US SaaS taxability

The default ProductTaxability binding is RegisterTaxability. It reads the installed register and maps TaxClass::DigitalService into the register's category vocabulary. SaaS, prewritten software, custom software, hosting and data processing have separate classes; choose the one that describes the supply.

How a determination is made

For the supply's jurisdiction, amount and date, the source checks:

A published price exemption, including what happens above its threshold.
The nearest category with a published rate or exemption. A category is exempt only when every applicable record at that level is zero-rated or exempt.
Taxable when the jurisdiction has rate records but no category determination.

An incomplete price exemption refuses with UnresolvedProductTaxability. A jurisdiction with no rate records also refuses. The US regime applies the result after its registration and marketplace checks.

Behaviour changed with the register migration

The retired dataset carried an explicit undetermined verdict for some state/category pairs, which made the engine refuse. The register has no equivalent per-category marker. Those pairs now follow the taxable fallback above.

This can change the tax charged. Review the states and product classes you sell into when upgrading; the old static SaaS table is no longer a fallback. Bind your own Contracts\ProductTaxability when you need a more specific determination.

Taxability and rate precision

A taxable determination does not establish an address-level rate. The register source also needs the applicable local authorities. Where resolution stops at the state share, the rate carries Confidence::Derived and RateLimit::NoLocalResolution if local tax may be missing.

See register coverage and geocoding for the available resolution paths. Keep the assessment's rate provenance and limitations with the invoice so the data release and unresolved questions remain visible.