Glossary

Every term used across TaxLens, defined plainly and in alphabetical order. Where a concept has its own page, it's linked.

A – C

Additive stacking: The principle that each jurisdiction in a location's chain levies its taxes independently and the amounts add together — there is no single combined rate. See Additive stacking.
BIS (PEPPOL BIS 3.0): Business Interoperability Specification — the PEPPOL profile that constrains EN 16931 into an interoperable, sendable e-invoice. TaxLens serializes UBL conforming to PEPPOL BIS 3.0.
Cap: A rule effect that limits a tax — either a maximum amount or a maximum number of taxable nights. The most restrictive cap wins when several compose.
Credit note (381): A fiscal document (document type 381) that reverses or corrects a previously issued invoice. It carries its own number, references the original, and marks it as credited. See The invoice lifecycle.
Commission tax: VAT on the OTA / intermediary commission line — distinct from the room VAT. It's where EU cross-border reverse charge applies. See Reverse charge.

Document type (380 / 381 / 389): UNCL1001 codes for the kind of fiscal document: 380 a commercial invoice, 381 a credit note, 389 a self-billed invoice (issued in the supplier's name). See Self-billing.
Effective rate: The total tax divided by the room subtotal (nightly rate × nights), expressed as a single percentage — a summary of how much tax the stacked components add up to. It is derived for display, not stored as a rate.
EN 16931: The European standard semantic data model for an electronic invoice. TaxLens projects a booking into EN 16931 Business Terms before serializing to UBL.
Exemption: A rule effect that makes a tax not apply for a given booking (long-stay, diplomatic, B2B reverse charge). The engine shows the tax was waived rather than silently dropping it.
GST: Goods and Services Tax — the consumption tax used in place of "VAT" in several countries (Australia, Canada, India, and others). Modeled the same way as VAT.

Idempotency key: A caller-supplied key that makes booking creation safe to retry: the same key returns the original booking instead of creating a duplicate. Reusing a key with a different body is a conflict. See Errors & idempotency.
Jurisdiction: Any place that levies a tax — country, state/province, county, city, or special district. Jurisdictions nest into a tree with hierarchical codes (US-NY-NYC). See Jurisdictions.
Legal issuer: The legal entity that issues an invoice — the seller of record on the document, with its name, address, and tax registrations. A property can default to one. See Legal issuers.
Merchant of record (MoR): The party that is the seller of record for the transaction — the property, the platform, or neither. It drives the booking's channel and how tax collection is routed. See Channels & merchant of record.

Occupancy tax: A lodging tax levied as a percentage or a flat amount per room-night (US hotel occupancy tax, Canadian MAT). Not recoverable VAT, so it's excluded from the VAT-only e-invoice.
Override: A rule effect that replaces a rate's value — for example an override to 0% carrying a reverse-charge reason, which keeps the taxable base while charging no VAT.
PEPPOL: The Pan-European Public Procurement OnLine network and its document specifications. TaxLens generates PEPPOL-conformant UBL; it does not transmit over the network (no Access Point).
Rate: A single tax attached to one jurisdiction — its category, value, basis, and active window. Every layer of a stacked total is its own rate row.
Reduction: A rule effect that applies a percentage discount to a tax. Reductions stack multiplicatively when several apply.
Reverse charge: A VAT mechanism that shifts the liability from supplier to a business customer. In accommodation it applies to the OTA commission line, never the room (taxed locally as a service connected to immovable property). Tagged EN 16931 category AE. See Reverse charge.
Rule: Logic that sits on top of a rate and adjusts the outcome for a specific booking — an exemption, override, cap, surcharge, or reduction. See Rules.

Self-billing (389): An invoice the platform / merchant-of-record issues in the supplier's name, on its own fiscal counter (document type 389). See Self-billing.
Surcharge: A rule effect that adds an additional percentage applied to the taxable base (stacking additively). Surcharges stack additively.
Tax category: The classification of a tax (VAT, occupancy, tourism, eco…) that determines how its amount is computed. See Tax categories reference.
Tax registration: A legal issuer's registration with a tax authority (a VAT number and its scheme), which scopes how invoices are issued in that jurisdiction.
Test / live mode: Test mode exercises the full flow without producing live fiscal data; live mode produces real invoices and real fiscal numbering. See Test vs live.
Tourist / city tax: A lodging levy, usually per guest per night (European taxe de séjour, imposta di soggiorno). Like occupancy tax, it is not recoverable VAT.
UBL: Universal Business Language — the XML format TaxLens serializes an EN 16931 invoice into (UBL 2.1, PEPPOL BIS 3.0). See Standards.
VAT: Value-Added Tax — the recoverable, invoice-grade consumption tax charged on the room (and, on multi-rate invoices, on certain fees). The tax that appears on the e-invoice.
VAT base: The amount VAT is charged on. Usually the room alone, but where the tourist/occupancy tax is operator-levied it can be the room plus that tax. See VAT base.