Sprint confirmed that, starting Friday, all new iPhone 4S models sold for use on its network will initially be carrier-locked to Sprint's designated overseas partners when using the phone outside the United States. After a few months, however, customers in good standing can request an unlock so that they can use cheaper prepaid Micro-SIM cards overseas, Sprint says.
[ InfoWorld's Galen Gruman details the iPhone 4S's "worldphone trap." | iPhone, BlackBerry, or Android? Whatever handheld you use or manage, turn to InfoWorld for the latest developments. Subscribe to InfoWorld's Mobilize newsletter today. ]
The iPhone 4S's status as a "worldphone" gives it some unique properties compared to past iPhones, at least when operating on the Sprint and Verizon networks. Those networks use the CDMA standard, rather than the rival GSM standard used throughout the world (and by U.S. carriers AT&T and T-Mobile).
Because the iPhone 4S supports both GSM and CDMA, Sprint and Verizon customers can to travel to countries without CDMA networks (which is to say, most countries) and still get a signal by using GSM instead. (By contrast, AT&T customers traveling to countries with CDMA networks cannot use such networks.) iPhone 4S models sold on those carriers come with a Micro-SIM card (the hardware that allows a phone to identify itself to a GSM network) that's tied back to their U.S. account.
If you travel overseas and have international roaming enabled, the Sprint and Verizon iPhone 4S can switch to GSM and work normally; an AT&T iPhone 4S uses GSM abroad. However, international voice and data roaming charges, which are much higher than your typical monthly bill, will show up on your statement when you get home. If you limit your overseas usage and don't travel much -- which probably applies to most people -- it's not that big a deal.
Savvy international travelers who spend a lot of time abroad know that you can save a lot of money by skipping out on the roaming charges and buying a prepaid Micro-SIM card in-country instead. The problem is that, by default, you can't put those cards in an iPhone 4S and have them work, because the device is "locked" to the Micro-SIM card that's tied to your carrier back home.
Sprint's new policy
As we reported when the iPhone 4S arrived, Verizon and Sprint will allow users to unlock the Micro-SIM slot on their iPhones after a certain amount of time. Verizon says that the company will do this by request for any customer in good standing who has had their iPhone 4S for at least 60 days.
Sprint's story was a little more complicated. Sprint's initial batch of iPhone 4Ses shipped with the Micro-SIM slot completely unlocked, though the company issued a statement shortly afterward clarifying that future iPhone 4Ses would be locked, but would be unlocked to customers in good standing on request.