Overview
SIST-TS CEN/TS 16931-13:2026 provides the functional specification and guidance for the eInvoice Registry dedicated to managing Core Invoice Usage Specifications (CIUS) and Extension Specifications within the European electronic invoicing (eInvoicing) framework. Developed by the Slovenian Institute for Standardization (SIST) and following CEN technical committee guidance, this document establishes a structured, transparent, and publicly accessible approach for the discovery, registration, and management of specifications that either restrict or extend the Core Invoice Model defined in EN 16931-1.
The standard is aligned with the requirements of Directive 2014/55/EU, supporting interoperability, harmonization, and efficiency for electronic invoicing processes across the EU and related markets.
Key Terms:
eInvoice Registry, CIUS, Extension Specifications, EN 16931, semantic interoperability, governance, electronic invoicing standard
Key Topics
Purpose and Role of the eInvoice Registry
- Centralized repository: The Registry serves as a searchable, structured database where CIUS and Extension Specifications can be discovered, registered, updated, and managed by stakeholders.
- Transparency and alignment: It promotes semantic alignment in eInvoicing by providing visibility into sector- and country-specific requirements and solutions, reducing unnecessary duplications and encouraging reuse.
- Complementary resource: While the Registry is not a legal authority, it supports both public and private sectors in aligning with EN 16931-1, providing reference links to definitive specification documents.
Scope of Registry Services
The standard defines:
- The structure and capabilities of the Registry
- Types of artefacts managed (CIUS, Extension Specifications, code lists, validation artefacts)
- Submission and verification processes for specifications
- A governance model with clearly defined roles and responsibilities
- Functional requirements to ensure Registry efficiency and sustainability
Governance and Maintenance
- Governance structure: Responsibilities are distributed among the Registration Authority (RA), Registry Management Group (RMG), Standards Evaluation Group (SEG), Registry Operator (RO), and Submitters.
- Verification process: Ensures all registered specifications meet legal, technical, and interoperability requirements, with submitters responsible for ongoing compliance and updates.
- Stakeholder engagement: All users, including public authorities, enterprises, and service providers, have access for discovery and downloading, while submissions are managed through structured review.
Applications
SIST-TS CEN/TS 16931-13:2026 holds practical value for:
- Public administrations and contracting authorities: Ensuring compliance with EU directives on electronic invoicing in procurement and fostering efficient cross-border operations.
- Industry sectors: Adapting invoice models for sector-specific or national needs by referencing and reusing established CIUS and Extension Specifications from the Registry.
- Software vendors and integrators: Integrating Registry content for electronic invoice generation, validation, and interoperability between systems.
- Standardization bodies and business associations: Monitoring developments and fostering best practices by referencing the centralized artefacts and validation tools maintained in the Registry.
The Registry enables organizations to:
- Locate and evaluate conformant invoice specifications relevant to their operations
- Avoid reinventing specification artefacts by adopting or adapting existing solutions
- Manage and update their specifications transparently, supporting ecosystem-wide interoperability
Related Standards
SIST-TS CEN/TS 16931-13:2026 functions within a comprehensive standards environment, directly referencing and supporting:
- EN 16931-1: Semantic data model of core invoice elements
- CEN/TS 16931-2: Syntaxes compliant with EN 16931-1
- CEN/TS 16931-5: Guidance on the use and methodology of sector or country invoice extensions
- CEN/TR 16931-10: Extension requirements for B2B invoicing
- Other supporting documents: Syntax bindings and guidelines for interoperability (CEN/TS 16931-3, -4, -6, -7)
Together, these standards create a robust framework for scalable, interoperable and future-proof electronic invoicing solutions throughout the European and global commercial environment.
Keywords: electronic invoicing, CIUS, Extension Specifications, eInvoice Registry, EN 16931, interoperability, registry governance, validation artefacts, sector extensions, European standardization