Deductions & credits

Depends ... if you report the total GROSS sales ( including the sales taxes collected)  then payment of those taxes you collected and paid  to the proper authorities would be an expense.   If you did NOT set up  your bookkeeping on the gross income method then you would ONLY report the net sales (less of sales taxes) then you cannot deduct the sales taxes ... it is one way or the other as long as you are consistent in your method.