Change from a PREPAID plan to a non-PREPAID wireless plan

To move your number from prepaid to postpaid, you must go to an ATT corporate store. Yes, you will get a new SIM card. Be aware that you still won’t be able to roam internationally for 60 days.

We'll be happy to guide you through this process @froriha.

As @sandblaster informed you, you will need to go to one of our corporate locations (these are the stores that are not specifically indicated as 'Authorized Retailers' in our directory) and you will need a new SIM card. Additionally, you'll have a credit check and if you keep the same phone number, any remaining balance on your prepaid account will be applied to your postpaid account.

You can find more information regarding switching your service here; if you have any additional questions or concerns, please don't hesitate to reach and we'll be happy to guide you further. Thank you for reaching out to our community.

Darais, AT&T Community Specialist 

Hi, @sandblaster . Thank you for your answer! So, do you mean that I can only start roaming internationally 60days after I get my new SIM card?

@froriha

To confirm the above, yes, no roaming for 60 days.