ReverseLastTransaction Method

Used to reverse/void a previous transaction.

Syntax

[VB.NET]
Public Sub ReverseLastTransaction()

[C#]
public void ReverseLastTransaction();

Remarks

This method is used to reverse a previous transaction in the case a response was not received from the host or to void a previous Sale or Credit transaction.

A Timeout Reversal is needed when a terminal initiates a debit transaction (Sale or Credit) to the FDMS host, but the host fails to send a response back to the terminal for any reason. If a transaction times out or you receive a network connectivity error, you should immediately call ReverseLastTransaction. In this situation you don't know whether the host received the request and the response back to you was lost, or if the host ever received the request at all. Therefore the ReverseLastTransaction method can used to reverse the last transaction sent by this component. You must not change any properties (or fields of properties) or call any other methods (including Reset), as ReverseLastTransaction operates based on the current state of the component.

First Data will always send an ApprovalCode of "AP888888" or "AP868686" on a reversal response, and the CaptureFlag value will be False. First Data does not check whether the original transaction occurred or not.

If you do not receive a response to the reversal (eg, it also times out), you must continue to call ReverseLastTransaction until you do receive a response.

Note: A Debit Reversal must not be used by the merchant as a way to credit a customer for returned merchandise.

Important Note: You must ping your list of service provider URLs and update the URL property to the service provider with the shortest response time every 100 transactions, as well as when your application initially starts. This is not a normal ICMP ping - to determine the fastest transaction URL you must use the special Ping method inside the FDMSRegister component. (You may update your list of service provider URLs with the FDMSRegister component's ServiceDiscovery method).