IT IS VERY NECESSARY FOR THE SYSTEM TO ALLOW NEGATIVE BILLING FOR SEVERAL REASONS:
  1. THE EMPLOYEE MAY BE MOTIVATED BY THE EASE OF THEFT, SEEING THAT THERE IS AN ERROR IN THE COMPANY'S INVENTORY AND THAT IN ADDITION THE SYSTEM DOES NOT ALLOW HIM TO INVOICE A PRODUCT SO THERE ARE NO STOCKS. MAKING IT EASIER FOR MONEY TO BE KEPT AND NOT INVOICED (NO ONE WILL NOTICE). BECAUSE IT CANNOT BE TRACED. (THE SOLUTION THEY PROVIDE FROM SUPPORT IS TO CARRY OUT A STOCK ADJUSTMENT, WHICH IS NOT FEASIBLE EVERY TIME THIS HAPPENS THE ADMINISTRATOR HAS TO SOLVE)
  2. AN ORDER WITH X PRODUCT ARRIVES AND THE SALE CANNOT BE MADE UNTIL THE INVOICE IS ENTERED. THIS HINDERS THE SALES PROCESS AND CUSTOMER COMPLIANCE, EVEN WHEN WE HAVE THE PRODUCT. IT WOULD BE EASIER FOR THE ALLY TO ALLOW THE SALE TO BE MADE IN THE NEGATIVE AND THEN THE QUANTITIES ARE ADDED BY ENTERING THE QUANTITIES THROUGH THE PURCHASE INVOICE.
I SEE THAT THERE ARE SEVERAL USERS ASKING FOR THE SAME SOLUTION. I HOPE THESE UPDATES CAN BE GIVEN SOON:D