When do I update the price in a supplier return invoice?

If the return invoice is created automatically, it will by default use the price from Purchase Order (PO).

In cases where the fiscal document price is different from the PO price, you must ensure that the invoice is updated to the fiscal document price so that the accruals and supplier liability are properly reversed.

In a scenario where the debit memo was created and processed with a price different from the fiscal document price, you have to manually adjust the difference by running the Accrual Reconciliation job in receipt accounting, and performing the cost adjustment in cost accounting.