How to add an existing account to a new plan?
My friend is already on an Unlimited&More plan with just 1 line, himself. Thus, he already has an AT&T SIM card and number.
My two other friends and I aren't on any AT&T plan yet, but we intend to buy an Unlimited&More plan as well. The three of us need new physical AT&T SIM cards. My first friend wants to join this plan because per person wise, 4 lines is cheaper than 3 or 1.
On the website, I selected the plan, and added 3 AT&T Universal SIM Cards to the cart for me and the two other friends. I'm having trouble adding the first friend who is already with AT&T though. I tried "See if you can keep your current number," but it said he can't even though his number is from AT&T and on the same plan. That leaves me to choose "I already have a SIM or eSIM card," as he does not want a new SIM card. This requires his SIM Card ID and IMEI. Is this how it's supposed to be? Once he provides that information, and the plan begins, can he keep his current SIM card as part of the new plan with 4 lines?