Hi Tom,

Currently the only features that SmithCart supports in regards to Tax exemption, is by role and by product. One option would be to configure the Tax exempt by role feature. Then you could create a new role called something like "Tax Exempt Customers" and add the Tax Exempt customer to the role manually in DNN.

Another option would be to create a coupon for the amount of the tax and add it to the order after it has been submitted.

In addition, If you would like a feature to be enhanced to support the exact functionality you are seeking our programming department is available to make the customization. If you are interested please submit a quote at the following link:

http://www.smith-consulting.com/servi...

Hope this helps! Please let me know if you have anymore questions. Thanks!