Change iOS account on iPhone without losing data For my company I had to create an Apple ID to publish our app. I am the one with an iPhone for personal use and I have an Apple ID for private use. I do not want this Apple ID to be affiliated with my companies. 

For the enrollment process of an App Store account I need to enable the 2 factor auth and this can only be done by logging in to a iOS or Mac OS device and enable the 2auth there. Every time I would login into my account from an unkown device I have to get the code from this phone with this companies account. 

Also when I will log-out of my private account all data will be lost. That is what a warning message says.


I cannot have my private and business Apple ID on one phone
I do not want to only have the business Apple ID on the phone because it is my phone not the companies
My company does not have the resources to buy another Apple device
The device we will use needs to stay in our hands


Above statements are the fact but not really my situation. What would one do to fix above scenario?
You cannot add the business account for 2FA to your iPhone without first logging off the private account. However, when you have logged into the business account and enabled 2FA, you can logout and then login to your private account again.

Instead of purchasing a new phone for the business, you can also use any other modern iOS or macOS device for enabling 2FA. I.e. you can use for example a Mac computer or an iPad or iPod Touch.