Does the ESEF iXBRL Previewer Link resemble your PDF Annual Report?

April 22, 2022by Team IRIS CARBON

This year, it is mandatory for companies across the EU and UK regions to submit their 2021 annual reports in the ESEF iXBRL format. It is important for companies to ensure that their iXBRL documents are error-free because going forward, those iXBRL documents will be considered as companies’ official documents from a compliance perspective.

The consumers of iXBRL documents typically include regulators, government agencies, investment rating agencies, analysts, and investors who compare potential investments to identify opportunities. The main advantages of iXBRL are better accessibility, visibility, and transparency of XBRL data due to the human- and machine-readable layers.

The number of ESEF 2021 filings submitted until now is more than 2,700. All those filings have been made public through a repository ( that displays them in an iXBRL viewer format. The iXBRL previewer link allows users to view XBRL tags and their properties in a human-readable manner.

How The iXBRL Format Works

Inline XBRL or iXBRL is an open standard for reporting structured data in a human-readable format. The iXBRL format is used by companies across geographies for financial reporting purposes. Regulators, investors, and analysts can easily access iXBRL reports and use them to analyze and compare corporate disclosures for decision-making. An iXBRL document has an HTML layer with XBRL tags embedded and it retains the stylization and formatting of an annual report.

Let’s understand how XBRL data appears in the HTML format. For example, the fact-value 394 is reported in a “Balance Sheet” for the period 2020. The details of the fact-value (XBRL tag and its properties) can be viewed by clicking on any value within the report as shown in the screenshot below. It represents the following:

Line item – Cash and Cash equivalents

XBRL tag – ifrs-full:CashAndCashEquivalents

Fact value – 394

Period – 31-12-2020

Scale – Thousand

Currency – EURO

View Narrative Information

Entity-specific information can be viewed and verified easily. For instance, see the name of the parent entity in the screenshot below.

View Block Tagging Of Notes

Additionally, it can also be verified if an issuer has done block tagging of notes for a reporting period. Details about the XBRL tag used and the text block content can be visually seen in the previewer link.

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xHTML Should Mirror Your PDF Report

The iXBRL previewer link is interactive in nature and can be used to access information within the annual report. It also retains the stylization and formatting of the PDF report. Moreover, the PDF of an ESEF iXBRL report should be in a searchable format without any images, embedded links, or external references. The size of the final xHTML document should not exceed 100 MB. By following these guidelines, companies can ensure their ESEF iXBRL document is easily accessible and usable.

Example of an iXBRL report that does not match with the PDF report

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Example of an iXBRL report that matches the PDF report

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Quick Tip

Once the ESEF iXBRL report is finalized and submitted to the national regulator, the next step for the company is to publish its iXBRL zip package on its website along with the iXBRL previewer link and PDF report.


Companies must not compromise on the style and design of their ESEF iXBRL documents since those are their official documents for reporting purposes. iXBRL makes reports more accessible, and easy to analyze and compare. Any inefficiency in the HTML layer of a report can slow down the previewer link and affect its use.

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