Taxability mapping
Some states tax SaaS as tangible equivalents; others exempt it—configure product codes carefully.
Sourcing & location
Confirm origin vs. destination sourcing and how address validation impacts rates.
Billing & invoices
Show tax lines clearly; prorate correctly for mid‑cycle changes.
Exempt customers
Collect exemption certificates and automate expiry checks.
Operational controls
Run monthly completeness tests between invoicing, tax engine, and GL.