Standard when you enter supplier invoices there is no check if you already entered an invoice or not. This is usefull if invoices are manual and not created via purchasing, but also here if you by mistake enter an invoice again manual Odoo does not check if was entered before. Also in this module a new feature is available that warns you when you create a partner with an existing VAT number linked.

Also a complete feature regarding supplier invoice hold in this module will be released soon. Standard Odoo does not provide the functionaly to put an invoice on hold and block for payment, either coming from a manual hold, credit check hold or invoice price variance holds based on a % variance you can define. This module will add these features and also changed basic workflow.

Features:

*A feature has been added that checks for duplicates entries on supplier invoices, the  moment you want to enter a supplier with a reference (their sales invoice number) that already has been used a message warning will pop up.
*Invoice due date is calculated when invoice date is filled in and displayed on the invoice.
*New feature will be added soon, wich will display the credit note as a negative number in the invoices overview.