Problem
Materials are automatically added to invoices when POs are received.
Solution
Stop materials from being automatically added to invoices from purchase orders
Note: If you only have the Purchasing module enabled, the Inventory section in the navigation bar and under Settings is renamed Purchasing.
Go to the navigation bar and click Settings.
From the side menu, select Purchasing or Inventory.
Select Configuration.
Click on the Purchasing or Inventory tab.
Uncheck the box next to Option to add inventory items to invoices.
Save your changes.