Some states require businesses to charge tax on the shipping costs of an order. This can be easily set up when creating an order or booking proposal. Under the order/proposal settings, click on the "Configure Taxes" link and check the "Apply Tax on Shipping Cost" box. Your tax rate(s) will now apply to the shipping charges and factor into your taxable income in the reports under the Business section. You can save this as a default for all of your future shoots by clicking the "Save As Default" checkbox.
Note: You can only apply tax on shipping when choosing Tax By Percentage Rate; it is not an option when choosing Tax By A Fixed Dollar Amount.
When applying multiple tax rates to an order, all of the rates will apply to the shipping costs when the "Apply Tax To Shipping Costs" option is checked.