In ERPAG, you can issue a write-off on every invoice.
If you want to reduct the total amount of an invoice or your invoice is partially paid and you do not expect to receive the rest of the payment and you want to write it off, or you just want to write-off the petty cash, go to:
Sales > Sales orders
Select the wanted invoice from the list and open it. Click on the payment button from teh right-hand side of your screen.
Now, select the write-off from the drop-down menu and record the payment.
The status of the invoice will be changed to 'paid'.
In case you receive a write-off from your supplier, you can register it by opening the specific suppliers invoice or the purchase order and going through the same steps as in sales. Click on the payment button, select 'write-off' from the drop-down menu and record the payment. The status of the document will change to 'paid'.