Regimes

A regime is selected by the regimeModule key on the buyer jurisdiction's tax profile (from laravel-geo).

Shipped

• EuVatRegime (eu-vat) — destination VAT at the customer's Member State rate; intra-EU B2B supplies to a validated customer reverse-charge. It also applies the Art. 59c €10,000 micro-business threshold (see below).
• NationalTaxRegime (uk-vat, ch-vat, no-vat, au-gst, nz-gst, mx-iva) — single national-rate VAT/GST with a cross-border B2B reverse charge.

Both share DestinationTaxRegime: a cross-border B2B supply to a tax-ID-validated customer reverse-charges; everything else is taxed at the place-of-supply rate (overridable per regime — the EU regime overrides it for origin sourcing).

Collection is gated on the seller's registrations

A regime decides the rate and the treatment. Whether this seller collects it is a separate question, asked after: outside the United States, a would-be Standard supply comes back NotRegistered when the seller is neither established nor registered in the place of supply. Inside the Union an OSS or IOSS registration covers every Member State, and an EU-established seller stays on the Union's rules.

This catches the common case of a shop selling abroad for the first time: the tax is due, but it is collected at the border from the buyer, not by a seller with no number to remit it under. See seller registrations.

EU €10,000 micro-business threshold (Art. 59c)

A seller established in a single Member State, below the €10,000 combined cross-border B2C threshold (current or preceding year) and not opted into OSS, charges its own (origin) VAT on cross-border B2C supplies to other Member States; once it opts in or crosses the threshold, the general destination rule applies. The seller supplies these signals on SellerRegistrations::$oss (OssStatus { registered, thresholdExceeded }). The two are not interchangeable: thresholdExceeded moves the place of supply, while only registered — or an oss / ioss scheme registration — is a number to collect with, which the gate above asks about separately. Deny-by-default: the engine never infers turnover, and absent an asserted status it applies destination. B2B reverse-charge is unaffected.

Reverse charge, and the supply that is not one

Reverse charge applies only when the supply is cross-border (the selling entity is not established in the buyer's country), the customer is a business, and their tax ID is validated (customerTaxIdValidated: true) — because zero-rating legally hinges on a valid customer VAT/registration number. Otherwise destination tax is charged.

Goods inside the EU are not a reverse charge. Art. 138 exempts the dispatch and the customer accounts for the acquisition in its own state: a different provision from the Art. 196 reverse charge on services, with a different invoice citation, a different box on the return and its own column on the EC Sales List. The engine reports it as TaxTreatment::IntraCommunitySupply, and TaxAssessment::isReverseCharge() answers true for both — the invoice-side question ("does the seller charge?") has the same answer, while isIntraCommunitySupply() tells them apart for a filing.

A supplier not established in the state. Selling to a business there, who accounts for the tax is the member state's own rule (Art. 194), and the states differ: Germany reverses work deliveries and services by foreign businesses but not plain deliveries of goods; France reverses goods where the customer is registered in France. The register publishes each state's rule with its conditions, read like a rate's. The engine states what the query establishes — goods or service, whether a service falls under the general rule for a business (Art. 44), whether the supplier is registered there, and whether the customer is: a validated customerTaxId whose prefix is the state's says yes; one from another state says nothing, since a business can hold several. The rest — a work delivery, a service connected with property — come from the caller's facts. Until they do, the answer is the one given before the rule was read (a reverse charge) and says so: TaxAssessment::$limitedBy is AttributionUnsettled, which needsReview() reads. Goods that stay in the state are a domestic supply, never an intra-Community one.

Exempt is not zero-rated. Both charge 0%, and they are opposite facts to a return: a zero-rated supply is taxable at nothing, so the seller keeps the right to deduct the input tax behind it; an exempt supply is outside tax, and the deduction goes with it. They are filed in different boxes. The register files the two as different kinds, the rate carries it as RateKind::Zero or RateKind::Exempt, and the treatment follows — in every regime, so a Canadian exempt medical service is Exempt and a zero-rated grocery ZeroRated. An exempt EU invoice carries the exempt mention. The register names no article per rate, and Art. 226(11) accepts "any other reference indicating that the supply is exempt", so the mention is the words alone; a host that knows the provision it relies on prints it beside them.

Sub-federal regimes

• UsSalesTaxRegime (us-sales-tax) — dataset-backed, state-precision. Destination sourcing with three gates: the state must be resolved (via an AddressGeocoder), the seller must have nexus in it (a registration), and the product must be taxable there (ProductTaxability). Otherwise it returns NotRegistered or Exempt — never a wrong charge; a jurisdiction with no resolved state raises JurisdictionNotResolved. Rates, per-state taxability, nexus thresholds and intrastate sourcing come from the register. Address-level precision depends on what the register publishes for the state — a street index, a ZIP+4 boundary file, a polygon layer or a county name — and absent a resolved locality the state share applies, flagged; see coverage.
• CaGstRegime (ca-gst) — Canada has no local sales tax, so a province (subdivision) determines the rate: the federal GST plus the province's PST or QST, or the harmonised HST in its place. A PST is collected only by a seller registered in that province — a SellerRegistration with the subdivision; one registered federally charges the federal share. A cross-border non-resident B2B supply to a registered customer is self-assessed (reverse charge).

A jurisdiction whose regimeModule is not registered at all still raises UnsupportedJurisdiction — never guessed.

Buyer exemptions

Independently of the regime, a query may carry a buyer exemption certificate. The calculator applies it after the regime's verdict, deny-by-default: a valid exemption covering the taxed jurisdiction rewrites a would-be Standard line to Exempt, and leaves reverse-charge, not-registered and zero-rated outcomes untouched. It works across every regime because it composes over the assessment, not inside each regime.