A finalized invoice in Provet is locked, because changing a past financial record is considered bad accounting practice. To correct the invoice, create a credit note. The credit note corrects the invoice and keeps the original invoice on record. For the different credit note options, see Overview of Credit Notes.

Credit and Refund an Item or a Part of an Invoice
​Credit and Refund a Finalised and Paid Invoice in Full
​Credit a Finalised Invoice That Has Not Been Paid