A new customer needs to activate the SIM card by using their SIM card number. SIM card number is very important for activation. You can get the number from the package of your phone. The number will be printed on the package on a white label with bar codes. You will find 'ICCID' printed over the label that follows a long number. This long number is your SIM card number needed to activate AT&T SIM card phones.
However, in case you do not have the package, you need not worry. You can get your SIM card number by carrying noting down the number that starts with 89 on the back of your SIM card.
Visit the AT&T retail store and meet a representative. He/she will activate your SIM card in-person or through phone with the help of you account information. You will be asked to provide your SIM card number as it holds all your account details. You need to place the SIM card into your phone and turn it on. You will find your AT&T SIM card activation to be successful.
If you do not wish to make a trip to customer care center, you can visit the AT&T website. Once on the site,
- Visit the my Wireless Account page.
- Navigate to 'Activate Your Phone' page.
- Fill in the details and click on 'Next'.
- Follow the instructions carefully and keep your SIM card number handy
- Fill in the number when asked and verify
- Your SIM card will be activated.
In case of replacement, you will need to call the customer care center for AT&T and request them to set you up with a new SIM.