Apart from Digi, both Celcom and U Mobile are also offering direct billing for purchases on the Apple App Store and services. This allows you to pay for apps, music, movies and even iCloud storage using your prepaid credit or have it charged directly to your postpaid bill.
The carrier billing option is applicable to both Postpaid and Prepaid users, and you can enable this under your Apple ID settings. Under Payment Type, just select Mobile Phone and then confirm using a verification code that’s sent to your mobile number.
On U Mobile, there’s a purchase limit of RM400 each month for both postpaid and prepaid. So far there’s no mention of any limit on Celcom but Digi does limit its postpaid purchase at RM500 for every 30 days.