Users logging on to the online Apple Store at midnight as the iPhones went on sale reported slow load times, and a lengthy delay in the devices becoming available.
Some service appears to have been restored after about 30 minutes. But this morning, the store was down for some users. Its availability appears to be intermittent.
Some customers reported that the iPhone was available on carrier websites and the Apple Store app, but not the desktop site. There were reports that the iPhone 6 had sold out through some carriers.
The delays in the iPhone 6 becoming available in the online store frustrated many customers, as they had waited until the early hours of the morning to order the new phone.