Using eSim in Iphone 11

That would be a question for your cellular carrier if you are planning on using the same one for the additional line.

In general, yes each line would incur an additional cost as it would be a different and independent service plan.

eSIM gives you a way to use an additional line on your iPhone. This is way one number/line can be your eSIM and the other number/line can be on your physical (regular) SIM. The idea is to be able to carry one phone vs carrying two. Once you move a number from another one as an eSIM on your current iPhone then your other phone will not work with the phone number that it once had because that would have been transferred to your eSIM. You can then, if you choose to, give that phone away or buy a third line on it. In the end you will only be paying for two lines because you have only retained two lines.

Axel F.