OpenSalesTax vs VAT Engine

OpenSalesTax is a free, self-hosted API that calculates sales tax for US transactions using public data and per-state modules. The project says its modules cover 52 jurisdictions, while each published data dump includes all 48 jurisdictions that impose sales tax. The API calculates tax on line items and can break results down by state, county, city, or district. Documented item categories include general goods, clothing, groceries, prescription drugs, prepared food, and digital goods. Its data comes from Streamlined Sales Tax files and state Department of Revenue publications, rather than paid tax feeds. The engine can be installed from source or run with Docker; PostgreSQL is the default, with optional MariaDB support. Access defaults to open with per-IP rate limiting, or can use API keys with per-key limits and usage tracking. Release dumps reflect the SST quarterly file current at release, and the project documents loading newer data. It identifies incomplete sub-state tax stacking for Colorado home-rule cities and Louisiana parish-level collectors. The project says its calculations are not legal or tax advice and advises checking results with the relevant state Department of Revenue before remitting.

VAT Engine is an EU VAT API for calculation and compliance workflows, aimed at ecommerce and finance teams. It runs on the web and through an API, and covers all 27 EU member states with 37 merchant-facing tax classes mapped from 88 official categories. It imports VAT-rate and SME-threshold data from the European Commission’s Taxes in Europe Database. Calculations can use a transaction date to select a reviewed rate version when one is available; periods without coverage are marked unverifiable.

Results can become transaction records. Source profiles, OSS thresholds, quarter previews, and accountant exports use the same model for review. The dashboard provides API-key generation, rotation, revocation, scoped permissions, usage tracking, two-factor authentication, backup codes, and activity logs. Shopify processing is described for an authorized connected store; platform-specific connectors for Shopify, WooCommerce, Magento, and Sylius are planned. Alpha access is free, with no payment method required. Availability, limits, support, pricing, and features may change during alpha. VAT Engine does not submit returns or provide legal or tax advice.