Apple has introduced yet another way for users to pay for items in iTunes shopping carts. It's called iTunes Pass and it amounts to having prepaid credit on an iTunes account.

The new feature implements Passbook, allowing users to deposit credit that can be used for content. The whole process involves visiting the nearest brick and mortar Apple Store location so you can refill an iTunes account by buying credit in the store.

According to reports, iTunes Pass is a service in which an Apple Store employee scans codes generated by iTunes Pass to fulfill the purchase. The money deposited is available for the user to spend instantly.

It could be that Apple wants to eliminate the costly process of manufacturing tangible, plastic gift cards. It might not like keeping track of a bunch of tracking codes for credit, either.

It might also add a layer of security to online purchasing because it would conceivably eliminate the need to use a debit or credit card for purchases made by each individual user.

Apple seems to be stepping more into the realm of online payment systems. Passbook was its first real breakthrough in payment processing, but the company is likely looking to expand upon its services. It has so far yielded little to discuss since 2012. Passbook keeps airline boarding passes, movie tickets, and gift cards all in one place, and users can scan their iPhone or iPod Touch to check in for a flight or redeem a coupon.

As one source notes, the new service is only available in Japan for the time being. It is likely that Apple may choose a test market before releasing the service in the United States and worldwide.

There seems to be speculation that the company could roll out the new service in the U.S. by the end of the year, but Apple has not confirmed this. The company did reportedly state that iTunes Pass is not available in China, Brazil or Turkey. It could be possible that Apple will release the service in some other countries after some successful testing in Japan, but that remains to be seen.

The service is essentially the opposite of Passbook, which takes money out of users' accounts after they purchase loyalty cards with codes. The iTunes Pass service makes deposits.

Another source noted that the payment system iTunes Pass should not be confused with the iTunes Pass, which allows users of the iTunes Store to pay for content based on specific musical artists. That service would be more similar to a subscription model like Spotify.

Apple only has a limited number of stores in Japan, making it ideal to test the service, sources say.