If you’re preparing for the new e-invoicing mandate or just want a clearer understanding of electronic invoice processes, you’re in the right place. This glossary of terms is designed to help you master the essential e-invoicing terminology, understand technical specifications, and navigate compliance with confidence. Whether you’re a business owner, an e-invoicing service provider, or a finance professional, this guide makes sense of it all—so you can stay ahead in a world of digital invoice processing.
API
Application Programming Interface. A programming interface that enables electronic business documents to be exchanged automatically between systems. In e-invoicing, an API allows your invoicing system to transmit and receive electronic invoices with trading partners, streamlining the exchange of invoices and reducing manual entry. APIs help ensure integration of the invoicing process with accounting software for seamless invoice processing.
CII
Cross Industry Invoice. A standard XML syntax for electronic business data. Used in formats like ZUGFeRD and XRechnung, CII defines the core elements of an electronic invoice, ensuring interoperability in pan-European electronic transactions and compliance with EU directives on electronic procurement.
ebInterface
Austria’s standard electronic invoice format, based on XML. Designed to ensure consistent document format and compatibility across systems, it supports efficient electronic exchange of invoice data with service providers and trading partners.
EDIFACT
United Nations standard for Electronic Data Interchange (EDI) in commerce and transport. While not a permitted e-invoicing format in Germany, it can be converted for local compliance. EDIFACT supports secure electronic transactions, reducing errors in invoice and payment terms communication.
EHF (Elektronisk Handelsformat)
Norway’s standard electronic invoice format using XML in Universal Business Language (UBL) syntax. Registration with ELMA is required domestically. For cross-border public procurement, PEPPOL BIS ensures standardised electronic billing and invoice transmission.
E-Invoicing
Short for Electronic Invoicing. Refers to the entire e-invoicing process—receiving, processing, and sending electronic invoices in a machine-readable electronic format such as XML. E-invoicing improves compliance with tax authorities, streamlines electronic payment, and reduces errors in invoice data entry.
E-Invoice / Electronic Invoice
A structured, XML-based invoice that is machine-readable and mandatory in Germany starting 2025. Unlike a simple PDF, an electronic invoice enables end-to-end automated processing, meeting strict technical specifications and supporting electronic signature requirements for authenticity.
FacturaE
Spain’s national e-invoice format, based on XML. Ensures standardised exchange of electronic invoices with trading partners and tax authorities, aligning with EU e-invoicing standards for public procurement and B2B transactions.
Factur-X
A hybrid e-invoice format combining a PDF/A-3 file with embedded XML in CII syntax. Developed as a German-French standard, it delivers both human-readable and machine-readable electronic invoice formats, supporting invoice storage and legal archiving.
FatturaPA
Italy’s electronic invoice standard for public procurement. Based on XML, it meets national legal requirements and ensures interoperability for electronic transactions between businesses and tax authorities.
Finvoice
Finland’s e-invoice format for banking and B2B transactions, using XML for structured data. Compliant with the European e-invoicing standard (EN 16931) from version 3.0 onwards, supporting reliable electronic billing.
KSeF
Poland’s national platform for electronic invoicing (Krajowy System e-Faktur). It enables secure electronic exchangeand storage of invoice data, improving compliance and simplifying e-invoicing adoption.
NAV-System
Hungary’s clearing system provided by the tax authorities (NAV). All e-invoices must be reported through this system, ensuring proper invoice tracking and compliance with local e-invoicing mandate regulations.
EN 16931 Standard
A European e-invoicing standard defining the core elements of an electronic invoice for public procurement. It ensures consistent technical specification and promotes interoperability across EU member states.
OIOUBL
Denmark’s e-invoice standard using Universal Business Language (UBL) XML syntax. Ensures compatibility and structured electronic document exchange between trading partners and service providers.
PEPPOL
Pan-European Public Procurement OnLine. A network that standardises the exchange of electronic invoices across borders. Using certified service providers and PEPPOL Access Points, businesses can transmit invoices securely for public procurement and B2B transactions.
>> Lobster’s Data Product Invoicing includes its own PEPPOL Access Point, simplifying cross-border e-invoicing.
PEPPOL BIS
Business Interoperability Specifications. Defines the format of an electronic invoice for PEPPOL. Uses XML in UBL syntax to ensure standardisation and reliable electronic exchange across the EU.
PDF/A
Short for Portable Document Format Archivable. A subtype of PDF (Portable Document Format) that has been specially optimised for the long-term archiving of documents.
PDF/A-3
Archivable PDF formats designed for long-term storage. PDF/A-3 enables embedding of XML for hybrid electronic invoices like ZUGFeRD and Factur-X, combining human-readable and machine-readable data for seamless invoiceprocessing.
Directive 2014/55/EU
The EU directive mandating electronic invoicing in public procurement. Establishes technical specifications and a consistent set of rules across member states to deliver trade facilitation and electronic business.
UBL (Universal Business Language)
A standard for e-invoicing, defining XML syntax for electronic business documents. Used in XRechnung and OIOUBL to ensure consistent invoice formatting and cross-border compatibility.
ViDA (VAT in the Digital Age)
An EU initiative to harmonise VAT systems, facilitate electronic transactions, and reduce fraud. Supports greater standardisation in e-invoicing and e-reporting to modernise electronic business processes.
XML (Extensible Markup Language)
A markup language for structuring invoice data in text files. Forms the backbone of most e-invoicing formats, enabling machine-readable electronic documents and seamless electronic exchange with trading partners.
XRechnung
A German electronic invoice format using XML in CII or UBL syntax. Compliant with the EN 16931 European e-invoicing standard, it supports public procurement and B2B transactions while ensuring proper invoice storage of the electronic invoice during retention periods.
ZUGFeRD
Germany’s hybrid e-invoice standard combining a PDF/A-3 file with embedded XML in CII syntax. From version 2.0.1 onward, it’s a standard for e-invoicing in Germany, ensuring easy transmission and secure storage of the electronic invoice for compliance with EU rules.
Complicated? It Doesn’t Have to Be. Make (E-)Invoicing Easy with Lobster
You don’t need to be an expert in e-invoicing terminology to comply with the new e-invoicing mandate. Lobster’s electronic invoicing system—our Data Product Invoicing—simplifies, automates, and digitises your entire invoicing process:
- Supports all major national and international e-invoice formats
- Automatic invoice verification
- Connects to PEPPOL, national clearing systems, and service providers
- Seamless integration of the invoicing process with accounting software
- And much more.
Interested?
Get in touch to schedule your demo today and see how easy e-invoicing adoption can be.
Despite conscientious research, we can never completely rule out errors. Are you missing information or have you discovered an error? Then get in touch with us at press@lobster.de.
