You can add 1 or 2 sales taxes to your quotes and invoices.  


You can assign or modify the sales tax percentages. 


Go to Setup -> System Values



Once there, go to Tax 1 or Tax 2 tab:


a) To delete a tax percentage from your list click on the trash can 


b) To modify a tax percentage click directly into the value 


c) To add a new tax value click on "+" symbol 


d) To set a default tax value mark it from the default column.



TIP: When selecting a default value, this will be added to all the quotes.