The voorlopige aanslag explained: what it is, who it applies to, and what you can do with it

Each year, many of our clients receive a letter from the Belastingdienst requesting a tax payment - or offering a monthly refund - before they have filed anything at all. This letter relates to the voorlopige aanslag, or preliminary tax assessment. It is one of the more misunderstood parts of the Dutch tax system, and in our experience, a little clarity goes a long way.

What is a voorlopige aanslag?

A voorlopige aanslag is the Belastingdienst's estimate of your tax position for the current year, issued before your annual return is filed. It is based on your income from previous years and results in either monthly payments to the tax authority or monthly refunds to your account, depending on whether you are expected to owe tax or be entitled to a refund.

It is not a final assessment. Once your actual return is filed and processed, the Belastingdienst issues a definitive aanslag which reconciles any difference between the preliminary estimate and the real figures.

Who does it apply to?

Not everyone receives a voorlopige aanslag. Employees whose loonheffing (payroll tax) is withheld correctly by their employer are often fully covered and will not receive one. It is more commonly relevant for:

• ZZP'ers and freelancers whose income is not subject to payroll withholding

• VOF partners drawing profit from the business

• DGAs who receive dividends from their BV

• Homeowners entitled to mortgage interest deduction (hypotheekrenteaftrek)

• Individuals with significant Box 3 assets such as savings or investments

• People who arrived in or departed from the Netherlands during the tax year

It works in both directions

This is something many people are not aware of. The voorlopige aanslag does not only result in payments to the Belastingdienst - it can equally result in the Belastingdienst paying you.

If your tax calculation shows that you are entitled to a refund -for example, because of deductible mortgage interest, other allowable costs, or because too much loonheffing was withheld — you can request a proactive voorlopige aanslag and receive that refund spread across the year in monthly instalments, rather than waiting until after you file your return.

This is particularly relevant for homeowners. Mortgage interest is deductible against income tax, but employers do not factor it into payroll calculations. Many homeowners are therefore entitled to a meaningful annual refund and do not realise it can be received monthly. Requesting a proactive voorlopige aanslag converts that entitlement into regular monthly payments, which can make a material difference to cash flow.

One important caveat: the monthly refund is based on an estimate. If the estimate is set too high because other income sources, Box 3 assets, or employment benefits were not factored in, a portion may need to be repaid when the definitive assessment is issued. It is worth having an adviser review the full picture before submitting, to ensure the figures are realistic.

Why did the Belastingdienst refund money I had already paid?

This is a situation we encounter regularly and it causes understandable confusion. The voorlopige aanslag is structured as monthly instalments across the year. If the full assessed amount is paid in a single lump sum rather than month by month, the Belastingdienst refunds the portion that relates to future instalments not yet due, and issues a revised assessment showing the reduced outstanding balance.

The total liability has not changed. The schedule has simply been reset. This is not an error on either side- it is how the instalment system is designed to work.

Note: If you receive an unexpected amount back from the Belastingdienst, we would recommend checking what it relates to before treating it as a windfall. In many cases, it is a repayment of future instalments, not a final refund.

Can you adjust or cancel it?

Yes. The voorlopige aanslag can be amended via MijnBelastingdienst. If your income this year is expected to be lower than the previous year on which the assessment is based, it makes sense to request a reduction rather than continuing to pay on outdated figures.

It is also possible to reduce the assessment to zero. For clients who prefer to manage their own tax reserves, this can be a sensible approach, provided the annual return is filed, and any tax due is paid before 1 May of the following year. If that deadline is met, the Belastingdienst does not charge belastingrente (tax interest) on the amount owed. The money remains in your account in the interim, available to you and earning interest.

For self-employed clients, we often recommend this approach combined with a disciplined monthly saving habit - setting aside a fixed percentage of income each month into a dedicated account, so the funds are available when the return is filed, and the bill arrives.

Worth noting: reducing the voorlopige aanslag to zero only works cleanly if the return is filed on time. If it is not, belastingrente is charged at 7.5% on the outstanding amount from 1 July of the tax year. For clients we work with, late filing is not a concern — but it is important to understand the condition.

What about BV owners?

If you operate through a BV and pay yourself a DGA salary, loonheffing is withheld at source and that portion of your income tax is covered. However, if you also distribute dividends, the 15% withholding tax applied at source is generally lower than your actual income tax rate on that income, meaning additional tax is typically due. Box 3 wealth adds further to the picture. For clients with BVs, we review the voorlopige aanslag position as part of our standard annual accounts process to ensure nothing is overlooked.

The voorlopige aanslag is a practical mechanism for managing tax across the year, in either direction. Understanding how it works and knowing that it can be adjusted, cancelled, or proactively requested - puts you in a much stronger position to manage your cash flow and avoid surprises at year-end.

If you have received a letter you are uncertain about, or would like to discuss whether requesting or adjusting a voorlopige aanslag makes sense for your situation, we are happy to advise.

Get in touch

We work with freelancers, expat founders, and small businesses across the Netherlands on tax compliance, annual filings, and ongoing financial advice. If you have questions about your voorlopige aanslag or your broader tax position, please reach out.