includes a header record, one base segment per account, optional appendage segments (J1, J2, K1–K4, L1, N1) when applicable, and a trailer record with file-level totals. Accurate sequencing and balancing are essential for acceptance by CRAs.
Appendage strategy
Only include optional segments when the scenario warrants them; avoid noise that can confuse ingest and consumers.
When renumbering accounts, include L1 to preserve lineage. For purchases/sales, use K2; for original creditor context, use K1.
Edits and acceptance
Expect CRA edits that cross-check status, balances, dates, and permitted values. Build preflight checks locally to catch common mismatches before submission.