Reverses a paid ACH credit payment whose parent is a payroll_item or contractor_payment. Use this when net pay was sent to the wrong account or should be undone as part of a correction workflow.

Provide a reason in the request body. Partners may send one of:

• duplicate
• incorrect_amount
• incorrect_receiving_account

The endpoint requires the payment:reverse OAuth scope (in addition to payments:write) and an X-Idempotency-Key header. Reusing the same key returns the first response without reversing again.

We recommend relying on the Payment object's can_reverse field to determine whether a reversal is possible, and on reversal_deadline for the last time a reversal can be requested.

On success, the response is the updated Payment object (for example, status may move to reversal_processing). If the payment cannot be reversed, the API returns 400 with error type payment_ineligible_for_reversal.