The outage vexed the iPhone and iPad maker for more than five hours, disrupting some of the world's most widely used and profitable services and frustrating millions of music lovers and mobile device owners around the world.
Access came back in the late afternoon, Eastern time, according to status updates posted by Apple Inc. While they were locked out, exasperated Apple users vented in social media and online forums.
Apple apologized for the inconvenience, blaming the problem on an internal error that bogged down its computer servers.
About 800 million accounts with credit cards linked to them have been set up on Apple's iTunes store since it opened in 2003 to sell digital music for the company's iPods.
More than 75 billion apps have been downloaded from the store that Apple opened in 2008 for the iPhone and, later, the iPad. Many of those apps charge a fee, or generate revenue from purchases of other services while people are using the program.
Apple's online book store and the app store for its Mac computers weren't working either.
Last year, Apple's revenue from its iTunes, mobile app store, iBook, Mac app stores and other services totalled $18.5 billion, or an average of $50 million per day. That's still a small fraction of Apple's total revenue of $200 billion during that period.
The outages also cut into the income of mobile app developers who keep most of the revenue from the programs sold in the app store. Last year alone, Apple distributed $10 billion to mobile app developers, an average of about $27 million per day.
The global outage comes two day after the Cupertino, California, company unveiled its latest gadget, the Apple Watch.
Apple is hoping to attract even more traffic to its app store next month when the smart watch goes on sale.
The company's stock slipped $2.27 to close at $122.24. The shares have repeatedly hit new highs this year.