The credentials you provided to AvaTax could not be validated.


  "code": "AuthenticationException",
  "target": "Unknown",
  "details": [
      "code": "AuthenticationException",
      "number": 30,
      "message": "Authentication failed.",
      "description": "Unable to authenticate the user or the account.",
      "faultCode": "Client",
      "helpLink": "",
      "severity": "Exception"


AvaTax provides multiple modes by which you can authenticate your API call. You may provide one of the following:

	Basic username:password
	Basic accountid:licensekey
	Bearer token

This error message indicates that the username and password you provided could not be found.

Common troubleshooting steps:

  • Have you forgotten to Base-64 encode your username+password?
  • Have you mistyped your username or password?
  • Are you attempting to authenticate against the sandbox server when you intended to use the production server, or vice versa?