Hi Nanako, 

Thanks for reaching out. You've likely already found an answer, just wanted to chime in that Credit notes are used to record a reduction on an invoice or bill as a result of a customer/ vendor return or cancelled order. They resemble invoices, but have negative values. If you want to issue a credit note for future purchases as opposed to refunding the customer's money, you can cancel the original invoice and return the goods to inventory. Then you can enter a deposit for the customer for the amount of the original invoice.

If you are returning paid goods or services to a vendor, then you should either: 

• Void  the purchase invoice, and Sage 50 Accounting will automatically issue a credit noteon behalf of the vendor. OR
• Create a purchase credit note (Sage 50 Premium Accounting).
  
  

Hope this helps you or someone else!

Warm Regards, 
Erzsi