Several U.S. cell phone carriers carry the BlackBerry line of smartphone devices. Each device uses the BlackBerry operating system developed by RIM that allows users to manage their e-mail and other online connections while on the go. The type of SIM cards used in these devices, however, varies depending on the cell phone carrier the device is tethered to, with some BlackBerry devices not using SIM cards at all.
BlackBerrys and other phones that are tethered to a Global System for Mobile Communication (GSM) network use SIM cards to store the user's information. In the United States, AT&T and T-Mobile both use GSM technology, so any BlackBerry device bought for use on one of these two networks would require the use of a SIM card. GSM BlackBerrys are carrier-locked, however, meaning that a BlackBerry device that uses an AT&T SIM card cannot use a T-Mobile SIM card and vice-versa.
The exception to the rule of carrier-locked BlackBerrys comes in the form of an unlocked BlackBerry device. Unlocked devices can be used with a SIM card from any GSM carrier, regardless of which carrier the device was purchased for use on. For example, T-Mobile will provide customers with at least 40 days of active service with an unlock code that will allow their device to be used with other GSM network SIM cards. Unlocked BlackBerry devices, then, can use any type of SIM card, regardless of carrier.
The other main type of cell phone network in the United States is the Code Division Multiple Access (CDMA) network. U.S. cell phone providers Sprint, Verizon, MetroPCS and U.S. Cellular all use CDMA technology, which does not use SIM cards to store the user's information. Any BlackBerry bought on a CDMA network, then, cannot use any type of SIM card.
SIM Card Location and Identification
To determine what type of SIM card is currently in your GSM BlackBerry device, open the BlackBerry's battery compartment cover and remove the battery to reveal the SIM card's location. Gently slide the SIM card out of its slot to determine what type of SIM card is in your device. If the SIM card has a pink "T" on it, it's a T-Mobile SIM card. If the SIM card has the AT&T blue globe logo or a small fireball logo on it, it is an AT&T SIM card.