Hello,
If it's just for record keeping, you could create an expense account called "sales tax paid" and when you get a bill from a vendor, just break up the gross amounts and the sales tax charged and add them as 2 line items on the bills.
Just keep in mind that since this is someone charging YOU sales tax, you don't have to record it separate and pay it. That is the responsibility of the business or person that is COLLECTING the sales tax.
