While you can create taxes on the device, it's just as easy to create and assign them on the device. Look for the Taxes link in the Catalog section of Poynt HQ (https://poynt.net/catalogs)
From here, you can create new taxes or edit existing ones.
NOTE: You cannot delete a tax if it is currently assigned to a catalog. You have to unassign it from the catalog before deleting.
To apply a tax to your catalog, go back to the main page of Catalogs and click on catalog you would like to add the tax. Click on the Tax link just above the product squares.
Click on Add Tax when prompted. In the box that appears, choose Create Tax or Existing. In this case, since we've already created the tax, we'll choose from the existing list.
Once you click on Add, this will associate the tax with this particular catalog. This tax will be applied to all products in this catalog going forward.