If you need to track sales tax on purchases (expenses, accounts payable), this must be tracked manually. QuickBooks is not setup to track sales tax automatically on non-sales transactions (such as bills, checks, purchase orders).
Tracking sales tax on purchases as an expense (not to be paid later)
Tracking sales tax on purchases as a liability (to be paid later)
If this solution does not resolve the issue, you can read discussions and post messages and questions relating to your issue on the Intuit QuickBooks Community site for free or you can contact a technical support agent for additional guidance. Fees may apply.