Cycle 2.1 Tax File Number (TFN) declaration taxonomy release

Cycle 2.1 TFN declaration taxonomy architecture & harmonisation

Glossary

Cycle 2.1 TFN declaration taxonomy architecture & harmonisation

Taxonomy architecture overview

SBR's taxonomy architecture will grow and evolve over time. Some of the material provided with this taxonomy release is draft and has been included to signal future intent.

A summary of the key taxonomy architecture features is provided below. For more detailed information on the taxonomy architecture, please refer to the SBR taxonomy architecture (version 1.0) taxonomy document, which describes some of the key features and design rationale. The target audience of this document is technical users familiar with the XBRL technology components.

Summary of taxonomy architecture key features

Alignment to natural business data is an important SBR business outcome. Rather than develop the taxonomy from a government agency/forms perspective, the taxonomy is now based on a functional information classification perspective. Only the information classifications relevant to the TFN declaration have been included in SBR's taxonomy architecture
The agencies involved in the SBR project have requirements for financial reports and reports that are transactional in nature. These transactional reports require data elements to be reported with various usage contexts, optionality (sometimes mandatory and sometimes not), complex cross context validation, calculation rules and deeply nested business relationships. These will be described by using both the XBRL taxonomy components and Message Implementation Guideline Specification documents.
Business concepts are re-used across agency forms. The architecture assures that concept definitions only appear once in the information classification taxonomies and are not repeated in agency-specific taxonomies.
Data elements that have been identified as equivalent have been harmonised.
Naming conventions are critical to consistency and harmonisation. The information classification used provides rigorous, repeatable and easy to understand naming conventions.
Rather than use standards specific to a government agency, industry standards have been used. Examples include IFRS (financial), AS4590 (identity), ISO 20022 (finance, health and banking).

Key differences from SBR's Cycle 1 prototype taxonomy

The structure of the taxonomy has changed from an agency and form view, to an information classification view.
The naming conventions have been consistently applied and follow ISO 11179 metadata management principles.
Tuples, dimensions and fully qualified data elements have been used according to a defined rationale.
The AS4590 standard has been applied to name and address information.
Data elements have been classified and harmonised. As such elements are only represented once in the taxonomy and can be reused on any report.

Harmonisation

SBR taxonomy harmonisation aims to reduce the number of reporting elements required to describe the data reported by business to government.

Harmonisation can be achieved by:

rationalisation - identifying elements that are not required to be reported (obsolete or rendundant);
standardisation - redefining elements in order to conform to an endorsed standard;

This can be seen as a top-down approach to harmonisation where conformance is imposed or expected and may involve mapping an element to a defined standard item. The naming of the elements as prescribed by the standard can be adopted.

normalisation - deciding, whether or not elements that seem similar will be treated as equivalent.

This would include the definition of the element, as well as its description.

For the TFN declaration taxonomy, standardisation has been the main focus. Alignment to AS4590 has resulted in increased consistency of data elements where they have been identified as equivalent.

Importantly, data elements defined in the TFN declaration taxonomy can be re-used. For example, the "Address Line 1" data element has been defined once in the taxonomy, but has been re-used four times in TFN declaration report. Using tuples and dimensions, the 70 reported data elements of the TFN declaration report can be created from the 40 data elements defined in the TFN declaration taxonomy.