Cellular didn’t transfer to new phone

I understand that your Cellular Service did not transfer from your old iPhone to your new iPhone. Can you remove the SIM card from your old iPhone and install it in your new iPhone 13 Pro Max? The active cellular service is probably still on the SIM card that is still in your old iPhone. You can double check this by attempting to make a call from your old iPhone. If you can, then the active SIM is still in your old iPhone. If all else fails, then contact your carrier.

Axel F.

Yes, SIM=Subscriber Identity Module, it contains the information that your carrier needs to provide service to your phone. You can either transfer the SIM to your new phone, or contact your carrier’s tech support to have them activate the eSIM capability of your phone.

Does this mean I need to put the old SIM card into my new phone? I’m confused