I'm opening this thread to ask for some help but I have no hope. The problem I'm trying to solve is so frustrating that even describing it is a frustrating experience. It's about Upgrades/Downgrades. Preamble For various reasons (tax regulations in force in several countries) I have to consider Add Funds invoices with tax. Normally when you want to add 100 € funds WHMCS issues a 100 € invoice. Customers pay their taxes when the credit is used to pay other invoices. As I said earli