Thanks for getting in touch with the Community, snsmile. I appreciate your detailed information.

When an invoice is created in QuickBooks, the amount on hand for each inventory product included on your invoice is decreased by the amount you specified on your sales form.

What you're seeing is the accurate count for your quantity on hand amount. The product is taken out of your inventory when the invoice is created.

You can learn more about tracking inventory in our Set up & track your inventory article.

Please don't hesitate to send a reply if there's any additional questions. Have a great Tuesday!