Apple appears to be shipping cases separately than the iPhone X -- with some reports seeing expected deliveries of the protective enclosures more than a month before the sought-after OLED phone arrives.
With the expected heavy demand for the iPhone X, ship times have slipped far into December. Given that Apple doesn't charge credit cards on file until the shipment process reaches the preparation phase, customers are likely to see multiple charges potentially a month apart.
A large hold on a credit card will in all likelihood be charged for the case worth a small fraction of the selling price first, with the larger charge being a different line-item later when the iPhone X is ready to ship.
AppleInsider reached out to several banking institutions with them mostly saying that if customers have an existing relationship with Apple that the gap in charges will likely pose no problem. However, we were advised that if there is not that history, that customers should contact a support representative at the bank in question to tell them that a second charge associated with the transaction is coming later in the month to ensure that there are no problems that would potentially hold up delivery.
The Equifax data breach, and enhanced transaction security implemented in the wake of the hack were reasons we were given for potential problems with the small amount being posted in place of the large initial approval, and a later charge of the iPhone X sale price.
We were also told that users who used Apple Pay to execute the transaction shouldn't see any problem.