How to Activate a Micro SIM

By Mandy Slake

A micro SIM card is the identification chip used by the Apple iPhone 4 and the iPad. Before you can use the card to activate your Apple device, you must first activate it on your carrier's network. You only need to activate an iPhone or iPad in the United States if you use AT&T's network, since Verizon Wireless devices do not use SIM cards.

Step 1

Open the Web browser on your computer and go to the AT&T Activate Your Phone site at

Step 2

Select the option to upgrade your phone.

Step 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."

Step 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.

Step 5

Enter the micro SIM card number in the SIM card number field and click "Activate."

Tips & Warnings

  • If you are having issues with activating the micro SIM on the website, contact AT&T at 800-331-0500.