Can I program an XBRL file myself?

The short answer

Yes. You must apply the right taxonomy and submission rules. A valid XML file is not yet substantively correct or accepted annual accounts.

Basis: art. 2:362 and 2:394 DCC; SBR domain Business Register (Handelsregister)

Which taxonomy applies to your financial year?

Programming an XBRL file yourself is technically possible, but it takes more than putting amounts between XML tags. You must use the right report type, taxonomy version and contexts. First determine for which entity, size class and reporting period you are reporting. For a one-off micro or small single-entity publication, the KVK portal may be more practical.

Start with the current documentation of the SBR domain Business Register. The permitted format and the associated rules depend on the report and the financial year. Do not simply copy a file from another company. It may contain a wrong entry point, incorrect entity data or periods that do not fit. In XBRL, a context describes, among other things, which company and period a fact relates to. A balance sheet item needs a reporting date; a result item usually a period. Unit, precision and the meaning of missing values must also be right. Merely changing a file name does not resolve these differences.

How do you validate self-made XBRL?

Make the financial content verifiable independently of the export. Record a mapping from your reporting items to the concepts used and keep the source amounts available. Test totals, signs and comparative periods with a small file whose correct outcome you know. A negative amount may indicate a loss in one presentation and lead to a wrong classification in another context. Art. 2:362 DCC remains applicable to the view the annual accounts give. The technical standard determines how information is delivered; it does not replace the assessment of whether an item is correctly valued.

Validate against the applicable taxonomy and the additional submission rules before you submit. Keep the validation report, the exact export and the version of your code used. A validator can find missing fields or invalid combinations, but does not know all the facts of your company. So also check a readable rendering against the adopted report. iXBRL has different technical requirements than an ordinary XBRL instance; do not treat those formats as interchangeable extensions. The official SBR documentation for the financial year in question describes the available taxonomies and examples. Use it as the starting point for your implementation.

How do you submit the file?

Arrange the submission route separately. A file on your computer is not yet filing, and an attempt to send is not yet proof of acceptance. Check the status after submission and keep the receipt. Ask an intermediary in advance whether it is willing to process your self-made file and which checks it must meet. The costs of development, maintenance and error investigation can be greater for one BV than the saving on reporting software. Programming it yourself suits someone who can maintain the standards on a structural basis. For occasional annual work, a supported official route is usually easier to organise and to check.

Sources

• SBR: Business Register documentation, financial year 2025
• KVK: preparing and filing XBRL annual accounts

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