The following structure is a hierarchy. Copilot looks from top to bottom for importance. (ex. if none of the above apply, then we look at the Default Tax Rate) 

Is Customer Tax Exempt?

If the selected customer is tax-exempt, taxes will always be 0.

Property Settings

You can add entries to the property's Items & Services section and set their tax values.

If you selected a property for your line item, we would check if you have a matching Items & Services entry for that property, and we'll use the tax value of the matching Items & Services entry.

Line Item Dropdown

If you choose a line item from the dropdown when creating a visit, invoice, or estimate, we will use the tax value used in the past for that line item.

Your Default Tax Rate

If none of the above apply, we will use your default tax rate (if it's set).
The default tax rate can be set on the Settings > Invoices & Estimates page.