old phone

Understood. My favorite way to ERASE everything on an iPhone and reset it to factory settings is :

Open Settings ➔ General ➔ Reset ➔ Erase All Content & Settings : This should do what you have set out to do. This action WILL NOT affect anything on your new iPhone.

Axel F.

Once you have transferred the data using the Quick Start method then both iPhones should have automatically returned to their normal operating screens which would allow you to carry on as usual. Is your old frozen or stuck on a screen that you cannot get out of?

Axel F.