Objecting to a tax assessment: deadline, structure and deferral
Written by Ilias Aarrass6 min read · Published on · Last reviewed on 
In short
You have six weeks from the date on the assessment to object; for the amount you dispute you are granted deferral of payment, but collection interest keeps running.
- The tax authority normally decides within twelve weeks of the date on the assessment, with an extension of at most six weeks.
- An objection must state the date, your name and address, the assessment number, the reason for your objection and your signature.
- The part of the assessment you do not dispute must simply be paid on time.
- If you are late, the inspector usually still treats your objection as a request for an ex officio reduction, up to five years after the tax year ends.
An assessment that is wrong, a penalty you consider unjust or a correction you do not recognise: it happens to nearly every entrepreneur at some point. The reflex is to call, but the only step that safeguards your rights is a written objection within the deadline. That is less work than it sounds, and it costs nothing. In this article: which deadline applies, what an objection that gets taken seriously looks like, why you separately request deferral of payment, and which routes remain once the deadline has passed.
Six weeks from the date on the letter, not from receipt
The objection period is six weeks and starts on the date printed on the assessment, not the day you opened the letter. If post sits on your doormat for two weeks while you are away, a third of your window is gone. Your objection must be received within those six weeks, not merely sent; filing digitally through the business portal is therefore safer than post. You can object to nearly anything you receive on paper: a final income tax assessment, an additional income tax or VAT assessment, a default or deliberate-error penalty and an interest decision.
A provisional assessment is an exception for which you usually need no objection at all: you simply adjust it yourself in your provisional assessment. A return that has not yet been finalised can likewise just be filed again; the latest version counts.
What belongs in an objection
An objection need not sound legal. It must be complete and refer to the right assessment. Keep it short and factual: what you object to, why you consider it wrong, what you think should happen instead and which evidence you enclose. That last point is decisive: an objection without substantiation is nearly always rejected, even when you are right.
- Your name, address, citizen service or tax number, and the assessment number with its date.
- One sentence stating that you object and exactly what against.
- The facts in chronological order, without indignation.
- The amount or correction you consider correct, with a calculation.
- Attachments: invoices, bank statements, contracts, your hour records or correspondence.
- A request to be heard if your objection is rejected, and the amount for which you want deferral of payment.
The hearing
Before an objection is rejected in whole or in part, you have the right to a hearing. Ask for it in your objection straight away. It is not a formality: in that conversation you see the file, hear where the inspector believes it fails and can still add documents. Many disputes end there, without any procedure being needed.
Objecting and paying: how the two interact
For the part of the assessment you object to, you are granted deferral of payment, so name that amount clearly in your objection. The part you do not dispute must simply be paid on time. Do watch the interest: even with deferral, collection interest keeps running for as long as the assessment is not paid in full before its final payment date. If you are proved right later that interest is reversed; if not, you still pay it. If it genuinely will not work, see unable to pay your tax bill for a payment arrangement.
The tax authorities in principle decide within twelve weeks, with options to extend. If you are right, the assessment is reduced and a refund follows with interest. If not, you can appeal to the district court within six weeks of the decision. That involves court fees, so weigh the amount against the effort; for larger corrections engaging a tax specialist is nearly always sensible.
Missed the deadline? There is still a route
If you are late, your objection is declared inadmissible, but the inspector usually still assesses it as a request for an ex officio reduction. That is possible up to five years after the end of the tax year, provided there is a demonstrable error to your disadvantage. The difference with a timely objection matters: only limited legal recourse exists against a refused ex officio reduction, so you lose part of your options. With an audit or a series of corrections across years, meeting the six weeks genuinely pays.
If you cannot meet the deadline because documents are missing, file a pro forma objection: one paragraph stating that you object and asking for time to supplement it. That is valid and keeps your case open. Do make sure the supplement actually arrives within the period granted.
The deadlines at a glance
Objecting is mostly a matter of dates. These are the deadlines that count, all measured from the date printed on the letter and not from the day you opened it.
| Step | Deadline | What to watch |
|---|---|---|
| File an objection | 6 weeks from the date on the notice | Must have been received, not just sent |
| Decision by the tax authorities | 12 weeks, extendable to 18 | You are entitled to a hearing before a rejection |
| Appeal to the court | 6 weeks after the decision | Court fees apply; weigh them against the amount |
| Ex officio reduction | Up to 5 years after the tax year | Only for a demonstrable error in your disadvantage |
| Deferral of payment | Runs alongside the objection | State the amount explicitly; collection interest keeps running |
Frequently asked questions
Does objecting cost money?
No, the objection procedure is free. Only when you appeal to the court afterwards do you pay court fees. Adviser costs may be partly reimbursed if your objection succeeds, but only if you request that within your objection.
Can I object to a default penalty?
Yes, within the same six weeks. Your chances are best with force majeure or an unjust imposition, for instance when you demonstrably paid on time but with a wrong payment reference. After a first slip following years of clean filing, penalties are regularly reduced. See also filing VAT late.
I agree with the assessment but cannot pay. Does objecting help?
No, and it can work against you: a groundless objection is rejected while collection continues. In that case request a payment arrangement straight away, which is a separate procedure with its own conditions.
What if the assessment is right but my own return was wrong?
Then correct yourself. If the assessment is not yet final, file the return again. If it is and you overpaid, request an ex officio reduction. For VAT, use the correction return; reporting it yourself is nearly always cheaper than waiting.
Sources
- Objection and deferral of paymentBelastingdienst · belastingdienst.nl
- When will I hear about my objection?Belastingdienst · belastingdienst.nl
- How do I file an objection?Belastingdienst · belastingdienst.nl
Sources checked on
This article provides general information based on the rules known for 2026 and does not replace personal tax advice. For your specific situation, we're happy to take a look with you.
