New iphone
I have bought my wife a new iPhone and I am going to use her old one. However I cannot unlink the two phones. How can I do this without my wife’s new phone losing all her stored data.
iPhone 8, iOS 14
Question marked as
She should backup her phone by her chosen method.
Two choices then:
1 Set up the new phone with her apple ID then restore to the new phone from that backup.
or
2 keep old and new phones side by side and she can transfer the information, using Quick Start. That requires the new phone in factory fresh condition
Use Quick Start to transfer data to a new iPhone, iPad, or iPod touch - Apple Support
When you are happy the data has been transferred you should reset the old phone to factory settings and you set it up as new with YOUR (different) iApple ID
It is a very bad idea for different people to share the same Apple ID
You can share valuable assets using family sharing
Backup and restore info
(1) How to back up your iPhone, iPad, and iPod touch – Apple Support
(2) Restore your iPhone, iPad, or iPod to factory settings – Apple Support