In this guide
For many employees the Dutch tax system is a once-a-year event: the annual return in spring. Homeowners and people with freelance income on the side tend to meet it twelve times a year instead — because they have a voorlopige aanslag, and their tax position is settled monthly rather than annually.
That difference is worth real money in cash-flow terms, and autumn is a good moment to think about it: for 2026 the form was available from 1 December 2025. Request early and the payments are spread over the whole year; without one, a refund only arrives after you file the annual return the following year.
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💡 Related: how to request a Dutch tax filing extension, how to get a mortgage as an expat, tax filing for freelancers and ZZP.
What it is, mechanically
The Dutch income tax year is settled in arrears: you earn in 2026, file in spring 2027, and receive or pay the difference some months later. A provisional assessment short-circuits that lag by estimating the outcome in advance and settling it as you go. It runs in two directions.
Money coming to you. The classic case is hypotheekrenteaftrek — mortgage interest relief. If you own the home you live in, the interest is deductible and the deduction usually produces a refund. Rather than waiting until the following year, you can have the estimated refund paid monthly. For many homeowners this is a sizeable yearly amount.
Money going out. If you have income that is not taxed at source — freelance profit, box 3 income above the tax-free allowance — you can pay the estimated tax monthly instead of facing one large assessment later. It is not a discount but a smoothing mechanism, and it removes the classic freelancer trap of spending money that was always going to be tax.
The annual return remains the final word: whatever the assessment got wrong is corrected there.
Who should have one
Four groups benefit most clearly:
Homeowners. If you bought this year, you are probably owed money and may not have set anything up. Ask your mortgage adviser whether they requested it for you; if not, request it yourself. If you are still working out whether buying is realistic, the expat mortgage guide, the how much can you borrow breakdown and the best mortgage broker for expats comparison cover the decision.
Freelancers and ZZP’ers. A quarterly VAT rhythm plus an annual income tax bill is the worst of both worlds for cash flow. A provisional assessment gives income tax the same monthly shape as everything else you pay — see tax filing for freelance expats.
People with substantial box 3 assets. Above the tax-free allowance, the box 3 charge is predictable enough to pay monthly. What it is based on, and what changes in the years ahead, is in box 3 in 2027.
Anyone whose income changed sharply mid-year. Payroll withholding assumes a stable year, and a stable year is exactly what a move to the Netherlands is not.
If none of those apply — one Dutch employer, rented flat, no side income — you almost certainly do not need one.
How to request or change one
Requesting. Log in to Mijn Belastingdienst with your DigiD and open the Voorlopige aanslag form for the relevant year. You enter estimates: expected salary, mortgage interest paid, WOZ value for the eigenwoningforfait, expected profit if self-employed, assets on 1 January for box 3, and your fiscal partner’s details.
Timing. The Belastingdienst made the 2026 form available from 1 December 2025. Request one later in the year and the annual amount is simply spread over fewer months, so the instalments are bigger.
When money moves. The first payment comes about eight weeks after the request, with later payments usually on the 15th of the month. Plan around that lag rather than expecting a December request to produce January money.
Changing. The same form changes an existing assessment. Do it when reality diverges from the estimate: you overpaid or refinanced the mortgage, sold the property, your partner started or stopped working, or your income changed materially.
Stopping. Changing is usually better than stopping. If you sell the house, change the assessment so the refund reflects the months you still owned it. Stopping is only possible for an assessment that pays out to you; for 2026 it was possible until 1 October 2026, and for deductions it applies retroactively from 1 January 2026, so you repay what you received this year (Belastingdienst, checked 29 September 2026).
The expat-specific complications
The 30% ruling changes the income figures. The expat ruling lowers your taxable salary. Because mortgage interest is deductible at no more than 37.56% in 2026, that usually does not change the rate at which the interest is deducted, unless the ruling brings your taxable income into the first bracket (up to €38,883), where the rate is 35.75%. When the ruling starts, ends or steps down, the assumptions in your assessment go stale immediately. What changes from 2027 is in the 30% ruling in 2027.
Fiscal partnership is not the same as being married abroad. Whether you count as fiscal partners under Dutch rules determines how deductions are split, and getting it wrong leads to a correction later — see finances for international couples.
Migration years break the estimate. In the year you arrive or leave, part of the year sits outside Dutch residence, so an estimate built on a full Dutch year will be wrong — a case where an adviser for the first assessment can be worth it.
Automatic continuation is a trap as well as a convenience. The Belastingdienst rolls last year’s assessment forward and sends it around mid-December. Do nothing and it keeps paying — or collecting — on the old assumptions all year.
A worked illustration (model calculation, not advice)
The figures below are invented for illustration and are not a prediction of your own outcome.
Suppose a household pays €9,000 in deductible mortgage interest and the eigenwoningforfait adds €2,200 back to taxable income, so the net deduction is €6,800. In 2026 mortgage interest is deductible at no more than 37.56%, even for income in the top bracket (Belastingdienst, checked 29 September 2026). At that rate the modelled annual benefit is about €2,554, roughly €213 a month.
That is what a provisional assessment does: it converts an abstract annual entitlement into a predictable monthly line in your bank statement. Your actual rate depends on your income, bracket and whether the expat ruling applies; the rules behind the deduction itself are in mortgage interest deduction for expats. The salary after tax calculator is the quickest way to sanity-check the income you enter.
My final thoughts
The voorlopige aanslag is easy to miss if nobody points you to it. Homeowners who do not request one wait for the annual return to get a refund they could have received monthly.
What makes it work is simple. Request or review it when the form for the new year opens (for 2026, on 1 December 2025). Change it the same month your circumstances change, not the following spring. And if you own property, hold significant assets or have income the payroll never sees, treat it as part of your standard financial setup here — alongside the annual return itself, covered step by step in how to file Dutch taxes as an expat.
Verified against Belastingdienst guidance on 20 August 2026 and rechecked on 24 September 2026: voorlopige aanslag overview and from when you can request or change one.
Frequently Asked Questions
What is a voorlopige aanslag in plain English?
It is a provisional tax assessment: an estimate of your tax position for the current year, settled in monthly instalments rather than in one lump sum after the annual return. If the estimate says you are owed money — typically because of mortgage interest relief — the Belastingdienst pays you monthly. If it says you owe money, usually because of freelance or investment income, you pay monthly. The annual return later settles the difference either way.
When can I request or change a voorlopige aanslag for next year?
For 2026, the Belastingdienst stated that the Voorlopige aanslag 2026 form was available from 1 December 2025. If you already had a provisional assessment for the previous year, the Belastingdienst continues it automatically and sends you the new assessment around mid-December, which is your cue to check whether the figures still match your situation.
When do the monthly payments actually start?
The Belastingdienst states that the first payment follows roughly eight weeks after your request, and subsequent payments usually arrive on the 15th of the month. The annual amount is divided into equal monthly instalments over the remaining months of the year, so a request made mid-year produces larger monthly amounts than a request made in December.
Do I have to request one every year?
No. Once you have a provisional assessment, the Belastingdienst continues it into the following year automatically. That convenience is also the risk: it keeps paying out on last year's assumptions, so if your mortgage, income, or partner situation changed, you have to change the assessment yourself.
What happens if my estimate was too high?
You repay the difference after the annual return. That is not a penalty, but it can be an unwelcome bill a year later, and interest may apply. This is why a provisional assessment is something to review whenever your circumstances change — after a pay rise, a mortgage overpayment, a change in ownership share, or an end to the expat ruling — rather than a set-and-forget arrangement.
Can an expat with the 30% ruling have a voorlopige aanslag?
Yes, and the interaction is worth getting right. In 2026 mortgage interest is deductible at no more than 37.56%, so the ruling usually does not change the rate at which it is deducted, unless it brings your taxable income into the first bracket (up to €38,883), where the rate is 35.75%. What the ruling does change is your income figures. If your ruling starts, ends, or drops to a lower percentage during a year, the assumptions behind an existing provisional assessment stop being accurate — check it in the same month the payroll change happens rather than the following spring.