[Resolvido] Transfer license

I have an unlimited and lifetime license that I use to develop multilingual websites for my clients. Now one of my clients wants to start using the automated translation, and needs to buy translation credits from you.
Does he need to change to his own WPML licence, or is it possible for him to keep using my license and pay the translations directly to you, with his credit card, only for his website?
I've clicked on "Switch to pay-as-you-go" on "Sites Using Prepaid Credits" > link oculto and got redirected to link oculto which is a blank page.