When you buy a new phone from AT&T Wireless, your eSIM or SIM card is set up and activated. However, when you switch to AT&T and bring your existing phone, you must activate your new SIM card ...

For T-Mobile it’s 40 days, while AT&T and Verizon ... the original SIM, you’ll need to reset the phone before it can be unlocked. Power down the phone, then replace the old SIM card with ...

A physical SIM card is essentially a tiny card with a chip that connects your phone to your wireless carrier. It contains ...