Depending on how you show the handling charge on your document, it may be included with your freight/shipping line item, or it can be a line itself in the GetTax request. In the case where your handling charge is combined with freight/shipping, you do not need a separate line on the GetTax request. There is a tax code that covers this scenario. When your handling charge is separately stated from the freight/shipping charge, you just need to treat the handling charge as another line. Here is another example: