For decades, the final step of the annual reporting cycle for Finnish companies has been a predictable, if somewhat manual, ritual: converting a carefully crafted document into a PDF and uploading it to the Finnish Patent and Registration Office (PRH).
But as of January 1, 2026, that ritual is coming to a definitive end.
The new Finnish Trade Register Act marks a paradigm shift in how corporate Finland communicates with regulators, investors, and the public. We are moving away from “documents” and toward “structured data.” This is the dawn of the Inline XBRL (iXBRL) era in Finland—a transition that promises faster registration, improved access to credit, and a future-proofed reporting workflow.
Whether you are a Finnish controller, a CFO of a multinational subsidiary, or an auditor, this guide breaks down everything you need to know to navigate the 2026 mandate with confidence.
What Exactly is the 2026 PRH Mandate?
The mandate is a multi-year rollout that fundamentally changes the delivery and format of statutory filings in Finland. Unlike the previous voluntary system, the PRH is now empowered to enforce digital-first reporting through the Finnish Business Information System (YTJ).
The Timeline: A Staggered Revolution
- January 1, 2026: All companies (except private traders and foundations) must file notifications, applications, and financial statements online via ytj.fi. Paper submissions received after this date will simply not be processed.
- Financial Year 2027: The formal obligation for structured iXBRL reporting kicks in for most limited liability companies and cooperatives.
- 2028 and Beyond: The “annual verification” requirement begins. If a company fails to verify its registered details annually, the PRH can impose a negligence fee of €300 (or €600 for public limited companies).
The Format: Why iXBRL?
The PRH is moving to Inline XBRL (iXBRL). Think of iXBRL as a “hybrid” format. To the human eye, it looks like a standard, well-designed webpage (XHTML). To a machine, however, it contains hidden “tags” that identify exactly what every number represents—whether it’s Liikevaihto (Revenue) or Oma pääoma (Equity).
Why the Shift to “Data-First” Reporting Matters
If you view this mandate as just another compliance “chore,” you’re missing the strategic advantage. Transitioning to a data-first approach offers three transformative benefits:
A. Faster Access to Capital and Credit
Because iXBRL data is machine-readable, it can be processed by banks and credit rating agencies almost instantly. In Finland’s competitive landscape, being the first to have your registered financial status updated on services like Virre can significantly speed up financing approvals.
B. Global Transparency, Local Language
Since XBRL tags are based on a standardized Finnish National Taxonomy (SBR), a foreign investor can use automated tools to read your Finnish financial statements in their own language. The “data” speaks for itself, removing the language barrier to international investment.
C. Eliminating “Last-Mile” Human Error
The PRH’s online filing system includes built-in validation rules. If you try to file a report with a missing mandatory disclosure or a calculation error, the system catches it before you submit. This eliminates the dreaded rejection letter and the subsequent late filing fees (which can reach €600).
The “Accountant’s Burden”: Digital Assurance and SBR
One of the most significant changes in the Finnish mandate is the impact on the Statutory Audit.
Starting in the 2027 cycle, auditors will be required to provide assurance not just on the numbers, but on the digital tags themselves. This means the auditor must verify that the Oma pääoma tag is actually attached to the correct equity figure in the iXBRL instance.
For accounting firms, this creates a “Review Gap.” Auditing raw XBRL code is impossible for a human. Firms will need to adopt SBR Viewers—like the one integrated into IRIS CARBON®—to render the digital code back into a readable format for review and digital sign-off.
Preparing for 2026: A Checklist for Finnish Finance Teams
The road to January 1, 2026, requires a mix of technical and procedural preparation.
- Audit Your Software: Does your current accounting or ERP system have a REST API connection to the PRH’s XBRL interface? If not, you will need a specialized Disclosure Management platform.
- Verify Your Authentication: Ensure your board members have strong authentication (Finnish bank IDs or mobile certificates) ready to sign off on the new digital YTJ forms.
- Map Your Taxonomy Early: Don’t wait until 2027 to understand the SBR Taxonomy. Begin “shadow-tagging” your 2025 reports to see where your current chart of accounts might clash with the new structured definitions.
- Consolidate CSRD and SBR: If you are a large entity, you will also be facing CSRD (Sustainability) tagging mandates. Use a platform that handles both to avoid doubling your workload.
Why IRIS CARBON® for Finnish Reporting
Transitioning to iXBRL doesn’t have to be a technical nightmare. At IRIS CARBON®, we’ve helped thousands of companies globally navigate the move from PDF to structured data.
- Managed Mapping Services: Our experts handle the initial mapping of your Finnish accounts to the National Taxonomy, so you don’t have to learn a new language.
- PRH REST API Integration: Skip the manual uploads. Our platform connects directly to the PRH’s XBRL interface for secure, system-to-system submission.
- Built-in Auditor Workflow: Invite your RAs directly into the platform. They can review tags, leave comments, and provide digital assurance in a single, secure environment.
Conclusion: Embrace the Real-Time Economy
The 2026 PRH mandate is more than a change in filing format; it is a step toward a Real-Time Economy where Finnish businesses are more transparent, agile, and globally connected.
By moving from PDF to “Data-First” reporting today, you aren’t just checking a compliance box—you’re giving your company a competitive edge in the digital age.
