An option under payment method that allows you not

An option under payment method that allows you not to charge State sales tax, especially for non-profits companies.

In the state of Texas, when nonprofit companies purchase items, they do not have to pay sales tax. It would be nice to see an option in eTapestry that will not allow sales tax when the account type shows "Foundation", which is what we use for nonprofit companies in the database. Would it be possible to linked the account type to an option that will not add sales tax to purchased items?