Mandatory Split Payment

This function adds a warning before post of Sales Invoices if the "split payment lines" have not be added in the document.

"Split Payment" is an Italian regulation that allows to reverse VAT amounts in invoices for the Public Administration. Reverse is done adding negative "full VAT" lines in the invoice. These lines are added manually in the standard version.

This function is useful in batch posting process to avoid to forget "split payment lines".