Dutch Tax Return Explained: 1 May Deadline, M Form for Newcomers and How Refunds Work

Last updated: October 2, 2026

THE HAGUE – October 1, 2026 | The Dutch Daily

Dutch tax return: most people in the Netherlands file their income tax return (aangifte inkomstenbelasting) in spring, for the previous year. The usual deadline is 1 May, and you can ask for an extension until 1 September. If you file before 1 April, the Belastingdienst lets you know before 1 July whether you get money back or have to pay. In the year you move to the Netherlands you usually file a special return: the M form. Here is how it all works.

1. Do you need to file a tax return?

In the Netherlands your employer withholds payroll tax (loonheffing) from your salary every month. For many employees that is close to the right amount, but filing a return can still be required or worthwhile:

• You must file if you received an invitation letter (aangiftebrief) from the Belastingdienst, or if you know you have to pay more than a small amount.
• It is often worthwhile if you can claim deductions, for example mortgage interest, or if your employer withheld too much tax because you did not work the whole year.
• You must file an M form for the year in which you moved to (or away from) the Netherlands, if you receive one or want a refund.

If you did not receive a letter but must file, the Belastingdienst says you must do so before 14 July following the tax year.

2. Deadlines: 1 May and the 1 September extension

Your return must reach the Belastingdienst before the date in your invitation letter, which is often 1 May.

• Need more time? Request an extension (uitstel) before 1 May through Mijn Belastingdienst. You then have until 1 September.
• Using a tax adviser? Advisers often have a longer, separate extension scheme for their clients.
• Late or missing return? The Belastingdienst can send a reminder and a demand, and impose a fine if you still do not file. It can also estimate your tax.

3. File before 1 April, hear before 1 July

If you file your return before 1 April, the Belastingdienst will let you know before 1 July whether you have to pay or will receive money. Usually you first receive a provisional assessment (voorlopige aanslag), followed later by the final assessment (definitieve aanslag).

So if you expect a refund, filing early pays off: you get your money sooner.

4. The M form: your first (or last) year in the Netherlands

In the year you move to the Netherlands, you lived abroad for part of the year. For that year you file a special return, the M form (migration form), for taxpayers living outside the Netherlands for part of the year.

• Online: log in to Mijn Belastingdienst and choose the income tax return for people who lived outside the Netherlands for part of the year.
• On paper: you can request a paper M form via the Belastingdienst forms page.
• Deadline: the M form has its own timing. For the 2025 tax year, the online M return became available from 1 May and could be filed until 1 July 2026. Check the date that applies to you in Mijn Belastingdienst or in your letter.
• Processing: you usually hear within 3 months after filing; the Belastingdienst has 3 years to process the return.

The M form is more complex than a normal return because it covers income in both countries. Many newcomers on the 30% ruling use a tax adviser for their first year. Our first 30 days checklist mentions the M form so you do not forget it.

5. How filing works: the pre-filled return

1. Log in to Mijn Belastingdienst with your DigiD (see our DigiD guide).
2. Check the pre-filled data (vooraf ingevulde aangifte): the Belastingdienst already has data from your employer, bank and mortgage lender. Always check it; you remain responsible for what you submit.
3. Add what is missing, such as deductions, foreign income or assets abroad.
4. Box 3: declare savings and investments above the tax-free allowance. Our article on Netherlands changes 2027 covers the box 3 plans.
5. Submit and keep a copy (PDF) of your return.

6. Provisional assessment: getting your refund monthly

If you know in advance that you will get money back, for example because of mortgage interest, you can request a provisional assessment (voorlopige aanslag) for the current year. You then receive the refund in monthly instalments instead of once a year. It also works the other way: if you know you will have to pay extra, you can pay in instalments to avoid a large bill.

Once you have filed the return for a year, you can no longer request or change a provisional assessment for that year.

7. Tax returns and allowances

Your tax return also determines the final amount of your allowances (toeslagen), such as zorgtoeslag and kinderopvangtoeslag, because they depend on your income. If you have an extension for your tax return, you may also have more time to apply for allowances for that year. See our guides to zorgtoeslag and childcare allowance.

8. Tips to avoid problems

• Keep your annual statements (jaaropgaaf) from your employer and bank.
• Declare foreign bank accounts and property; the Netherlands exchanges data with many countries.
• Be careful with phishing: the Belastingdienst never asks for your DigiD password by email or text message.
• If you made a mistake, you can correct it after filing.
• Moving away from the Netherlands? You usually file an M form again for the year you leave, so keep your Dutch DigiD and records.
• Not sure? The Belastingdienst has a helpline (BelastingTelefoon), and many municipalities and libraries offer free help with simple returns.

9. Common deductions to check

Deductions (aftrekposten) can lower the tax you pay. Some that internationals often encounter:

• Mortgage interest (hypotheekrenteaftrek) on your own home, under conditions.
• Gifts to registered charities (ANBI’s), above a threshold.
• Specific healthcare costs (specifieke zorgkosten) that insurance does not cover, under strict conditions.
• Partner alimony paid to an ex-partner.

Each deduction has its own conditions and thresholds. The pre-filled return does not include everything automatically, so check what applies to you.

10. Fiscal partners

If you are married, in a registered partnership, or meet certain other conditions, you are fiscal partners (fiscaal partners). Fiscal partners can divide certain income and deductions between them, such as box 3 assets and mortgage interest, which can lower the total tax. You can each file your own return or file together.

11. Key takeaways

• The usual deadline is 1 May; request an extension in time and you have until 1 September.
• File before 1 April and you hear before 1 July.
• In your arrival year you usually file an M form.
• Check the pre-filled return carefully: you are responsible for what you submit.
• Your income on the return also determines the final amount of your allowances.

12. FAQ

When is the Dutch tax return deadline?

The date in your invitation letter, often 1 May. With an extension requested in time, you have until 1 September.

What is the M form?

The tax return for the year you moved to or from the Netherlands, when you lived abroad for part of the year.

When do I get my tax refund?

If you file before 1 April, you hear before 1 July, usually through a provisional assessment.

Do I need DigiD to file?

Yes, for filing online via Mijn Belastingdienst.

🇳🇱 Dutch Corner

Sources

• Belastingdienst: wanneer moet mijn aangifte inkomstenbelasting binnen zijn (date in your letter, often 1 May).
• Belastingdienst: uitstel aanvragen (request before 1 May, extension until 1 September).
• Belastingdienst: wanneer hoor ik iets (filed before 1 April: decision before 1 July; usually provisional assessment first).
• Belastingdienst: filing a tax return for the year of emigration or immigration (M form online or on paper; usually informed within 3 months; 3 years to process).
• Belastingdienst: tot wanneer kan ik een voorlopige aanslag aanvragen of wijzigen; no letter received: file before 14 July.
• Belastingdienst: filing from 1 March with the pre-filled return in Mijn Belastingdienst.

More in our guide: Taxes, Salary & Money in the Netherlands

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