There are problems with lprincecpa's answer.  In many states and local jurisdictions, what is known as a sales tax is actually a transaction privilege tax levied on the seller . . . the seller is not just collecting an amount from the buyer and then remitting it to the government agency(ies).  In these cases, the liability belongs to the seller and the expense is a seller's expense.  If the amount is included in the selling price (the amount received), then, for tax purposes, it can also be deducted on the business return.

In these cases, the seller should be recording the tax expense on either the accrual (time of sale) or cash basis (time of payment).  QB can be configured for either case based on how the seller keeps its books.