Oman Specifications
Release notes for Tax Data Document

Version 1.0.0

Maintained by Oman Tax Authority

Applies to

Oman Tax Data Document

Release Date

2026-04-08

Status

Review

What’s New in This Release

This is the initial release of the Oman Tax Data Document specification. The release includes the following components:

  • Tax Data Document BIS Documentation.

  • Semantic Model.

  • Syntax Binding.

  • Normative Codelists.

  • Tax Data Document-specific Schematron rules.

Overview

This release introduces the first official version of the Oman Tax Data Document Specification.

The specification defines:

  • The Semantic Model (business information requirements).

  • The Syntax Binding (technical representation).

  • BIS documentation and implementation guidance.

  • Applicable normative codelists.

  • Validation artefacts, including Schematron rules.

The objective of this release is to establish a clear and governable framework that ensures semantic consistency, validation accuracy, and implementation certainty for all stakeholders.

Data Model

  • Semantic Model:

    • A Semantic Model in Peppol is a structured, technology-independent representation of the business information, constraints, and relationships required for electronic document exchange, forming the authoritative source for syntax binding, validation rules, and conformance profiles.

      • Business Terms (what the information means).

      • Cardinality rules (how many times information may occur).

      • Data types and formats (how information is represented conceptually).

      • Business rules and constraints (conditions governing usage).

      • Relationships between business elements.

  • Syntax Binding:

    • A Syntax Binding in Peppol is the formally governed, technology-specific mapping of a Semantic Model to a concrete document syntax, defining the exact structural representation, cardinalities, data types, and validation constraints required for an implementation.

      • Technology-Specific Representation.

      • Deterministic Mapping.

      • Normative for Implementation.

      • Constrained by Peppol Governance.

Documentation

  • Peppol Model for Tax Data Document:

    • Introduction and Scope.

    • Audience and Benefits.

    • Business processes.

    • Technical details:

      • BIS Identifiers.

      • Data types.

      • XML Schemas and Namespaces.

      • Glossary.

  • Compliance:

    • Sending Compliance to TDD.

    • Receiving Compliance to TDD.

    • Enveloping Compliance.

Code Lists

  • Standard codelists:

    • ISO3166-1:Alpha2 (Country codes).

    • ISO4217 (Currency codes).

    • UNCL1001 (Credit note type code).

    • UNCL1001 (Invoice type code).

    • EAS (Electronic address scheme).

    • ICD (ISO 6523 ICD list).

  • Tax Data Document:

    • TDD-RR (Tax Data Document Reporting Role).

    • TDD-DS (Tax Data Document Scope).

    • TDD-DTC (Tax Data Document Type Code).

Schematron

Schematron artefacts provide rule-based validation to ensure semantic and technical conformance.

  • OpenPeppol OM TDD Schematron:

    • The Tax Data Document Schematron rules validate structural and choreography-level compliance.

    • These rules ensure that:

      • The document strictly follows the defined Syntax Binding.

      • Only permitted elements and structures are used.

      • No undefined or non-conformant elements are introduced.

    • Their purpose is to guarantee technical conformance to the specified document structure.

Action Items for Implementers

Implementers SHALL perform the following actions to ensure conformance:

  • Review and understand the Semantic Model and the associated Syntax Binding before implementation.

  • Ensure that all code values strictly comply with the applicable normative codelists.

  • Validate implementations against the published validation artefacts, including:

    • XML Schema Definitions (XSD).

    • Schematron rules.

  • Develop the Tax Data Document in full compliance with the Semantic Model, Syntax Binding, and validation artefacts.

  • Notify the relevant Peppol Authority of any identified critical defects, inconsistencies, or required change requests.

Support

For support and clarification:

https://peppol.org/tools-support/service-desk/