You are shipping the item before the customer’s card is FORMALLY charged, not before their card is verified.
There are two parts to any successful credit card transaction:
The Authorization – This is where we verify the CVV code, address and phone number, and ensure that the card is good for the amount required to complete the transaction. If it is, we put an authorization out that puts a hold on those funds and reserves them for us. This happens instantly, when the customer checks out.
The Charge – This is where we turn the authorization into a formal charge, and the charge actually appears on the customer’s statement. We put the charge through when you mark the item as shipped (or instantly, if the product is electronically delivered or otherwise provided to the customer instantaneously).
If the original authorization expires before you are able to mark the order as shipped, you will need to reauthorize the amount from the Mark Shipping area of your Account Homepage.

