The avalara plugin is for a dynamic tax calculation for whole USA. The configuration is mainly done with a calculation rule.

Installation

  1. Go to your plugin manager in joomla, select type (drop-down) vmcalculation and enable "VM - Calculation Avalara Tax"
  2. Open your virtuemart administration, =>Taxes & Calculation Rules and create a new tax rule
  3. Choose for "type of arithmetic operation" "tax per bill"
  4. Set for the math operation "avalara"
  5. Value = 0
  6. Currency = USD
  7. Check "AvaTax activated" and fill in all the other information asked by AvaTax (Company Code, Account Number, License Key)
  8. Select the countries you want to use with Avatax
  9. Use for your products in the tax setup the default "Apply default rules"
  10. Use in the shipment "Apply no rule"
  11. As long you use the free demo, check "Enable the developer server"

Enable special shopperfields for tax usage

If you want to use the exemption number and set the tax usage type, go to your shopperfields and enable them. Important, do this using the edit view and store them, dont use just the publish button in the list. In case you updgraded from an version older than vm2.0.16, you must create them yourself. Important is that you name them tax_exemption_number and tax_usage_type, otherwise the plugin wont find the entered data.

In case you have too many requests to avatax, use the option "only in the cart". Then the request is only done in the cart.

AvaTax only for certain countries/states

In case you want that Avatax is only working for a certain country, but validating the address of the shopper, use the country selection in the AvaTax config area (at the bottom). If you need to restrict AvaTax for certain states, then use the country/state selection of the rule itself, but then there is no address validation for users outside selected state.

Item Code and Tax Code

Special product taxability rules can be defined using Item and/or TaxCodes;

ItemCodes represent individual products (and are often product SKUs), whereas TaxCodes represent categories of products. For example:
ItemCodes of M001 for Milk, E530 for Eggs, and C233 for Cheese.

A TaxCode describes a group of products with the same taxability. In our example, TaxCode of GR might be established for the broader category of Groceries.

Product Taxability Rules are defined in the Avalara Admin Console in terms of TaxCodes. For example, groceries are not taxable in the State of Washington, so a taxability rule might be established that states “when a line item is passed with the Tax Code GR, and the destination address is Washington, the line item is charged $0 tax.

You can very easily setup this tax codes in virtuemart creating unpublished categories with the prefix for the slug "avatax-". When a product is in a category which has the slug avalara-D00000, then this product is sent with the code D00000.

You will find more information, here http://www.avalara.com/