How to activate your AT&T prepaid card After you install your SIM card or download your eSIM by scanning the QR code, AT&T sends a text message ... easy to default to one of the Big Three carriers ...

I've been a Verizon and T-Mobile customer ... re unlocked and eSIM compatible. To sign up for AT&T's free trial, download the MyAT&T app from Apple's App Store or scan the QR code at AT&T's ...