Avalara AvaTax is an advanced solution that uses geolocation and address verification to calculate sales tax down to a specific address, accounting for multiple tax jurisdictions in a single ZIP code, complex tax tiers, and more. If you need to calculate tax on international transactions, AvaTax offers an option for that too. Avalara also has solutions to prepare and file your returns, as well as easily manage exemption certificates in the cloud, all of which integrate seamlessly with AvaTax.