Summary: This article explains how The Shed App uses TaxJar to figure tax. This is a process that happens behind the scenes. At times this can be confusing if you are not aware of what is happening. The Shed App uses TaxJar to figure the tax for each order. This happens automatically without any extra input.
How to
Use Tax Rate Lookups with TaxJar
The tax rate is calculated in the Summary (step 3) of the order-form

After entering the customer’s billing address (optionally you may specify a different shipping address) and clicking Receive Payment, The Shed App will ask TaxJar what the tax rate should be based on the sales location and the location the shed is being delivered to.

In this example the tax is set to 8% automatically.
The Shed App is relying on TaxJar for tax-rates. You can view the TaxJar guarantee here – TaxJar Guarantee
TaxJar also provides a tax-rate calculator here Sales Tax Calculator – TaxJar