SaaS Pro - REST API User Guide Last updated Save as PDF Learn how AvaTax for Communication APIs connect with REST interfaces.Handle duplicate or erroneous transactionsSet a transaction-level Safe Harbor Override in REST v1Most popularHandle duplicate or erroneous transactionsSet a transaction-level Safe Harbor Override in REST v1Shortcuts News Flash Release Notes - All Products See also Handle duplicate or erroneous transactions AvaTax for Communications SaaS Pro REST v2 developer guide