Originally Posted by
Need
When you took out your AT&T sim card, you just let it sit somewhere and not putting it in another phone right? There should be no activities on the line (voice or data or txt) on the days that you took the sim card out. Now if the data activities started after you put the SIM in...it could be you have pending messages.. maybe with pictures or video waiting for you and you don't have WiFi when you put the SIM back in? Or a software update push by AT&T?
Correct. The SIM sat outside of the phone until I returned on both trips. When traveling used the T-Mobile SIM to make calls but mostly for data.