I can guide you on how to pay the sales tax in QuickBooks Desktop for Mac.
To make sure I'm on the same page, are you trying to set up QuickBooks for Mac wherein it will automatically calculate the sales tax amount without adding it to the customer's invoice or sales receipt? If so, QuickBooks automatically calculates the tax by using the tax item you choose for the customer. If you want, you can calculate the tax at a different rate by choosing a different tax item directly from the sales form.
QuickBooks won't be able to track the sales tax without adding it to the sales form.
Also, here are the three ways to find out how much tax liability you are accruing:
Sales tax liability report—See a summary of how much you have billed (or collected) on behalf of each sales tax agency.
To display, choose Reports. Under Vendors & Payables, select Sales Tax Liability.
Sales Tax Payable register—Scan the tax-related transactions QuickBooks has recorded in your Sales Tax Payable register.
Pay Sales Tax window—See how much you owe each tax agency. Pay the sales tax your business owes.
To pay the sales tax, follow these steps:
From the Vendors menu, then select Pay Sales Tax.
Choose the checking account you want to use for the tax payments on the Pay From Account drop-down.
In the Show sales tax due through field, make sure the date is correct.