The iPhone 4S adds a new wrinkle to the mix. There are now wireless partners offering the phone-- joins previous iPhone 4 carriers and to provide service for the 4S model.
The iPhone 4S becomes available on October 14, with preorders beginning Friday. A 16GB iPhone 4S costs $199, while the 32GB model sells for $299 and a 64GB phone will set you back $399. Those prices assume you'll sign a two-year contract with one of the three carriers mentioned above, however--and that you're eligible to get a phone at that subsidized price.
Generally speaking, once you sign your two-year contract for phone service with a carrier, you're locked into that piece of hardware for the duration. You can check your eligibility with your carrier--more on that in a moment--but Apple offers an easier way. , type in a few details about your account, and you'll quickly see when you are eligible for an upgrade, along with what price you'd pay if you choose to upgrade early instead.
At AT&T, you can be eligible for an "early upgrade" as little as a year into your last contract if . There are four ways to check your eligibility: You can dial *639# into your iPhone; you can go to and enter your account information; you can call the company's customer service line at 1-800-331-0500; or you can in your area. AT&T told that it expected to release a new AT&T Upgrader App this week that would let users check their eligibility and pre-order the new phone starting Friday; as this article was published, the Upgrader app had not been added to the App Store, however.
If you own an iPhone 4 with Verizon, you're not eligible for an upgrade--at least not at the subsidized prices of $199 for the basic 16 GB model. Verizon has been selling the iPhone only since February, which means that its Apple-loving customers haven't finished one year on their two-year contract. If you use Verizon's service for another smartphone but want to jump over to the iPhone 4S, you can check your upgrade eligibility at .
Since Sprint is new to the iPhone game, there are no existing iPhone customers with that carrier. But if you own another phone through Sprint, you can check your upgrade eligibility through the . Sprint requires that it be 20 months since your last contract started before you're eligible for the upgrade.
(While Sprint won't take preorders for the iPhone 4S until Friday, bargain hunters can get their hands on a $99 iPhone through the carrier right now-- on Thursday.)
AT&T charges a one-time fee of $18 to upgrade your phone; Verizon doesn't charge a fee to upgrade phones after a contract has been completed, but does charge a one-time $35 activation fee for new service.
If you're in the middle of a contract, it's a costly proposition. If you purchased an iPhone with AT&T and want to leave the contract early, The same situation at Verizon results , minus $10 per completed month of contract. Leaving Sprint early--if you've purchased an "advanced device" as part of the contract--.
Because the iPhone 4S is a world phone--meaning a single model is compatible with both GSM and CDMA networks--one might assume that you'll be able to easily switch carriers at the end of your contract while keeping your current hardware. One would assume incorrectly: Apple's fine print on the iPhone 4S warns that "the iPhone model you purchase is subject to your wireless service provider's policies, which may include restrictions on switching service providers and roaming, even after conclusion of any required minimum service contract."
The list price of $199 for the basic 16 GB model is actually a "subsidized" price--it assumes you'll sign a new two-year contract with a wireless phone carrier. If you want to upgrade your iPhone before reaching upgrade eligibility, you can always pay the unsubsidized cost. And how much is that? Tough to say. Apple announced of the iPhone 4S at its Tuesday event. So it's worth noting that the unsubsidized cost of a 16 GB iPhone 4 was, at the time of its release, $599. If you want the new phone and you're not eligible for an upgrade, you'll probably have to pay a steep cost.
Apple offers a in which you can get credit in the form of an Apple gift card in exchange for your "gently used" smartphone. Wireless carriers have their own programs as well. lets you get an online appraisal on your current phone; the company will pay you that value in the form of a Verizon gift card. AT&T, meanwhile, has its own program--that company asks you to bring your old phone to one of its stores.
We go into greater detail on elsewhere on Macworld.com.