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How does Address Validation Work within the AvaTax Service?


You want to know how address validation works within the Avalara AvaTax service.


Avalara AvaTax


  • We use the address provided by your system and compare it with our database, which is built on USPS and Canada Post registered addresses.

    • There is no validation available for countries outside of Canada and the United States

  • Errors typically occur because an address does not include enough information to validate as only one address, or the address is not yet registered, for example:

    • If a new address (new construction within the past 6 months) has not been updated in this data base, the AvaTax engine will not be able to return a normalized address  (below) because it simply does not exist.

      • To ensure the address is added to our database as soon as possible, send it to, include:
        • Full street address (House number, street, City, State/Province, Zip/Postal code)
        • Image of location from online map (Google, Bing, MapQuest, etc.) showing the physical location pinpoint
    • If an address is too close to multiple addresses, none match the address provided exactly, so we provide an error requesting more information, for example "123 ABC Street East", New York City, SC, 12345

      • Zip Code 12345 is in a different city (Schenectady not New York City)

      • Zip Code 12345 is not in a different state (NY not SC)

      • It includes a zip code, city, and state that do not match each other, so we cannot validate the address
  • Normalization returns Capitalization and Directional suffix exactly as in the USPS database, like below:

    • "900 winslow way, bainbridge island, 98110" will return "900 Winslow Way E, Bainbridge Island, WA, 98110-2450"

  • It is important to understand that there are two different types of address validations that can be performed:

    • Explicit - which are performed as a stand-alone address validation calls (Validate method)

      • Explicit address validations are standalone address validation calls (meaning address validation only – no tax calculations) that are passed to the AvaTax web service, then during the same call (or port opening)  results are returned with either a success -- if no ambiguous address information was passed -- a normalized address.

      • Otherwise an error message (i.e. AddressRangeError [see below]) indicating the problem and summary details related to the address submitted.

    •  Implicit - which occur during a tax calculation (GetTax method)

      • Implicit address validations, on the other hand, are a little more subtle and are tightly coupled to our GetTax method’s logic.

      • For example, when you make a GetTax call to our web service, the tax calculation engine attempts to resolve the address with the best possible address data that can be gleaned from the address data that was provided. 

      • The logic follows the flow chart below:


  • A typical validate address error results message would look like this:

    • Name: AddressRangeError

    • Severity: Error

    • Summary: The address number is out of range

    • Details: The address was found but the street number in the input address was not between the low and high range of the post office database.

    • Source: Avalara.AvaTax.Service.Address

    • Refers To: Address.Line1

    • See ErrorMessages.xls

  • Logically, to trap whether an address passed is good enough for the document in question, one only needs to collect the results on the zip code.

    • Was it Zip Code plus "55428-1234" or just a 5 digit Zip Code "55428" should help you decide if a follow up is necessary.

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