Question about Character Alteration Voucher

[Ryro]

If I click to alter a charter's appearance, does that use the voucher as soon as I press the button or only after I press the "create character" button?

 

I want to make another appearance for my character, but I have 7 characters already and the game wont let me go into the character customization screen unless I delete one. I'd like to "create" the character first and then save the appearance, that way I can just select it when I'm ready.