Prepaid phone on postpaid account

Sure, you can use any compatible phone. Just realize that usage on postpaid will not count toward getting the phone unlocked. A prepaid phone requires 6 months of usage on prepaid service to be unlocked.

Thank you. Got it done. No need to unlock anyway. 

Hi there @travel2207, we are happy that your services are still with AT&T.

Thanks for providing that wonderful information @sandblaster, about our Prepaid compatible devices.  

We are glad that your services was able to be completed with the SIM card.

Thank you for reaching out to our Forums.

Ashley, AT&T Community Specialist