because the cost in the product list is for reference it is not the cost that posts to COGS when you sell the item (assuming inventory is used correctly)

QBO keeps FIFO cost, first in first out, so cost of the item that sells is determined by the purchase date.  ie

1/2/xx […]

Resolution for 'assuming inventory issue: 'I entered a vendor bill with 3 items at a cost of $19.52 that currently had 0 quantity at a cost of $21.90 in the products list. The product list still shows $21.90.' available: Yes.

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

For more information about resolving issues related to assuming inventory in Quickbooks/QBO or to get support for the issue 'I entered a vendor bill with 3 items at a cost of $19.52 that currently had 0 quantity at a cost of $21.90 in the products list. The product list still shows $21.90.', click the link below: