We currently support tax exemption codes, which are applied to a specific user, by an admin.
This code will make it so all transactions they make are tax free. This is not ideal, and some clients have requested we allow tax exemption to be on a per lot, and per permit basis.
I think this is much more useful than a tax exemption code because you wouldn't need to exclusively give a user the right to not pay tax. That could easily be used out of context if the user is only entitled to a tax free permit, but only in a certain lot (for example, parking related to work is usually tax exempt)