I was wondering how can I ask a user for credit card details and charge him without using Apple's in-app purchasing mechanism.
My idea was to post the user's credit card to my online credit billing system and make the transaction on the website, behind the scenes, and then report back to the user with the transaction results.
Will Apple approve this kind of app?
Apple will not approve such an app, unless users are purchasing something which cannot be purchased via an in-app purchase.
For example, a pizza store is allowed to collect credit card details to pay for pizza's. But a digital music purchase must use the in-app purchase system.
From apple's documentation:
There are four supported kinds of products that you may sell using In-App Purchase:
- Content includes digital books, magazines, photos, artwork, game levels, game characters, and other digital content that can be delivered within your application.
- Functionality products unlock or expand features you’ve already delivered in your application. For example, you could ship a game with multiple smaller games that could be purchased by the user.
- Services allow your application to charge users for one-time services, such as voice transcription. Each time the service is used is a separate purchase.
- Subscriptions provide access to content or services on an extended basis. For example, your application might offer monthly access to financial information or to an online game portal.
Anything in that list must use the in-app purchase system, and anything else must not use it.
By the way, these things have changed many times, and could change at any time in future.