I just ordered a new phone. It won't be here for a week or so. Then I went to my wireless provider to buy a new SIM so it would be here by the time my new phone was (the new phone needs a different SIM size than my current one so I can't just swap it out).

I know the new phone is compatible with my provider and it is unlocked so everything is good. But they asked for my new phone's IMEI number to make sure, and then that number was listed on my SIM order. Since I don't have it yet and I know it is compatible, can I just enter an old phone's IMEI and then correct things later if necessary, or does it really need my new phone's IMEI?

Thanks!

Found this: https://www.howardforums.com/showthread.php/1850823-Why-Do-They-Need-A-Phone-s-IMEI-When-Activating-Service

"The IMEI is for the initial activation, it links the SIM to the phone. Once the initial activation is complete you can swap out phones at your own discretion."

Doesn't exactly answer your question, except you may not be able to active your (first) phone without it.

Thanks!