Switching Apple IDs and maintaining app functionality

The purchased and subscribed contents of Apple Accounts cannot be relocated, and cannot be merged.

You’ll have to re-buy the apps and subscriptions you still want.

You can relocate your own content.

Usual means of avoiding this is setting up Family Sharing, and sharing both accounts.

Depending on why you are doing this, details of an Apple Account such as names and email address can be changed, as well.

demaris274 wrote:

Every time I download a free app from the Apple Store is giving me a billing payment

Apple requires valid payment information be on file for many people.

If an Apple Account has money owed to Apple, they will expect payment before allowing various operations, or they’ll expect you to discuss this directly with them and to explain why you don’t owe them money.

Every time I download a free app from the Apple Store is giving me a billing payment

I do not know how to switch that