Let's say a client has signed for a project, but then calls you back to let you know that they're tax exempt. Here's how you can remove the taxes from that project.
You'll just need to 'Edit' the signed contact.
Then click 'Override Taxes' at the bottom of the project and mark the project either Tax Exempt or Resale.
Want to know why you're selecting if it's Tax Exempt or Resale? Find out more here (Article)!