How can my kids use existing iTunes money with Music?

[iMore Question]

Apple Music automatically wants to charge my card for a new purchase...I need to know how to my kids can use the money they have already credited to their accounts from gift cards.

 

[kch50428]

Unless something has changed... balances on individual AppleIDs should be used before trying any other payment source.

 

[iOS Gravity]

It shouldn't be asking you that unless the amount of iTunes credit left is not enough to pay for the first month of paid Apple Music service.