This extension is deprecated and won't be maintained anymore.
Please migrate to Spree Avatax Official which is a faster, more stable extension which uses Avatax API v2. It's Avatax certified.
gem 'spree_avatax_certified', github: 'spree-contrib/spree_avatax_certified', branch: 'master'
bundle exec rails g spree_avatax_certified:install
Configure specific users to utilize Avalara Entity Use Code, and Exemption number; Customer Code will be the user's id. Exemption Number are sourced from the Avalara site and the Avalara Entity Use code is a searchable drop down that was previously configured in the system.
Be sure to bundle your dependencies and then create a dummy test app for the specs to run against.
$ bundle exec rake test_app
$ bundle exec rspec spec
Copyright (c) 2016 Boomer Digital, released under the New BSD License