Payment References for Sale Refunds

In Finnish business accounting, refunds to customers are often not paid out as cash. Instead, they are used to reduce the amount owed on later invoices. To make those refunds easy to follow and match, they need a payment reference just like a normal sales invoice.

By default, Odoo only creates payment references for sales invoices. This module changes that behaviour on the account.move model so that a payment reference is also filled in for customer refunds.

• The reference is generated automatically when a refund is posted.
• It is only added if the refund does not already have a payment reference, so nothing is overwritten.
• It applies to customer refunds (out_refund), not to vendor bills or other document types.
• The reference uses the same standard reference calculation that Odoo already uses for invoices.

There are no new menus, screens, buttons or reports. The change happens quietly in the background when a refund is posted, and the reference appears in the usual payment reference field on the refund. This module touches the accounting area only and depends on the standard Accounting app.