The provisional assessment: paying income tax in instalments
What a voorlopige aanslag is, why you pay monthly instalments, how to adjust it mid-year, and how it reconciles with your final income tax return.
If your income-tax bill last year was significant, the Dutch tax authority (Belastingdienst) will ask you to pay this year's estimate in monthly instalments. This is called a voorlopige aanslag — a provisional assessment. Instead of a single painful bill in May, you smooth your tax payments across 12 months. Here's how it works, why you might adjust it, and how it reconciles with your final return.
What is a voorlopige aanslag?
A voorlopige aanslag is the tax office's estimate of how much income tax you owe this year, based on last year's return. Rather than wait until May to bill you, they divide it into 12 equal monthly payments (or sometimes quarterly) and ask you to pay as you earn.
You'll receive a notice in the post (or digitally via Mijn Belastingdienst Zakelijk) stating:
- Your estimated tax for the year
- The monthly amount due
- The payment deadline (usually the 20th of each month)
It's a convenience for both you and the Belastingdienst: you don't face a surprise lump-sum demand in May, and the tax office gets steady monthly cash flow.
The voorlopige aanslag basics
Who gets a voorlopige aanslag?
Not everyone. The Belastingdienst only issues one if your tax bill last year exceeded a threshold (typically a few thousand euros). If you're just starting out and earned little, or if last year's bill was very small, you won't get a voorlopige aanslag — you'll simply pay everything when you file your return in May.
If you do get one and you disagree with the estimated amount, you can request an adjustment (verzoek om wijziging).
How the monthly payment is calculated
The voorlopige aanslag is based on last year's return. If last year you earned €40,000 profit and owed €8,000 in income tax (after deductions and credits), the Belastingdienst assumes you'll earn similar profit this year and bill you roughly €667/month.
But your actual profit this year might be higher or lower. If you spot a significant change mid-year, you can ask to adjust the voorlopige aanslag — lowering monthly payments if business is slow, raising them if it's booming. This prevents an unhappy surprise when you file.
Adjust early if you see a big change
If you invoiced 50% more than last year by June, request an increase to your voorlopige aanslag. Similarly, if contracts dried up and you're on track for half the profit, ask for a reduction. The longer you wait, the bigger the lump-sum adjustment in May.
The five-step monthly routine
- Receive the payment notice. You get a letter or a message in Mijn Belastingdienst with the monthly amount and due date.
- Transfer the money. Pay it like any other bill — by bank transfer or standing order.
- Record it. Note the payment in your administration (though the Belastingdienst tracks it).
- Keep track of your profit. If your actual earnings are on track to be very different from last year, consider requesting an adjustment.
- File your annual return. In May, when you file your final aangifte, the tax office reconciles what you've paid monthly against what you actually owe.
The May reconciliation
When you file your annual return in May, the Belastingdienst calculates your actual income tax based on your reported profit and deductions. They then subtract all the monthly voorlopige aanslag payments you made throughout the year.
Three outcomes:
- You paid exactly right: no extra bill, no refund.
- You paid too much: you get a refund (usually deposited into your account by June/July).
- You paid too little: you owe the balance, due when the final assessment is issued.
Most freelancers overpay slightly and enjoy a small refund in summer — often a bonus to spend or save.
Let ZZP Belasting do the maths
Automatic BTW returns, income-tax forecasts and depreciation — from the invoices you already have.
Try it freeAdjusting your voorlopige aanslag mid-year
You can request a change (verzoek om wijziging van de voorlopige aanslag) at any time using Mijn Belastingdienst Zakelijk. You'll need to:
- Estimate your profit for the full year (month-to-date actual plus projection)
- Calculate the implied tax
- Request the Belastingdienst adjust the monthly payments accordingly
Timing matters. If you request in January, the adjustment applies from that month forward. If you wait until November, you've already overpaid the whole year and will just get a big refund in May.
Don't ignore a voorlopige aanslag
If you receive a monthly payment notice and don't pay it by the deadline, interest and penalties accrue. Even if you think the estimate is wrong, pay on time and then challenge the amount — it's cheaper than late-payment penalties.
How it fits with BTW and cash flow
You're juggling three payments:
- Quarterly BTW (due end of month after the quarter): €1,000–€3,000+ each time
- Monthly voorlopige aanslag (income tax): €500–€1,000+ each month
- Health insurance and Zvw (ongoing): €200–€600+/month
Managing cash flow across these three streams is the main financial discipline for freelancers. Many set aside a percentage of each invoice (e.g., 30–35%) in a separate pot to cover tax and social contributions, so the bills don't surprise them. Read our guide to setting money aside for tax for a practical formula.
Frequently asked questions
What if I haven't paid my voorlopige aanslag by the deadline?
Can I stop paying a voorlopige aanslag once I get one?
Does the voorlopige aanslag count toward my final tax bill?
Is the voorlopige aanslag the same for every month?
A voorlopige aanslag is the tax office's way of spreading your bill evenly across the year instead of hitting you with a lump sum in May. It's predictable, adjustable, and counts fully toward your final bill. The key is to anticipate big changes in your profit early and request an adjustment — don't just hope and pay a surprise bill later. ZZP Belasting helps you track your profit forecast throughout the year so you know exactly when to adjust.