Thank you for contacting AT&T Customer Care about unlocking your iPhone
1846.
We are unable to complete your request at this time due to the following reason:
The unlock code for this device is unavailable due to security restrictions based on the device's history. You may want to return the device and/or provide feedback to the seller.
Please note, if you are traveling internationally, iPhone is a quad-band phone and will work in many countries across the globe. Please visit www.wireless.att.com/learn/international/ for information on traveling abroad with iPhone.