E-Invoice Glossary
The complete reference for European e-invoicing terminology. From EN16931 business terms to country-specific identifiers.
Popular Terms
BT-1 Invoice Number
BT-1 is the unique sequential identifier assigned to an invoice by the seller, required in every EN 16931 e-invoice.
BT-10 Buyer Reference
BT-10 is a text field in the EN 16931 semantic model where the buyer's reference identifier — such as a purchase order number, project code, or routing ID — is carried on the invoice. Optional in EN 16931, but mandatory in key CIUS profiles like XRechnung and Peppol BIS 3.0.
BT-24 Specification Identifier
BT-24 is the mandatory EN 16931 field that declares which specification — the base standard, a CIUS (like XRechnung or Peppol BIS), or an extension — an invoice claims to conform to. Validators use it to choose which rule set to apply, so an incorrect value leads to the wrong validation or outright rejection.
Chorus Pro
Chorus Pro is France's government platform for receiving and processing B2G e-invoices, mandatory for all invoices to French public entities.
Codice SDI
The Codice SDI (Codice Destinatario) is a 7-character alphanumeric code that routes FatturaPA invoices to the correct recipient through Italy's SDI system.
EN16931
EN16931 is the European standard for electronic invoicing that defines the semantic data model and business rules all compliant e-invoices must follow.
Endpoint ID
The Endpoint ID is the unique identifier that locates a business on the Peppol network, combining a scheme ID with a national business registration number.
Enterprise Number (Belgium)
The KBO/BCE enterprise number is a unique 10-digit identifier assigned to every business entity registered in Belgium, used as the primary business identifier in Belgian e-invoicing.
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Business Terms (BT)
EN16931 semantic data model fields like BT-1, BT-10, BT-46
BT-1 Invoice Number
BT-1 is the unique sequential identifier assigned to an invoice by the seller, required in every EN 16931 e-invoice.
BT-10 Buyer Reference
BT-10 is a text field in the EN 16931 semantic model where the buyer's reference identifier — such as a purchase order number, project code, or routing ID — is carried on the invoice. Optional in EN 16931, but mandatory in key CIUS profiles like XRechnung and Peppol BIS 3.0.
BT-2 Invoice Issue Date
BT-2 is the date when the invoice was issued by the seller, mandatory in every EN 16931 e-invoice.
BT-24 Specification Identifier
BT-24 is the mandatory EN 16931 field that declares which specification — the base standard, a CIUS (like XRechnung or Peppol BIS), or an extension — an invoice claims to conform to. Validators use it to choose which rule set to apply, so an incorrect value leads to the wrong validation or outright rejection.
BT-31 Seller VAT Identifier
BT-31 is the seller's VAT registration number, required when the invoice includes VAT and essential for EU intra-community transactions.
BT-34 Seller Electronic Address
BT-34 identifies the seller's electronic address to which application-level responses (such as invoice response messages) may be delivered. In Peppol, this is the seller's endpoint ID used for network routing.
BT-46 Buyer Identifier
BT-46 is an identifier for the buyer, such as a registration number, that helps uniquely identify the purchasing organization.
BT-48 Buyer VAT Identifier
BT-48 is the buyer's VAT registration number, required for intra-community supplies and reverse charge transactions in EU e-invoicing.
BT-49 Buyer Electronic Address
BT-49 identifies the buyer's electronic address to which the invoice is delivered. In Peppol, this is the buyer's endpoint ID — the primary field used for invoice routing across Access Points.
BT-5 Invoice Currency Code
BT-5 is the currency code for all monetary amounts in the invoice, using ISO 4217 three-letter codes like EUR, USD, or GBP.
BT-63 Seller Tax Registration
BT-63 is the seller's tax registration identifier used in countries where a tax registration separate from VAT exists, such as Germany's Steuernummer.
Business Groups (BG)
EN16931 structural groups like BG-4 Seller, BG-7 Buyer
BG-4 Seller
BG-4 is the EN 16931 business group that contains all information identifying and describing the seller (supplier) of goods or services on the invoice.
BG-7 Buyer
BG-7 is the EN 16931 business group that contains all information identifying and describing the buyer (customer) of goods or services on the invoice.
Standards & Formats
EN16931, Peppol BIS, XRechnung, ZUGFeRD, etc.
CIUS (Core Invoice Usage Specification)
A country- or sector-specific customization of the EN 16931 European e-invoicing standard that restricts or refines the core data model without breaking interoperability. Examples include XRechnung (Germany), Peppol BIS 3.0, and CIUS-IT (Italy).
EN16931
EN16931 is the European standard for electronic invoicing that defines the semantic data model and business rules all compliant e-invoices must follow.
Factur-X
Factur-X is the French name for the ZUGFeRD hybrid e-invoice format that embeds structured XML inside a PDF, enabling both human and machine readability.
FatturaPA
FatturaPA is Italy's national e-invoice format required for all B2B and B2G invoicing through the SDI (Sistema di Interscambio) platform.
Hybrid invoice
An invoice that bundles a human-readable PDF and a structured XML representation of the same data into a single file. The PDF is for people; the embedded XML is for software. ZUGFeRD and Factur-X are the two flagship hybrid formats; both use PDF/A-3 as the carrier.
OASIS UBL (Universal Business Language)
OASIS UBL is the open library of standard XML business documents — invoices, orders, despatch advices, catalogues, and more — published by OASIS as an ISO/IEC standard (19845:2015) and used as the XML syntax behind Peppol BIS, EN 16931, and most European e-invoicing CIUSes.
PDF/A-3
An ISO-standardized archival PDF format (ISO 19005-3) that allows embedding files of any type — including XML invoice data. It is the container format that makes ZUGFeRD and Factur-X hybrid invoices possible.
Peppol
Peppol is a European e-invoicing network that enables businesses to exchange electronic documents across borders using a standardized format and secure infrastructure.
Peppol BIS Billing 3.0
Peppol BIS Billing 3.0 is the specific Peppol Business Interoperability Specification for invoices and credit notes — a CIUS of EN 16931 expressed in OASIS UBL 2.1, validated by Schematron, and the de-facto B2G/B2B billing format on the Peppol network.
XRechnung
XRechnung is Germany's national CIUS (Core Invoice Usage Specification) that extends EN16931 with German-specific requirements for B2G e-invoicing.
ZUGFeRD
ZUGFeRD is a German hybrid e-invoice format that embeds structured XML data inside a PDF/A-3 document, making invoices both human-readable and machine-processable.
Infrastructure & Systems
Peppol network, SDI, Chorus Pro, KSeF, etc.
Chorus Pro
Chorus Pro is France's government platform for receiving and processing B2G e-invoices, mandatory for all invoices to French public entities.
Four Corner Model
The Four Corner Model is the federated network architecture used by Peppol, where invoices travel from sender through two intermediary Access Points to the receiver.
KSeF
KSeF (Krajowy System e-Faktur) is Poland's national e-invoice system that will become mandatory for all B2B invoicing in February 2026.
OpenPeppol
OpenPeppol AISBL is the Belgian non-profit association that owns, governs, and develops the Peppol network — publishing the BIS specifications, code lists, and validation artefacts, and accrediting Peppol Authorities and Service Providers worldwide.
Peppol Access Point
A Peppol Access Point is a certified service provider that connects businesses to the Peppol network, handling message routing, AS4 transport, SMP registration, and delivery receipts.
PPF (Portail Public de Facturation)
The French government's public e-invoicing portal that serves as the central directory and data concentrator for France's mandatory B2B e-invoicing reform launching September 2026.
SDI (Sistema di Interscambio)
SDI is Italy's central government platform that receives, validates, and routes all electronic invoices for both B2B and B2G transactions.
Verifactu
Spain's certified invoicing system operated by the AEAT (tax agency) that requires all billing software to produce tamper-evident, hash-chained invoice records — with optional real-time submission to the tax authority.
Technical Concepts
schemeID, EndpointID, AS4, XAdES, etc.
Digital signature (e-invoicing)
A cryptographic signature applied to an e-invoice (or its XML/PDF carrier) to guarantee authenticity of origin and integrity of content. In several EU CTC regimes — notably Italy's SDI and France's Chorus Pro — a qualified or advanced electronic signature is mandatory; in EN 16931 itself it is optional.
PDF/A-3
PDF/A-3 (ISO 19005-3) is an archival PDF format that allows embedded file attachments, making it the required container format for ZUGFeRD and Factur-X hybrid e-invoices.
Post-Audit Model
The traditional VAT compliance model where invoices are exchanged privately between seller and buyer, and the tax authority only inspects them during periodic or triggered audits. It is the model that Continuous Transaction Controls (CTC) — clearance and real-time reporting — are progressively replacing.
QR code (e-invoice)
A 2D barcode embedded on or alongside an electronic invoice that encodes a compact, machine-readable summary of the invoice — typically issuer VAT, total, VAT amount, timestamp, and a cryptographic hash. Mandatory in several CTC regimes (notably Saudi Arabia ZATCA and India), optional in most EU formats.
Real-Time Reporting
A Continuous Transaction Controls (CTC) model in which invoice data is transmitted to the tax authority within minutes or hours of invoice issuance — but after the invoice has already been exchanged with the buyer. Unlike clearance, real-time reporting does not block or pre-approve the invoice; it runs in parallel.
Schematron
Schematron is an XML-based validation language that checks business rules in e-invoices using XPath expressions, producing specific error codes when conditions fail.
Business Concepts
Credit notes, reverse charge, self-billing, etc.
e-Reporting
France's mandatory obligation to electronically report transaction data (B2C sales, cross-border transactions) to the tax authority via the PPF — a parallel track to e-invoicing that covers transactions outside the domestic B2B scope.
Evidence Pack
An Evidence Pack is Invoice Navigator's structured compliance certificate that documents the complete validation, remediation, and revalidation chain for an e-invoice.
Country Identifiers
KVK, Leitweg-ID, SIRET, NIP, etc.
Codice SDI
The Codice SDI (Codice Destinatario) is a 7-character alphanumeric code that routes FatturaPA invoices to the correct recipient through Italy's SDI system.
Endpoint ID
The Endpoint ID is the unique identifier that locates a business on the Peppol network, combining a scheme ID with a national business registration number.
Enterprise Number (Belgium)
The KBO/BCE enterprise number is a unique 10-digit identifier assigned to every business entity registered in Belgium, used as the primary business identifier in Belgian e-invoicing.
GLN (Global Location Number)
A 13-digit GS1 identifier that uniquely identifies a legal entity, function, or physical location — widely used as a Peppol participant ID under ISO 6523 scheme 0088, particularly in retail, healthcare, and logistics.
KVK Number
The KVK number is an 8-digit Dutch Chamber of Commerce registration number that uniquely identifies businesses registered in the Netherlands, widely used as the primary Peppol identifier.
Leitweg-ID
A structured routing identifier used in German public-sector e-invoicing to direct XRechnung invoices to the correct government entity and internal department. Mapped to the BT-10 (Buyer Reference) field.
NIF/CIF
NIF and CIF are Spanish tax identification numbers — NIF for individuals and CIF for companies — required on all Spanish e-invoices.
NIP
NIP is the Polish tax identification number (Numer Identyfikacji Podatkowej), a 10-digit code required for all B2B e-invoicing through KSeF.
Partita IVA
The Italian VAT identification number — an 11-digit numeric code issued by the Agenzia delle Entrate that identifies a business or self-employed professional for VAT purposes and is mandatory on every invoice routed through the SDI.
Peppol ID
A Peppol ID is a participant identifier on the Peppol network, composed of an ISO 6523 scheme ID and a national business registration number.
Scheme ID
A Scheme ID is a code that identifies the type of business identifier used in an e-invoice, such as a VAT number, chamber of commerce registration, or national enterprise number.
SIREN
The 9-digit French business identification number issued by INSEE that identifies a legal entity as a whole — the root identifier from which SIRET establishment numbers and the French VAT number are derived.
SIRET Number
SIRET is a 14-digit French establishment identification number (SIREN 9 + NIC 5) that uniquely identifies a specific business location, used in Factur-X and PDP-based e-invoicing.
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