Normally, you would make a Credit note from an invoice whose status is open.

What happens when you want to make a credit note from an invoice whose status is closed i.e. the invoice has been paid?

Sap Business One offers a solution for this.

When you right click an A/R Invoice, there an option called ‘Change Document Status to Open‘.

This option will help you change the status of the invoice to open, therefore allowing you to create a credit note that is based on that invoice you have reopened the status.