If your company's financial year started on or after 1 January, 2025, classic-XBRL filing with the KVK is no longer an option. For large entities, the path forward is Inline XBRL (iXBRL). Most companies with calendar-year-ends need to file by April, and the clock is ticking toward the filing window.
The KVK mandate eliminates email and postal filing entirely, so without proper iXBRL software, you will not be able to file your annual report. If you're still evaluating software in March, you're cutting it close.
What the mandate requires
The shift to iXBRL requires key capabilities your current standard accounting software doesn't have:
- Tagging financial data to match the KVK taxonomy. Every line item needs a corresponding XBRL tag.
- Creating extensions for company-specific items not covered in the standard taxonomy. Most medium and large companies need these.
- Anchoring extensions correctly to standard elements. Each custom tag must reference a broader or narrower concept from the official taxonomy.
- Validating against KVK technical requirements before submission. The system will reject files with errors.
Who needs to file in iXBRL
The mandate targets large BVs, NVs, cooperatives, and mutual insurance societies that previously filed via PDF. You're required to use iXBRL if you prepare statements under IFRS, use NL-GAAP with entity-specific disclosures, or modify standard financial statement layouts.
Companies are classified as "large" if they meet two of three criteria for two consecutive years: balance sheet exceeding €25 million, turnover exceeding €50 million, or 250+ employees. Medium-sized companies have lower thresholds.
What software needs to do
You need software that can handle the entire iXBRL workflow and generate the mandatory filing information:
- Import your annual report, apply XBRL tags to financial statement line items, and convert your PDF or Word document into compliant XHTML
- Create and manage extensions for company-specific items with proper anchoring
- Generate the report package in the correct format with all supporting files
- Validate against KVK requirements before submission
Many accounting packages offer basic XBRL export, but not the full iXBRL report package functionality required for KVK filing. Verify carefully that your chosen solution handles extensions and anchoring.
Validating before submission
Before you submit to the KVK, you need confidence that your iXBRL file is technically correct. Discovering errors after submission wastes time: the KVK system will reject files that don't validate.
Apart from our XBRL Tagger, our free XBRL Vision tool also validates iXBRL files against Dutch taxonomy requirements. It runs entirely in your browser, your data never leaves your device. The tool checks technical structure, correct application of taxonomy elements, calculation relationships, currency specifications, and extension anchoring.
This provides an independent check that what you've created will be accepted by KVK and helps auditors verify files meet NBA Alert 50 requirements for Dutch professional standards.
The timeline and next steps
The mandate is operational now. Your finance team needs time to understand tagging, review extension requirements, and validate output. Companies starting now have this time at their advantage. Those who wait until late spring may already be facing last-minute pressure.
If you're working with external accountants or auditors, coordinate early and be one step ahead. The auditor's report must be included in the digital file.
Beyond bolt-On tagging
Many companies approaching the KVK mandate look for tagging services or tools that bolt onto their existing reporting process. You send your finished PDF or Word document to a service provider, they add XBRL tags, and you file the result.
This solves the immediate compliance problem. But it creates a fragmented workflow where your source document and the filed iXBRL version are separate artifacts. When something needs updating, you change the source document, then send it back for re-tagging. The XBRL layer sits outside your actual reporting process.
The alternative is integrated disclosure management: treating iXBRL filing as part of your report creation workflow, not as a post-production step.
With Disclosure Management, you maintain one source of truth. Financial data flows from your accounting system. You draft narrative content. You apply tags as part of the authoring process, not afterwards. When your CFO requests a change, you make it once, and every output format, iXBRL for KVK or a PDF for stakeholders, updates automatically.
This matters more as requirements expand. Block tagging notes will become mandatory. If you're subject to CSRD, sustainability reporting will need tagging. If you have operations across Europe, you're managing multiple jurisdictions: Dutch KVK, UK Companies House, ESEF for consolidated statements.
Bolt-on tagging multiplies effort with each new requirement. Integrated disclosure management scales: you're already working on a platform designed for structured reporting across multiple formats and jurisdictions.
The KVK mandate creates momentum to evaluate your reporting infrastructure. You need to implement something to be ready for April. The question is whether that implementation positions you for the next five years of European reporting requirements, or just gets you through this year's filing.
How we can help
We've been working with iXBRL across European jurisdictions for years. The Dutch KVK requirement is the latest implementation of digital structured reporting, not our first.
Our approach:
Tools designed for European structured reporting that handle Dutch KVK requirements alongside ESEF, UKSEF, and other mandates.
Support that understands both technical requirements and practical workflows: How finance teams actually prepare annual reports.
Local expertise that knows how Dutch companies structure financial statements and which extensions commonly arise.
We're here to help you meet the KVK filing requirements and deadline correctly. The compliance journey doesn't need to be complicated, but it does need to start soon.
Need help with your KVK iXBRL filing?
To discuss your specific requirements, see how our platform handles the Dutch mandate, or get started with your first filing. The April deadline is approaching!
