How to transfer contacts to a new Apple ID
Can I transfer all contacts from one Apple ID to another?
iPhone 11, iOS 14
Question marked as
If the contacts are saved on iCloud:
Export first
Export a contact as a vCard on iCloud.com - Apple Support
Then import
Import a contact on iCloud.com - Apple Support
If the contacts are saved on an email account. you can just add that again with the new apple ID.
Good luck!