You can activate your AT&T SIM in-store, online, or by contacting customer service. The process is similar for postpaid and AT&T prepaid customers.

Compatible with most AT&T Prepaid mobile phones Redeemable for talk time, text messaging, games and other AT&T Prepaid services $65 value ...

When it comes to finding a prepaid phone plan, traditional carriers like AT&T, Verizon and T-Mobile aren't your only options. Here are our picks for the best prepaid phone plans this holiday season.