Be able to adjust invoice after finalizing

It still happens quite often that an invoice is finalized, is emailed to the client and the client indicates that something (textual) should be added to the invoice line, such as a location. The invoice finalization cannot be undone because the invoice has already been forwarded as an expense entry to the accounting system. Then we get a call asking if we can adjust it.

We have a number of options:

• Sell no: Indicate to the customer that the invoice should then be credited or remain as is.

• Allow invoice final undo and not redirect to accounting (Then we should allow invoice final undo in my opinion everywhere also by the backend employee).

• When opening a finalized invoice, make certain fields not editable (customer, rates, administration, invoice template)