Ruby gem to calculate sales tax using



TaxCloud is a free service to calculate sales tax and generate tax reports. The tax_cloud gem allows you to easily integrate with TaxCloud's API.

Getting Started

Create a TaxCloud merchant account at Add a website to your account under Locations. This will generate an API ID and API Key that you will need to use the service.

TaxCloud also offers an optional address verification API. To use it, you need a USPS (United States Postal Service) Address API UserID. To obtain your USPS UserID:

  1. Download and Install the USPS Shipping Assistant from

  2. Launch the USPS Shipping Assistant and go through the Shipping Assistant registration process.

  3. Once you have registered for your Shipping Assistant account, you can find your USPS Shipping Assistant UserID in the “About” box, in parentheses to the right of the name of the registered user.


Add the gem to your Gemfile.

gem 'tax_cloud'

Configure your environment. For example, create an initializer in Rails in config/initializers/tax_cloud.rb.

TaxCloud.configure do |config|
  config.api_login_id = 'your_tax_cloud_api_login_id'
  config.api_key = 'your_tax_cloud_api_key'
  config.usps_username = 'your_usps_username' # optional
  config.open_timeout = 1 # optional
  config.read_timeout = 1 # optional

The open_timeout and read_timeout options are used to specify waiting time for the TaxCloud web service response in seconds. Default values: open_timeout = 2 and read_timeout = 2.

Using TaxCloud

Define the destination and origin addresses using TaxCloud::Address.

origin =
  :address1 => '162 East Avenue',
  :address2 => 'Third Floor',
  :city => 'Norwalk',
  :state => 'CT',
  :zip5 => '06851')
destination =
  :address1 => '3121 West Government Way',
  :address2 => 'Suite 2B',
  :city => 'Seattle',
  :state => 'WA',
  :zip5 => '98199')

Create your Transaction and set up your cart items

transaction =
  :customer_id => '1',
  :cart_id => '1',
  :origin => origin,
  :destination => destination)
transaction.cart_items <<
  :index => 0,
  :item_id => 'SKU-100',
  :tic => TaxCloud::TaxCodes::GENERAL,
  :price => 10.00,
  :quantity => 1)
lookup = transaction.lookup # this will return a TaxCloud::Responses::Lookup instance
lookup.tax_amount # total tax amount
lookup.cart_items.each do |cart_item|
  cart_item.tax_amount # tax for a single item

After you've authorized and captured the transaction via your merchant account, you should do the same with TaxCloud for maintaining accurate tax information.

transaction.order_id = 100
transaction.authorized_with_capture # returns "OK" or raises an error

Later, you may need to mark some cart items as returned. TaxCloud will ignore any cart items that you don't include.

transaction.order_id = 100
transaction.cart_items <<
  :index => 0,
  :item_id => 'SKU-100',
  :tic => TaxCloud::TaxCodes::GENERAL,
  :price => 10.00,
  :quantity => 1)
transaction.returned # returns "OK" or raises an error

Verifying Addresses

TaxCloud optionally integrates with the USPS Address API. An address can be verified, which can also yield a 9-digit zip code that helps determine a more accurate tax rate.

address ={
  :address1 => '888 6th Ave',
  :city => 'New York',
  :state => 'New York',
  :zip5 => '10001'

verified_address = address.verify
verified_address.zip5 # 10001
verified_address.zip4 # 3502 # 10001-3502

Tax Codes

TaxCloud maintains a list of all Taxability Information Codes or TICs, which can be found at

You can obtain all tax codes as well as lookup a tax code by ID.

TaxCloud::TaxCodes.all # a hash of all codes
tax_code = TaxCloud::TaxCodes[TaxCloud::TaxCodes::DIRECT_MAIL_RELATED]
tax_code.ticid # 11000 or TaxCloud::TaxCodes::DIRECT_MAIL_RELATED
tax_code.description # "Direct-mail related"

Tax codes are organized in groups.

TaxCloud::TaxCode::Groups.all # a hash of all groups
tax_code_group = TaxCloud::TaxCode::Groups[TaxCloud::TaxCode::Groups::SCHOOL_RELATED_PRODUCTS]
tax_code_group.group_id # 3 or TaxCloud::TaxCode::Groups::SCHOOL_RELATED_PRODUCTS
tax_code_group.description # School Related Products
tax_code_group.tax_codes # a hash of all codes in this group

Tax code constants are defined in tax_code_constants.rb and tax code group constants in tax_code_group_constants.rb. These files can be generated by running the following rake tasks.


Tax States

TaxCloud manages a list of states in which you can calculate sales tax. The default setup will only have SSUTA (Streamlined Sales and Use Tax Agreement) states enabled. All other states will return $0 for tax values. To enable other states, go to You can find more information about SSUTA here.

Running Tests

  • VCR and WebMock are used to replay requests and avoid hitting the API each time. To refresh the mocks, simply delete the test/cassettes directory.

  • Run tests.

    rake test
  • If you need to record new requests against TaxCloud, set your keys first.


    The mocks will filter out your configuration details.

Bugs, fixes, etc

  • Fork.

  • Write test(s).

  • Fix.

  • Commit.

  • Submit pull request.


Copyright Drew Tempelmeyer and contributors, 2011-2014.

This gem is licensed under the MIT license.