Tax Exemption

Is there an option that a customer can select to be tax exempt when checking out so they can then fill in a exempt form which will be sent to the vendor and the tax will then be knocked off the checkout?

Hi,

You can use the VAT options in Display > Custom fields, enable the custom field "VAT number".
And in the tax rules, create two different one, one for customers with VAT and one for the other ones.

This way some customers can be tax exempted.
Hope this is what you are looking for.