About XBRL

Open and free standard for business reporting

XBRL is an international digital standard for business reporting to regulators, governments and registries, used in more than 50 countries. Its design enables communication of many types of high-quality, universally-understood, business data and metadata between organisations. It is open and free to use, so meets national and international transparency and openness requirements.

What is XBRL?

XBRL is used to describe, capture and move digital business data. “XBRL taxonomies” are used to define the data, and “XBRL reports” are used to exchange the data. XBRL software combines the report and the taxonomy to validate the data and allow consistent interpretation by people and computers.

The features of XBRL solve the problems of communicating complex business data from one system or organisation to another. It is used widely throughout the world with national XBRL data programmes that cover annual financial reports, tax reporting and reporting of prudential, statistical and other regulatory data. Many millions of XBRL reports have been created, and it has become the standard of choice for digitisation where Excel and PDF would previously have been used.

XBRL as we know it today is primarily based on the XBRL 2.1 specification, published in final form (a “Recommendation”) on 31st December 2003. Since then, XBRL International has led the evolution of the standard to meet a wide variety of needs. CoreFiling has taken a leading role in the development of the standard, keeping it fresh and relevant to the needs of business data collectors and providers.

XBRL reporting programmes

A typical XBRL implementation supports a business-to-government data collection programme, as shown below. The XBRL taxonomy and XBRL report are used to communicate between the parties in a standardised way, ensuring that the data request and the data itself is understood by all parties involved in enacting the legislation or other filing requirement.

It is normal for each role to be played by a different organisational stakeholder. We can see this by looking at some live filing programmes.

The XBRL Specifications

The variability of the stakeholders and their specific needs have driven the XBRL standards to provide a multitude of features. These features come together in the XBRL Standard to solve the problem of communicating business data.

Significant features will typically have their own specification, which describes the rules and syntax required to use the feature in a standardised way that any compliant XBRL software can understand.

  • How to describe the dimensional model -> XBRL 2.1 and XBRL Dimensions 1.0 specifications
  • How to display data in a spreadsheet -> Table Linkbase specification
  • How to define and execute business data rules -> XBRL Formula specification
  • How to create an XBRL report that looks like a traditional business report -> Inline XBRL specification

XBRL International Inc. (XII) governs the standard to oversee its development and provide authoritative support for users. Active members of XII (such as CoreFiling) participate in working groups, boards and task forces to carry out the work required. XII provides certification that XBRL products meet the specifications required to work with XBRL.

The design of XBRL

Looking at the original use case for XBRL we can gain an understanding of its foundation

If we look at the “363,165” figure in this simple mockup of a typical business report, we are able to obtain a good understanding of what this figure represents. This format has been refined and perfected over time to be informative and easy to read. Reading this report relies on human intuition and learning and, for a computer, we need to be more explicit. XBRL’s design centres on the idea of a “standalone fact”, that is, a number that can be fully understood on its own.

A representation of a standalone fact in an XBRL report is below. Each and every useful piece of context about the figure is explicitly attached. This makes computer processing of the business data easier and more consistent.

The digital data standard, in this case the US GAAP taxonomy, contains even more information to ensure the fact is unambiguous and can be understood and used properly. If we look at the taxonomy, we can see that:

  • The value represents a monetary amount (as opposed to, for example, percentage, text or date content)
  • “Operating expenses” are defined in the external reference: IAS 1, 2022-03-24, Paragraph 85
  • “Consolidated accounts” is selected instead of alternatives parts of the breakdown such as “Operating segment”

XBRL vs. alternatives

Every file format and data exchange technology has its own strengths. In the table below, we contrast XBRL with a common alternative, XML, to demonstrate particular strong points of XBRL.

Characteristic XML XBRL
Data quality Basic syntax checks are included, business rules are documented only and must be implemented. Several layers of quality checks runnable by standards-based processors are built in.
Viewing data Relies on custom code to display data to the user. How the data should be rendered is built in to the standard.
Communication XML schema must be accompanied by documentation such as message implementation guides and data dictionaries. A single XBRL taxonomy package with standardised content contains everything required to create messages.
Software support Low level, developer support requires custom applications to make usable. Standards-based business software is available for use with any data set.
Data is long-lived As documentation, schema and processing change, old XML files become an unreliable source. Explicitly tied to a single taxonomy, XBRL documents retain their integrity over a long period.
Data structures XML uses a hierarchical data structure that is limited in its application to business data. XBRL supports the dimensional and hierarchical structures commonly found in business data.
Fidelity of information Data items usually missing key information such as precision and time-based information. Captures every aspect of a piece of business data that is needed for proper analysis.


From the above table, we can see the strengths of XBRL in providing a solution for a myriad of business requirements entirely within a single standard.

It is common to see XBRL, XML and other technologies used side-by-side to meet different data needs. Transactional messages such as updating contact details are well suited to XML, whereas XBRL delivers long-lived, unambiguous, highly-functional, data to create documents of record. Once data gets more complex and multiple parties are involved, XBRL cannot be beaten for its flexibility and quality.

How CoreFiling use XBRL

At CoreFiling, our approach has always been to implement the specifications first and then build integration layers and business applications on top of this. A major benefit to this approach is that it leads to extremely robust solutions that guarantee interoperability with other XBRL compliant software. This gives confidence to customers such as national regulators that they are collecting good quality, useful data. Another benefit is the very short lead time from when a data standard is released to when it is available for our corporate and financial customers to use. Building on our core XBRL processor in this way, we have developed applications that cover the entire reporting ecosystem.

Our recent investment and development takes use of the technology further. Strong data models, standardised computing layers and the easy movement of data are not just applicable to data collection. It provides an entire model-backed data management approach which provides low cost, high-quality and highly-traceable data handling. Data captured by our True North Data Platform is put to work using model-backed data services. These are driven by the standardised data definitions to provide data processing and access for any business data.

Despite the many benefits from using XBRL, for most of our solutions, there is no need to know about the standard. We support filing programmes where filers exclusively use Excel, with XBRL providing efficiency and data quality behind the scenes. This is key to our approach to XBRL: hide the complexity and leverage the power. We are always pushing the boundaries of the technology with industry partners and look forward to more XBRL in the future.

More resources

The CoreFiling taxonomy library (BigFoot) allows you to browse hundreds of XBRL taxonomies.

This Report on data quality in Solvency II reporting covers improvements made by EIOPA during six years of XBRL reporting.

The XBRL technical specifications provide the basis for the open and free XBRL standards.

Members of XBRL international have full access to XBRL guidance and best practice.

The XBRL Glossary is a vital companion for those who want a bridge between business and technical terminology.

Several diverse public data sets in XBRL are available online, including SEC corporate filings and Bank of Spain data from credit institutions.

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