Authorize.Net Virtual Point of Sale : Using VPOS : Capturing an Authorize Only Transaction
 
Capturing an Authorize Only Transaction
If you have the transaction ID for an Authorize Only transaction, select the Prior Authorization Capture option, and enter the transaction ID. Authorize.Net will change the status of the transaction from Authorize Only to Captured Pending Settlement, and we will now settle the amount automatically after your daily Transaction Cut-Off Time.
You may also log into the Merchant Interface and capture the transaction from the Unsettled Transactions page.