The global rise of inline XBRL

Inline XBRL (iXBRL) embeds machine-readable data tags directly inside a human-readable HTML document. The same file is, simultaneously, a designed report and a structured data source. After two decades as a niche compliance format, iXBRL has quietly become the standard delivery mechanism for corporate disclosure in most of the world’s largest economies.

What inline XBRL is, and why it matters

FOUNDATIONS XBRL is a global standard for tagging business data. Inline XBRL puts the tags inside the readable HTML document.

Traditional XBRL files were designed for machines rather than people. Inline XBRL combines structured XBRL data with a readable HTML report. This means that people and machines can use the same report.  ¹⁰

The main benefit is that the same report works for both people and machines, while the underlying data remains connected to the information presented in the report. XBRL was originally introduced mainly to meet regulatory requirements, but is increasingly used as a foundation for digital corporate reporting. ⁵

The adoption of XBRL differs across countries. Research shows that this is influenced not only by technology, but also by national regulation, reporting practices and the role of regulators. ¹¹

An inline XBRL example

EXAMPLE What a person sees and what a machine reads are the same file. The tags below sit invisibly inside the readable report.

The easiest way to understand inline XBRL is to look at a fragment. Below is a fictional Consolidated Income Statement. To a human reader it is an ordinary table. To a machine, in the iXBRL publication each figure also carries a tag that names the accounting concept, its currency, its period and its sign — so the value can be extracted and compared across companies without requiring manual data re-entry.

Example: Consolidated Income Statement

To view the example, open this report in the Inline XBRL viewer (new window) and navigate to the Consolidated Income Statement: When you click on a number in the table, the corresponding XBRL information will appear on the right-hand side in the Inline XBRL Viewer

The global picture

iXBRL or some form of structured digital filing is now mandatory for listed-company financial reports in most major economies. The table below summarises the current status across roughly forty jurisdictions.

Europe and ESEF

EUROPE ESEF is the European Single Electronic Format. It makes inline XBRL the obligatory annual-report format across the EEA.

The European Single Electronic Format (ESEF) requires issuers subject to ESEF requirements to publish their annual financial reports in inline XBRL. By the end of 2025, around 3,072 issuers across 30 EEA countries had filed ESEF reports. National regulators conducted around 800 examinations to assess compliance with ESEF requirements. ¹

The table below shows the ten jurisdictions with the largest ESEF filer populations.

Sustainability reporting is also becoming part of European regulatory oversight. By the end of 2025, around 2,000 issuers were subject to enforcement of their CSRD sustainability statements. National regulators also started examining the structured digital reporting of sustainability information.  ¹¹

A similar picture is emerging in the United Kingdom. A 2025/26 review by the Financial Reporting Council (FRC) found that structured digital reporting is now well established and that most filings meet the requirements. However, the FRC continues to identify quality issues, particularly around the consistency and accuracy of tagging. Examples include unnecessary company specific tags and errors in reported earnings per share. The FRC therefore sees structured reporting as an area that requires continuous attention and improvement. ¹²

“Many researchers no longer see iXBRL as a separate format. They describe it as the underlying language of digital corporate reporting.”