PreflightWhy payments fail
Preflight is a pre-execution and post-execution control layer for payments. This page routes common mid-intent questions into the reference library: network rejects, scheme returns, and operational stuck states — not generic advice.
Use the sections below to jump to operator-grade pages; then use the API reference to see how scenarios are modeled in the sandbox.
SWIFT failures
Format NACKs, routing issues, and business-level rejects on SWIFT — distinct lifecycle stages.
- SWIFT error codes overview— NACK, routing, business rejects
- SWIFT NACK — format error
- Intermediary routing failure
SEPA returns
Scheme reason codes (e.g. R01, R02) and when the debtor or beneficiary bank returns a payment.
Stuck payments & SLA
Payments that never reach a final status in time, or breach internal or corridor SLAs.
- Stuck payment detection
- SLA breach monitoring
- pacs.002 status codes— ACSP vs ACSC vs RJCT vs PDNG
Preflight
Detect failures before execution and investigate outcomes after — same control plane for sandbox and demos.
Preflight is a pre-execution and post-execution control layer for payments.
Preflight models these scenarios deterministically before and after execution.