Cingular (now AT&T) SIM cards are required to access wireless phone service with the provider. In addition to allowing voice and data service, the SIM cards provide users with a great deal of flexibility and worldwide roaming capabilities.

Benefits

AT&T SIM cards are equipped with the Global Systems for Mobile (GSM) technology which is compatible throughout the world. AT&T SIM cards provide extensive coverage in United States and international roaming in more than 200 countries.

Transference

AT&T SIM cards allow users to change phones very easily. Unlike CDMA technology, which requires users to contact customer service or go into a company-owned store when they want to transfer phones, AT&T users can simply remove their SIM card and install it in the AT&T phone of their choice.

Phone Book

Phone book/contact information can be stored directly to the SIM card. Therefore, when users change cell phones, they do not have to import their contacts manually; the SIM will load the contacts for them.

3-G Broadband

AT&T SIM cards provide users with access to high-speed, 3G broadband Internet access at any time. Subscribers can check email, browse the Internet, download music, ringtones and video clips, and use GPS technology for maps and directions.

iPhone

AT&T SIM cards allow users to access the Apple iPhone, since the iPhone is only available on the AT&T network in the U.S.

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Why AT&T

GSM Coverage Maps