Getting my iPhone 15 Pro delivered today...

Use the Quick Start method detailed in this link and your phone number will automatically port over to your new phone --> Use Quick Start to transfer data to a new iPhone or iPad - Apple Support

Note that if the “normal” procedure described by Lobsterghost1 fails; don’t panic or think that you did something wrong.

There are a lot of “back office” functions within your carrier’s infrastructure which must work perfectly for the transfer to work. Sometimes they don’t work so perfectly.

If there’s a problem … just call your carrier, preferably from an entirely different line … and they’ll complete the transfer in short-order.

You're welcome and Chattanoogan provided good advice about calling your carrier if the number doesn't port over. It has for me on every iPhone I've set up using Quick Start.

I’m batting about 0.670 on Quick Start eSIM success w/o carrier assist.

Guess I'm lucky. Since the dawn of eSim and getting a new iPhone every year, my record is 100%.

Glad you got it up and running and everything is performing as you hoped. I love my 15 Pro Max!

Good to hear !!!