Country coverage

The engine's principle is own the calculation logic, source only the rate data — and omit a country rather than ship a rate we cannot stand behind. This section documents exactly what is supported, with the authoritative source and a confidence level per jurisdiction, and lists the jurisdictions we deliberately do not yet cover with the reason.

• Supported jurisdictions — regime, rate, source, confidence.
• Not yet supported — researched but omitted, and why.
• EU VAT rate feed — the real, MIT-licensed EU VAT dataset the engine can bind, its source and license.
• US tax dataset — the compiled us-tax-data source behind US rates, taxability, nexus and sourcing (on by default).
• US SaaS taxability — the curated, cited per-state SaaS map (the fallback when the dataset is disabled).
• US economic-nexus thresholds — the cited per-state Wayfair threshold table (the fallback when the dataset is disabled).

Two boundaries to keep in mind:

• Rate data vs regime coverage. "Supported" means the engine models the jurisdiction's logic (place of supply, reverse charge, rate application). The rate number is data supplied by a TaxRateSource; the shipped default rates are a starting point, and production should bind an authoritative feed.
• Tax rate ≠ e-invoicing. This engine calculates tax. It does not handle mandatory e-invoicing / clearance mandates (Brazil NF-e, India IRN, Italy SdI, Mexico CFDI, Poland KSeF, Saudi ZATCA, …) — that is a separate invoicing concern.