Credit a sales invoice in Aedon.Accounting with the Credit button, which copies its lines into a sales credit, then allocate the credit to the invoice.
Creating a Sales Credit
Create a sales credit in Aedon.Accounting manually or from an invoice, then post it and allocate it to the customer's invoices.
Sales Credit
What a sales credit is in Aedon.Accounting: a credit note that reduces what a customer owes, how to allocate it to invoices, and its posting rules.