A Dutch tax assessment is a formal government decision. If you disagree with it, do not rely only on telephone calls: check the assessment, correction options and formal objection deadline.
Provisional assessment (voorlopige aanslag)
A provisional assessment can spread an expected tax payment or refund across the year. It is based on estimated information and can often be changed when your circumstances change. It is not the final reconciliation for the year.
Final assessment
After your return is processed, Belastingdienst can issue an assessment showing the tax due or refundable. Compare it with the submitted return and supporting documents.
If you disagree
- Read the assessment and legal-remedies section.
- Check whether the issue can be corrected through the return/online route.
- If a formal bezwaar is needed, respect the deadline shown on the assessment.
- Explain which part is wrong, why, and attach evidence.
- Keep proof of submission.
- If the dispute is financially significant or cross-border, consider professional tax advice or legal help.
Tax and toeslagen are different systems
A tax assessment and a toeslag decision are separate. Changing your estimated income for one purpose does not always fix the other automatically. Keep Mijn Belastingdienst and Mijn Toeslagen both up to date where applicable.