Identify the settled payment order that needs reversal and confirm the settlement date and effective date in Modern Treasury
Create a reversal object via the POST /payment_orders/{id}/reversals endpoint specifying the reason for the reversal
Modern Treasury will originate a return entry (CCD or PPD debit) against the settled credit; confirm the reversal object status transitions from pending to submitted
Monitor the reversal for its own return risk: the originating bank can reject the reversal if the account has since been closed or if the reversal window has passed
Update your internal ledger to reflect the reversed credit and reconcile against the Modern Treasury ledger transaction object
Notify the downstream recipient of the reversal and trigger any required customer communication
Known gotchas
ACH credit reversals must be originated within 5 banking days of the settlement date; reversals attempted after this window may be rejected by the RDFI
The reversal creates a new debit entry that itself can be returned; design your state machine to handle a returned reversal as a separate case from a successful one
Modern Treasury reversals consume ACH origination capacity; plan for the offsetting debit when calculating available credit origination headroom
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp