Go to Sales, then click Sales Credit Notes, and select New Credit Note.
In the Customer field, select a customer from the list, or type the customer's name.
If this customer is not one of your saved contacts, create a record for them by selecting Add a customer. You only need their name and address for now, and you can fill the rest in later.
On the first credit note line, select a product or service from the list, or start typing its name to find it.
If this product or service is not one of your saved items and you want to create a record for it, create it now by selecting Create item.
If you don't want to create a record or use a saved item, just type in the details for the item you're crediting.
Repeat on a new line for as many items as you need to add to your credit note.
Optionally, add Notes and Terms and Conditions to your credit note. These show on the credit note you send to your customer.
Select Save.