To offer completely automated credit card processing, a merchant gateway must support the following 4 types of transactions:
Most credit card charges involve only the CHARGE transaction. An exception is domain registration, which involves two steps:
1. Lock required amount on the credit card (AUTHORIZE) before domain registration
2.a. If domain registration succeeds, debit the locked amount to the credit card (CAPTURE)
2.b. If domain registration fails, unlock the amount and cancel the initiated transaction (VOID)
Some merchant gateways don't support CAPTURE or VOID transactions, requiring that they be performed manually through a web interface. In case of domain registration, you will receive email notifications requesting to complete or cancel a transaction every time a user registers a domain name.