What Does It Mean When It Says "iPhone Unlocked?"

By David Ward

Updated September 28, 2017

Unlocked iPhones can be used on any GSM network, including many non-US mobile networks.
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When an iPhone is unlocked, you can use it on more than one network using Global System for Mobile Communication technology. For example, an unlocked iPhone can be used on T-Mobile, AT&T and any number of non-U.S. carriers using GSM networks. Apple has begun selling "unlocked" iPhones in its own stores. However, an additional level of security prevents iPhone users from using applications not available within its own application store. For this reason, some users only consider an iPhone fully unlocked when this restriction is removed. The process of removing this restriction is sometimes referred to as "jailbreaking" the iPhone.

Unlocking an iPhone for Use on Multiple Networks

Like most cellphones sold in the United States, an iPhone is typically locked to a single network. Currently, you can buy it through AT&T and Verizon Wireless. The ability to use the phone on other carriers is one of the common reasons that cellphone users will buy an unlocked phone. An unlocked iPhone can be used on any GSM network, which includes AT&T, T-Mobile, and many foreign cell phone networks. Unlocking an iPhone allows the user traveling abroad to purchase a SIM card for the country in which he or she is traveling and connect the phone to a GSM network in that country. Not only can this reduce roaming fees, but it gives the user a local number in that country, which can be especially useful for business travelers.


Two primary technologies are used in cellphone networks, GSM and "Code Division Multiple Access." In GSM networks, the handset uses a SIM card, a small electronic card that contains information about the phone and connects it to the network. The unlocked iPhone is a GSM phone. CDMA phones, on the other hand, are connected to a network through a program embedded within the phone. CDMA phones are much harder to unlock, and many consider the difficulty of unlocking a CDMA phone to be prohibitive to unlocking the phone. Verizon Wireless uses a CDMA network, and for this reason, many people consider the Verizon iPhone to be tethered to Verizon.

Unlocking an iPhone

While the process of unlocking an iPhone is legal, Apple has been very clear that unlocking an iPhone that was not originally sold as unlocked voids the warranty on the phone. Nevertheless, services are available that unlock GSM iPhones bought through AT&T. This allows the iPhone user to take the phone abroad and use a SIM card from another carrier.

Unlocking Versus Jailbreaking

An iPhone may be considered "unlocked" if it can be used on any GSM network. However, Apple has restricted the iPhone to only being able to access programs available through the Apple "app store." Thus, many iPhone users have chosen to additionally bypass this restriction, a process often referred to as "jailbreaking" the iPhone. Many companies offer services to jailbreak the iPhone. However, as with using a third-party unlocking program, it should be noted that jailbreaking the iPhone will void the warranty. In addition, some users report software bugs after going through this process. However, for those who wish to unlock all the features possible on the iPhone, jailbreaking the phone will unlock additional applications and allow the user to attach the phone to any GSM network, allowing the iPhone to be used with all the features available on other GSM phones.