You can change the Sales / VAT taxes you need to collect under settings > edit company profile
FROM THE WEB APP
Step 1: Go to settings > edit company profile
Step 2: Add/Edit your relevant sales taxes
Step 3: (Optional) Set your default sales tax
Step 4: Save (at the bottom of the page)
FROM THE MOBILE APP
This setting can only be changed on the web app at this time. We are working to bring this functionality to the mobile app.