Need to update the phone number on your Battle.net Account?
What to do when you receive the error "The phone number is invalid" when adding a phone number to your Battle.net account
Information about why you might get the message "An error has occurred." when you try to add a payment method
Troubleshooting steps for communication and transmission errors.
How to resolve this error when trying to log in to Battle.net
Information about this error when adding a phone number or a Battle.net Authenticator to a Battle.net account.
What to do if the website returns "Connection Error" when adding a phone number
How to create an account to play on the Public Test Realms
Information on Phone Number Not Eligible for Callback error
Before you can connect to the game servers, you must add a phone number to this account.