Credit notes are used to reduce the amounts owed to suppliers from previous invoices.
For example, if you have received an invoice for goods you have purchased but the goods have not been delivered, your supplier will issue a credit note to reduce the value of the original invoice (or clear it completely depending on the circumstances).
How to enter credit notes issued to you from suppliers
Supplier credit notes are entered in the same way as supplier invoices. Go to Suppliers > Supplier Credit Notes and click New Credit Note.
You can also create a new supplier credit note by selecting New Supplier Credit Notes from the Quick Links menu.
Select the supplier who issued the credit note. You will then be able to click on 'Invoices', to see a list of invoices which relate to this supplier.
Select the invoice (or invoices) which the credit note relates to.
Once this has been saved, you will notice that the amount you owe to your supplier will reduce by the credit note amount.