Filing iXBRL with the Dutch Chamber of Commerce (KvK): how it works

Have you prepared your annual accounts in Word or PDF? Then you can't simply file them with the Dutch Chamber of Commerce (KvK). Most companies must submit their annual accounts digitally in XBRL or iXBRL.

Since financial year 2025 this also applies to large companies. But what exactly is iXBRL? And how do you convert existing annual accounts into the right format?

In short

• Since financial year 2025, large companies must also file digitally.
• You can use XBRL or iXBRL for this.
• In most cases a PDF is no longer sufficient.
• You can have existing annual accounts converted to iXBRL.
• Filing with the KvK is free. The conversion usually comes at a cost.

Is iXBRL filing mandatory?

Not always. The Dutch government requires companies to file their annual accounts digitally. This is done through Standard Business Reporting (SBR). The obligation was introduced in stages.

You usually have a choice between XBRL and iXBRL. Which format is suitable depends on the annual accounts. In certain situations you must use iXBRL, for example when you are required to submit a sustainability report.

More information is available on the website of the Chamber of Commerce (in Dutch).

What is the difference between XBRL and iXBRL?

XBRL and iXBRL are two ways of recording financial data digitally. Computers can read and process this data automatically.

iXBRL is especially useful for extensive annual accounts with many notes, tables and a custom layout.

Both formats are explained on the Standard Business Reporting website (in Dutch).

Can you file annual accounts as a PDF?

For most companies, no longer. For mandatory digital filing the KvK requires an XBRL or iXBRL file. Exceptions are only possible in special situations.

Do you already have the annual accounts in PDF or Word? Then you don't need to start over. The existing document can be used to create an iXBRL version.

The content of the annual accounts doesn't need to change for this. The document does need to be made technically suitable for the KvK.

How do you convert annual accounts to iXBRL?

Saving a PDF under a different file name is not enough. In an iXBRL conversion, financial data is given digital codes. This is also called tagging.

This allows a computer to recognise, for example, which amount is revenue, liabilities or equity.

The conversion consists of four steps:

The marking uses the rules that apply to your annual accounts.

What are the minimum requirements for tagging iXBRL annual accounts?

You don't have to tag everything in your annual accounts. The minimum requirements are set out in the SBR filing rules for the Business Register, the Regulatory Technical Standard (RTS). The 2026 version applies to financial years beginning on or after 1 January 2026. In short:

• Financial statements: tag all amounts in the balance sheet. If your accounts include them, also tag the amounts in the profit and loss account, the cash flow statement, the statement of comprehensive income and the statement of changes in equity. Under IFRS, this applies to the equivalent IFRS statements. Note: do your consolidated accounts refer to the separate (company-only) accounts for equity? Then only tag the statement of changes in equity in the separate accounts.

  

• Zero values: dashes, other characters and words that represent zero must be tagged too.
• Micro and small companies: do you only file an abridged balance sheet, possibly with notes? You may also use iXBRL.
• Mandatory filing data: KvK number, name, legal form, registered office, size class, balance sheet date and financial year. Also whether the accounts are consolidated, whether there is an auditor's report and whether the accounts have been adopted (and if so, the adoption date). Is this data not included in the annual accounts themselves? Then tag it in a separate iXBRL document for filing data. If you file the annual report of a foreign group parent for the exemption under Article 2:403 or 2:408 of the Dutch Civil Code (BW), one additional tag is required. Without these tags, the KvK will not process the annual accounts and you have not met your filing obligation.
• Notes and management report: you don't need to tag these yet. Block tagging of text will become mandatory later, but not until at least two years after the final European (ESMA) requirements. Until then, voluntary block tagging in the financial statements is not allowed.
• Auditor's report: if one is required, it is part of the report, in the same format as the annual accounts. You don't currently need to tag the data in the auditor's report.
• Currency and rounding: every amount gets a currency, such as EUR, and an indication of its rounding (the decimals attribute).
• Technical check: you submit everything as a single Report Package of no more than 100 MB. The KvK checks this package automatically. Afterwards, check in the Business Register that the filing has succeeded.

View the minimum tagging requirements in the SBR filing rules (Business Register 2026), page 12.

Filing an iXBRL file with the KvK yourself

Have you received the iXBRL file? Then you can file the annual accounts in two ways.

For the KvK portal, log in to Zelf Deponeren Jaarrekening (the KvK's portal for filing annual accounts yourself). After processing, you can check in the Business Register whether the annual accounts have been filed.

What does it cost to file annual accounts in iXBRL?

The KvK does not charge for filing annual accounts.

That doesn't mean the whole process is free. To create an iXBRL file you need suitable software. You can also have a specialised company do this for you.

The cost of the conversion differs per provider. The size and complexity of the annual accounts also play a role.

On the KvK website you can read more about filing through SBR and the possible costs.

When must you file the annual accounts?

Adopted annual accounts must be filed with the KvK within eight days.

In addition, there is a final deadline of twelve months after the end of the financial year. Have the annual accounts not yet been adopted? Then you may first need to file the unadopted version.

Also see the statutory filing deadlines at the KvK.

Frequently asked questions

Can I convert a PDF to iXBRL myself?

Yes, but you need special software for that. You don't just convert the file; you also need to give the financial data the right codes. The file must then meet the KvK's technical rules.

Is iXBRL also mandatory for a small private limited company (bv)?

No, not by default. A small bv must file its annual accounts digitally. That can be done, for example, through the KvK portal Zelf Deponeren Jaarrekening. You don't need to create an iXBRL file yourself for this.

Does the auditor's report also have to be in iXBRL?

If an auditor's report is required and you file the annual accounts in iXBRL, the auditor's report must be submitted in the same format. This is set out in the KvK filing rules.

Can I outsource the iXBRL conversion?

Yes. You can have the existing annual accounts converted by a specialised company. You then receive the iXBRL file you need for filing.

Need help converting to iXBRL?

Are your annual accounts ready, but is the iXBRL file missing? Then you can outsource the technical conversion.

Rapportagewijzer can do this for you. With iXBRL annual accounts we convert your existing annual accounts into a validated iXBRL file, and with Digipoort filing we can also submit it for you. For educational institutions there is OCW iXBRL reporting.