Why not try this:

Make one customer Name for “Evaluation” and use that for SO for Sent items. Now, when you see what is on Open SO for that name, these are Out and not available. When you are done with that line item or SO, Close it.

Resolution for 'about keeping issue: 'What is the best way to go about keeping track of product that we send out as samples that may or may not be sold?' available: Yes.

The about keeping 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 about keeping issue yourself by looking for a resolution described in the article. If it is a complex about keeping issue or you are unable to solve the issue, you may contact us by clicking here or by using other about keeping support options.

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