InvalidCountryRegion
Example
{
	"code": "InvalidCountryRegion",
	"target": "Unknown",
	"details": [
		{
			"code": "InvalidCountryRegion",
			"number": 126,
			"message": "Invalid country and region combination.",
			"description": "The region '-1-' is not a recognized region within country '-0-'.",
			"faultCode": "Client",
			"helpLink": "http://developer.avalara.com/avatax/errors/InvalidCountryRegion",
			"severity": "Error"
		}
	]
}
Explanation

This indicates that you specified a country/region that was not recognized by the ISO 3166 country/region code system. Avalara recognizes all ISO 3166 country codes and some regions within these countries. Please verify that the country/region combination you are specifying matches the ISO 3166 definitions.

For more information on the international standard for ISO 3166 country/region codes, please see the ISO webpage: http://www.iso.org/iso/country_codes or the Wikipedia article listing current codes: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2