QuickBooks Error message: "You cannot use the same tax item in both the line items and the txn tax"
Occurs: When importing a sales transaction into QuickBooks desktop and you have mapped both a Tax Item at the Item Ref Full Name field and also to the Item Sales Tax Code. QuickBooks will not permit you have a Tax Code at the line level and at the footer level.
Resolution: You will need to map either the Tax Code to the Item Sales Tax Code field
on how to map Tax Codes on sales transactions