How to Activate a Micro SIM
- 1). Open the Web browser on your computer and go to the AT&T Activate Your Phone site at Wireless.att.com.
- 2). Select the option to upgrade your phone.
- 3). Enter your phone number and select a verification method from the drop-down box. You can use your ZIP code or the last four digits of your social security or tax ID number. Enter the code and click "Next."
- 4). Locate the SIM card number on the plastic card in which the micro SIM is embedded. The number is 16 digits and starts with 89.
- 5). Enter the micro SIM card number in the SIM card number field and click "Activate."
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