Create a non inventory item called return-noitem, set the expense account on the item screen to a discount account (it should be a sales discount income account, but if you already have a discount expense account use that)

On the customer credit, use that item enter the amount as a positive

Resolution for 'back into inventory issue: 'How do I handle a customer return for a product that has been openned and can not go back into inventory?' available: Yes.

The back into inventory issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the back into inventory issue yourself by looking for a resolution described in the article. If it is a complex back into inventory issue or you are unable to solve the issue, you may contact us by clicking here or by using other back into inventory support options.

For more information about resolving issues related to back into inventory in Quickbooks/QBO or to get support for the issue 'How do I handle a customer return for a product that has been openned and can not go back into inventory?', click the link below: