ESEF Reporting Software

What Is ESEF Reporting Software?

ESEF reporting software takes the annual report your finance team has finished and produces the digital version that the regulator accepts. The ESEF format requires the report as an XHTML document, with iXBRL tags applied to the consolidated International Financial Reporting Standards (IFRS) financial statements. Listed companies not preparing consolidated IFRS financial statements, still need to comply with the XHTML document requirement, but do not have to apply iXBRL tags.

Those tags make each reported figure machine-readable, so a regulator, an auditor, or an investor can process the same document a person reads in a browser. The software runs the conversion, applies tags from the ESEF taxonomy, and validates the output against ESMA’s rules before you file.

Who Needs ESEF Reporting Software?

ESEF applies to any company with securities admitted to trading on an EU or EEA-regulated market, as well as in the UK. All such companies need ESEF preparation software, to comply with the XHTML format requirement. If your company prepares consolidated financial statements under IFRS, those statements must also carry iXBRL tags in the filing. The requirement covers issuers based in the EU and overseas issuers listed on a European market.

A company files in ESEF through the Officially Appointed Mechanism in its home member state. UK-listed companies meet the same kind of obligation. UKSEF, the FRC’s variant, offers another taxonomy option for UK listed companies who want to apply additional, UK specific, tags to their report . Newly listed companies report in ESEF from their first annual report onwards.

Companies that are not listed on a regulated market, and those that do not prepare consolidated IFRS accounts, fall outside the tagging requirement. Note that listed companies that do not prepare consolidated IFRS accounts, even though they are not required to tag, still require ESEF reporting software to prepare an XHTML annual report.

What Does ESEF Reporting Software Do?

ESEF reporting software covers the full path from a finished report to a filed one, in three stages:

1. 1. Convert: Your annual report goes in as PDF, Word, Excel, or InDesign, and the software renders it as XHTML with the visual design intact.
2. 2. Tag: It applies elements from the ESEF taxonomy through XBRL taxonomies to the primary statements line by line, and the notes as blocks; as an extension of the IFRS Accounting Taxonomy under IFRS, the ESEF taxonomy provides a hierarchical structure to classify financial information as structured data. Where a figure has no match in the base taxonomy, it enables the preparer to create an extension tag and anchors it to the closest base taxonomy element.
3. 3. Validate: A final pass checks the whole filing against the XBRL standard, ESMA’s conformance rules and the filing manual, and flags any errors before the report reaches the regulator.

The Role of AI Assistance

Tagging is the slowest part of ESEF reporting. Every figure in the statements needs the right element from a taxonomy of thousands, and the manual tagging process can introduce manual errors as matching them by hand takes hours. Machine learning takes the first pass.

Seahorse suggests a tag for each line from the patterns in hundreds of thousands of earlier filings, and scores how confident it is in each one. From there, you can accept it, refine it, or reject it, with automated tagging helping streamline the tagging process and reduce risk during review.

Preparing Your Own ESEF Report

You do not have to outsource ESEF reporting. With the right software, your finance team can convert, tag, and validate the report in-house and file it directly. 

This section walks through why some companies bring it in-house, what they need to do it, and how the process runs from start to filing.

Benefits of Bringing Reporting In-House

Bringing ESEF reporting in-house gives your team control over the timeline. You are not waiting on a third party during the busiest weeks of the year, and you can make late changes to the report without a round-trip to a vendor.

The other benefit is the reduced cost – a tagging service charges for each filing, while software has a fixed annual cost that does not increase with each report. From the second year, the cost drops again, because most tagging decisions roll forward and there is far less to redo.

An in-house process also protects your data. Keeping the work in a single platform helps centralise financial data, so updates flow straight into the final tagged report and version-control issues are avoided. The figures in your annual report are price-sensitive until you publish, so they stay on your own systems the whole way.

What You Need

The one thing you cannot do without is the software, and Seahorse is one of the software tools teams need to keep up with changing reporting requirements. It runs as SaaS in the browser, so there is nothing to install, and it keeps up with every change to the ESEF taxonomy and filing rules on your behalf.

You will also need your annual report in a format it accepts, such as Word, Excel, PDF, or InDesign. Since most teams already work in one of these, the report you produce today is ready to go in as it is.

The other thing you need is someone to own the tagging. An accountancy background helps, because tag selection is really about matching each figure to the right accounting concept. The software does the heavy lifting to help ensure compliance, so this person mainly reviews the suggestions and makes the judgement calls.

What You Need to Know

The main thing to expect is that ESEF tagging is a judgement call. The tool proposes a tag for every line, and someone with accounting knowledge checks it against the right IFRS concept. 

The hardest part is the extensions, the figures in your accounts that the base taxonomy has no name for. Expect the first year to take the most work. Every tag is a fresh decision, and a single report can run to several hundred. 

After that, roll-over carries your decisions over each year, and most of them will still be the same, so later filings are far lighter. And remember, the filing only counts once it validates. The report has to pass ESMA’s conformance rules before the regulator accepts it, so build in time to clear whatever the software flags.

Preparing ESEF Reports for Others

Not every company tags its own ESEF report. Many hand the work to a tagging service, an accountancy firm, or a specialist that converts and tags the report on the company’s behalf. On the other side of that arrangement are the firms themselves, who need software built to run ESEF tagging for many clients at once.

This section covers both. We will see what a tagging service is, why a company might use one, and how a provider manages the work and the quality behind it.

What Are Tagging Services?

A tagging service acts as an outsourced digitisation process, taking a company’s finished annual report and returning it as a compliant ESEF filing, tagged, validated, and ready to submit. The company sends its report in Word, Excel, PDF, or InDesign, and the provider handles everything else, using specialist XBRL software to manage the iXBRL format required for compliant submissions.

Most providers are accountancy firms or specialists who tag ESEF reports day in and day out. CoreFiling works through a partner network of these firms, all of whom run the work on Seahorse, so a company gets the same software and validation behind the service whether it tags in-house or hands the job over.

Benefits of Outsourcing Your iXBRL Conversion

Outsourcing makes sense when ESEF is a once-a-year job, and your finance team is already stretched at that point in the calendar. A provider absorbs the work in the weeks when your team has the least room for it.

You also get experience you would otherwise have to build. A firm that tags hundreds of reports knows the judgement calls, the extension decisions, and the validation quirks that slow down a first-time filer. For a company filing its first ESEF report, that experience helps it report faster, shortens the timeline, and lowers the risk of a rejected submission while meeting regulatory compliance expectations.

The provider tracks the taxonomy and the filing rules as well, so you do not have to follow every ESMA update to stay compliant.

Managing the Work

For a firm tagging reports for many clients, the work has to stay organised from one engagement to the next. Seahorse holds each client’s report as its own project while giving teams a single platform for regulatory reporting across clients, with the conversion, tagging, and validation tracked in one place.

A provider can work through several reports in parallel, keep each client’s prior-year tagging on file for roll-over, and document the judgement calls so the company and its auditor can review them later. Nothing lives in a local file on one person’s machine, which supports data integrity when multiple users need to pick up the same engagement as a deadline lands.

Quality Assurance

A tagging service is only worth using if the filing it hands back is correct and ready to submit, and the platform’s validation and review controls help ensure compliance. Every report tagged in Seahorse runs against the same ESMA conformance rules a regulator applies, so the provider catches problems before the filing goes anywhere.

The platform also gives reviewers a full list of every tag applied, which makes a second pair of eyes practical even on a report with over a thousand tags.

A provider can check the tagging for consistency, confirm the extensions are anchored correctly, and hand the company a documented set of decisions alongside the finished file, so consistent review helps reduce risk before submission.

The Tagging Service Workflow

A tagging engagement starts when you send the provider your finished annual report in whatever format you produce it. The provider loads it into Seahorse, where the conversion to XHTML happens straight away, and the tag suggestions give the team a fast first pass at the statements.

From there, the provider works through the tagging, adds any extensions your accounts need, and runs the report against ESMA’s rules until it comes back clean. You get the tagged, validated package back, along with a record of the decisions made, ready to file with your Officially Appointed Mechanism.

Auditing ESEF Reports

ESEF changed the final stage of the audit for EEA listed companies. The auditor now has to give assurance on the digital filing as well as the report itself, and that work lands in the same tight window before signing when everything else is moving too. Note that there currently is no audit requirement for ESEF in the UK, but some auditors offer voluntary assurance.

This section covers what the ESEF audit involves, what an auditor looks for, and how the right preparation and software keep the process from dragging. It also covers Beacon, the tool auditors use to review ESEF filings.

What Auditing Is Required

The auditor’s job is to give assurance on the whole annual financial report, and the ESEF filing is now part of that. They check that the tagging follows the ESEF taxonomy and the reporting manual, and that the figures in the tagged version match the accounts they audited.

The detail that catches teams out is the comparison between documents. The core audit team usually works from a PDF draft while an ESEF specialist works from the tagged package, so the auditor has to confirm that the two are the same report. The ESEF package is what discharges your reporting obligation, so it is the version that has to be right.

How much formal assurance ESEF tagging needs still varies by member state, so it is worth checking what your auditor is required to sign off in your jurisdiction.

Typical Audit Activities

In practice, the ESEF audit runs over several iterations. The preparer shares a version of the package, the auditor raises findings, the preparer addresses them, and a new version comes back for another check.

Each turn brings a specific risk. When the report changes, the tagging has to roll forward onto the new version accurately, and the auditor checks both that the new findings are fixed and that the mark-up they already cleared has not moved. Tables get close attention too, since a PDF source can produce tagging or formatting that is unclear or badly transcribed.

Large reports often keep changing right up to the day of signing, so plans to stop early rarely hold, and every late change to the notes can flag a string of block tags for the auditor to revisit.

Making Life Easy for You and Your Auditor

A few habits make the ESEF audit far smoother, and the software you choose decides how easy they are to follow.

• Share a draft early: Send your auditor a version, even a skeleton one before year-end, so findings come up before the deadline crush.
• Document your judgements: Comment on each tag in Seahorse and export the notes to Excel, so your reasoning reaches the auditor up front and a full audit trail records every change behind it.
• Keep version control tight: Seahorse rolls tagging forward accurately from draft to draft and year to year, so tagging the auditor already cleared stays put when the report changes; centralising updates in one single platform also keeps changes flowing into the final tagged report and avoids version mismatches.
• Get tables right: Seahorse detects tables and brings them into clean, legible form even from a PDF source, where weaker tools fail the reporting manual.

When an auditor raises something awkward late on, CoreFiling’s support team can work through it with you quickly.

Beacon for Audit

Beacon is CoreFiling’s tool for the auditors themselves. Where Seahorse prepares and tags the report, Beacon is what an audit team uses to review and validate it.

It checks a filing against the rules of the target jurisdiction and lists every error and warning, then gives the auditor a full readout of the tagging, a calculation view, and a version-by-version list of what changed between drafts. Reviewers can attach comments to the report, to a validation result, or to a single tag, and export the lot to Excel, split by topic.

Because Beacon and Seahorse run on the same True North platform, the auditor checks against the same rules the preparer did. What you cleared in Seahorse is what the auditor sees in Beacon, which is the single biggest reason the back-and-forth gets shorter.

Integrating iXBRL Reporting Into Your Software Platform

Some teams want ESEF and iXBRL capability inside their own product. A disclosure management platform, an ERP system, or a reporting tool can add it by calling CoreFiling’s engine through an API, so the hard parts come ready-built.

Those hard parts are real. The ESEF taxonomy, the conformance rules, the extension and anchoring logic, and the yearly updates take years to build and maintain. CoreFiling has done that work for more than two decades and exposes it two ways, through Seahorse for document conversion and tagging, and through the full True North Data Platform for everything underneath.

Seahorse – CoreFiling’s ESEF Reporting Software

Seahorse is CoreFiling’s ESEF reporting software, delivered as SaaS for in-house teams and tagging partners alike. It converts your annual report, tags it against the ESEF taxonomy, and validates the result, all in the browser with no installation and always on the current rules.

The features below are what filers and providers use most, from the first conversion through to the roll-over that lightens every year after the first.

Convert Your Annual Report to iXBRL

Upload your finished report in Word, Excel, PDF, or InDesign, and Seahorse converts it to XHTML straight away, supporting the single electronic format ESEF requirement for primary financial reporting. Seahorse keeps the visual design, so the filed document looks like the report your team produced. ESEF uses iXBRL for consolidated reports and XHTML for solo reports.

InDesign users can import through the EPUB export, which smooths the conversion further.

Automated iXBRL Tagging with AI-Assisted Tag Selection

The tag-selection engine is the core of Seahorse, trained on hundreds of past filings. It automates the tagging process and helps teams report faster by proposing a tag for every line with a confidence score, so it clears the obvious items in seconds and leaves your attention for the harder ones.

It also reads how each figure is presented. A number shown in thousands gets the right scale, a bracketed value reads as negative, and automating tag selection reduces manual errors because the engine makes the same call every time.

Fast Table Tagging

Financial statements are mostly tables, and tagging them one cell at a time is slow. Seahorse tags a whole table in one pass, looping through every line and proposing a tag and sign rule for each.

You can review the table as a set, with the full statement in view, and confirm or change the suggestions together. A balance sheet or income statement that would take a long stretch by hand comes together in a fraction of the time.

Block Tagging for Notes to Financial Statements

Seahorse tags the notes in blocks, where a whole section of disclosure takes a single tag. This is the part of ESEF that grew with the Phase 2 mandate, and it covers far more pages than the primary statements.

It handles block tagging and nested block tagging, the case where one tagged section sits inside another. You mark up the notes section by section, and the structure stays intact as you tag.

Built-in Validation Against ESMA Conformance Rules

Every filing runs against the full set of ESMA conformance rules and the ESEF filing manual, so validation supports ESEF compliance with ESMA rules and broader regulatory compliance obligations while Seahorse checks it continuously as you build. Errors and warnings come up in the interface as you go, each one pointing to the tag or data that caused it.

The same step produces the extension taxonomy and the report package ESMA requires, so the output that passes validation is the output you file.

Roll-Over Tagging – Carry Forward Prior Year Decisions

After your first filing, roll-over carries last year’s tagging onto this year’s report. Most line items keep the same tags from one year to the next, so the bulk of the work is done before you start, and the team reviews and updates only what changed.

Roll-over also makes moving to Seahorse easy. Your prior year’s decisions carry into the tool, so a switch does not mean tagging from scratch.

Supported Input Formats

Seahorse works with the formats your report is already in, so your production process does not have to change to suit the software. Whatever your finance team or your design agency hands over goes straight in, and what comes back has to match it exactly.

ESEF Tagging Software and Services Through Our Partner Network

CoreFiling reaches customers through a network of certified partners, mostly accountancy firms and reporting specialists working in their own markets. Whether you want someone to tag your report for you or a Seahorse licence to do it yourself, you arrive through a partner.

The network covers Europe and the UK, so you work with a provider who knows your market, your language, and the filing rules where you report.

Find a Certified ESEF Tagging Service Provider

If you want the work done for you, a certified tagging partner takes your report and returns a tagged, validated filing. Certification means the firm is trained on Seahorse and works to CoreFiling’s standard, so the output holds up.

Many of these partners are accountancy firms that already know your reporting, which keeps the tagging close to the rest of the work they do for you. Tell us where you report and we will introduce you to a tagging partner in your market.

Find a Certified Seahorse Software Provider

If you want to tag in-house, a certified Seahorse provider sets you up with the software and the support to run it. You get the same tool the service providers use, with a partner who handles your licence, your onboarding, and any help you need along the way.

This route suits teams that want to own the process and keep it in-house year after year. Let us know your market, and we will connect you with a Seahorse provider there.

Why Choose CoreFiling for ESEF Reporting?

CoreFiling invented iXBRL and has built eXtensible Business Reporting Language reporting tools for more than 25 years. The same company supplies the regulators and auditors who check ESEF filings, a pedigree no other vendor can claim.

ESEF Reporting Software FAQs

We’ve taken some time to answer some common questions about our ESEF Reporting Software.

Ready to File Your ESEF Report?

Listed companies on EU and UK markets need ESEF reporting software that converts the report, tags it against the ESEF taxonomy, and validates to ESMA’s rules before filing, and the same platform direction also matters as reporting expands from financial reporting into sustainability reporting. Seahorse handles all of it in one platform, backed by a partner network for companies that want to outsource.

Seahorse helps you:

Want to see Seahorse on your own report? Get in touch and we will walk your team through it, or connect you with a certified tagging partner in your market.