US Sales Tax Automation calculates accurate state and local sales tax on every order by calling Avalara AvaTax or TaxJar at quote, order, and invoice time, instead of maintaining thousands of tax rates by hand. For US-based merchants and international sellers with US nexus — especially multichannel sellers using ECOSIRE marketplace connectors who face marketplace-facilitator versus direct-sale tax complexity. Planned features include real-time rate calculation with address validation, economic nexus threshold monitoring by state, exemption certificate handling, marketplace-facilitator awareness for connector-sourced orders, committed transaction sync for filing, and liability summaries by jurisdiction. This app is currently in development on the ECOSIRE build pipeline. It will ship first for Odoo 17, 18, and 19 simultaneously, with an ERPNext port following on the v15/v16 track — the same triple-version coverage as every live ECOSIRE app. One-time license, free updates within your major version. Register your interest on this page to be notified at launch and to help shape the first release.