Any payment with status Settled can be refunded via this endpoint.
To cancel a payment within the void window (prior to the CanVoidUntil), call the Void Payment endpoint.
If the payment is past the void window, you must wait until payment is in status Settled to refund the payment

The refund call results in the following actions:

The Status of the original transaction is changed to Reversed (shown as "Refunded" in the UI).
A new credit (negative) transaction is created with a Status of:
Authorized for Credit Card refunds
ReversePosted for ACH refunds (shown as "Refund (Posted)" in the UI)
The ReferenceId field for the original transaction is set to the Payment Id of the credit transaction.
The ReferenceId field for the credit transaction is set to the Payment Id of the original transaction.

Testing Refunds in Sandbox

To test a refund works in Sandbox, you must have a payment in status Settled. You may either wait 3 business days for the system to mark it as settled, or call the following endpoint to mark the payment as Settled manually. This endpoint works only in theSandbox Environment.

PUT v4/MarkPaymentStatus
{
	"PaymentId" : 123545 // The PaymentId of the payment to mark as Settled
}