How does iPhone import SIM card address book and number in SMS?

Import the address book from the SIM card into the iPhone.

Import the address book stored on the SIM card.

If your iPhone doesn't use the SIM card on your old phone:

Make sure that the SIM card on the old phone can be inserted into the iPhone.

Take out your iPhone SIM card and replace it with the SIM card of your old phone.

Tap settings > address book > import SIM card address book.

Wait for the import process to complete.

If you replaced the SIM card in step 1, please take out the SIM card and replace it with your iPhone SIM card.

Open Address Book and make sure the address book has been imported.