Users can set up default prices and taxes in the Product Catalog. Navigate to the My Company section of the Sitemap -> Catalog -> View Catalog.
From this page, you can edit the default tax value for any given Product/Service. Simply go to the Product/Service and edit the appropriate field (‘Tax%’ or ‘Price$’) as/if needed. Note: if the Customer has already been assigned a tax rate (through the My Company section of the Sitemap -> Company Profile -> Settings) it will override the default tax rate in the Catalog.
Alternatively, users can access the Catalog from the drop-down menu on the top right of the screen.