Once a transaction has been processed, you cannot cancel it. This goes for sales and captures, for example, and also rebills, which are already done, and cheque collections as well. In those cases, you would need to provide a refund if you wanted to dissolve the transaction.
But for authorization transactions, there may still be time to act. You can cancel an authorization before those funds are captured, thus dissolving the sale before it occurs, and negating the need for a refund.
But please be careful: Please check if your authorization has already resulted in a capture. This is explained below.
To cancel an authorization:
First, find the authorization you need to cancel. Go to the Processing tab and click Transactions.
Use the filters on the left to find the authorization. Click the View button to open it.
Before you go any further, check if the authorization has already resulted in a capture. Go to the Related transactions tab:
Check to make sure the transaction has not already been captured. We can only properly cancel an authorization if the capture has not been processed yet. Otherwise, we will receive an error.
Now go to the Operations tab. Notice the Cancel area:
Double-check that the amount of the authorization is correct, and click the Cancel button. A pop-up from your browser will ask you to confirm.
A progress bar will appear, after which you should receive a success message.
When you cancel an authorization that has not been captured, the capture operation tied to that authorization will not be processed. Your customer may still see authorization/cancelation activity on his or her statement, however. (This will depend on the card-issuing bank.)