Does the "Add device to account" upgrade work as I think it does?

[Benjamin3]

I have a SIM Only plan right now, but i've been looking into getting a new phone and I saw the option to "Add this device to my account".

The way I have it as I think it works in my head goes as follows. I keep my current SIM plan, and simply add whatever phone I want to my plan, and pay the extra amount that comes with that phone on top of my current SIM Only plan. My SIM plan doesn't get cancelled and I don't need to pay off that SIM contract.

I know this may sound silly but I have quite literally never done anything like this before, so I just want to make sure that the idea in my head actually is what I think it is.

Thank you.

[XRaySpeX]

No, it doesn't! It would be an entirely new line & no. with its own plan on top of your existing SIM-Only plan.

What you want is an upgrade to your existing SIM-Only contract where you would replace it with a new phone contract & plan on your existing no. provided you are currently eligible for an upgrade.