I never received an M-form. Should I file anyway?

You can. If you have not been asked to file, you may still file voluntarily up to five years back, for example to claim a refund of wage tax. A 2025 return can be filed until 31 December 2030.

Do I have to declare my foreign income on the M return?

For the part of the year you lived in the Netherlands, you report your worldwide income, including income a tax treaty assigns to another country, and claim relief for it in the return. For the part you lived abroad, you generally report only income from the Netherlands.

The M-form explained: your tax return for the year you move

Q: Can I file the M-form online?

Yes. Log in to Mijn Belastingdienst with a DigiD or a European login and choose the income tax return for people who lived outside the Netherlands for part of the year. The paper form M is still available if you cannot or do not want to file online.

The M-form (M-biljet, where M stands for migration) is the Dutch income tax return for the year you moved to or left the Netherlands. It splits that year into the part you lived here and the part you lived abroad, and taxes each part differently. You do not need the paper form. The Belastingdienst lets you file the M return online in Mijn Belastingdienst with a DigiD or a European login. If you worked here for only part of the year, filing it is often how you get wage tax back.

Who files an M return

You file an M return for a calendar year in which you immigrated to or emigrated from the Netherlands, so the year you arrived and the year you leave. The year after you arrive, if you live here all year, you file the ordinary return. Our guide to the 2027 tax return deadline covers that one.

Your arrival or departure date is normally the date you registered with, or deregistered from, the municipality. The form asks for it at the start.

Filing online or on paper

Online. Log in to Mijn Belastingdienst and choose Aangifte inkomstenbelasting voor belastingplichtigen die een deel van het jaar buiten Nederland wonen doen (income tax return for people who lived outside the Netherlands for part of the year), under Income tax, Tax return, Tax year. You need a DigiD. If you live abroad, you can apply for a DigiD from abroad or use a European login from your country of residence. The Belastingdienst's own notes point out that filing online means fewer mistakes, and it lets you file together with your tax partner.

On paper. If you cannot or do not want to file online, order the paper tax return form M for the right year from the Belastingdienst website. It is posted to you within two weeks. If you are self-employed and file on paper, you also have to fill in the M annual report, which you request from the Tax Information Line for Non-resident Tax Issues.

Deadline

When the Belastingdienst expects a return from you, it usually sends a letter inviting you to file. The date on that letter is your deadline. For the 2025 M return, the Belastingdienst said the online return would be ready in Mijn Belastingdienst from 1 May 2026, and that you could file until 1 July 2026.

If you cannot make the date, request a postponement before it. With a DigiD or European login you can do that yourself in Mijn Belastingdienst; otherwise call the tax information line.

If you did not receive an M-form or letter

Not getting a letter does not always mean you have nothing to file. You can check yourself whether you would pay or get money back. Log in and fill in the return, or order the paper form M.

If you have not been asked to file, you can still file voluntarily up to five years back. The Belastingdienst's table shows a return for 2025 must be in by 31 December 2030, and one for 2021 by 31 December 2026. That matters if you moved here in an earlier year and never claimed a refund.

What is different about the M return

The M return treats one calendar year as two periods:

	Period living in the Netherlands (binnenlandse periode)	Period living abroad (buitenlandse periode)
Your status	Resident taxpayer	Non-resident taxpayer, or not taxable here at all
Income you report	Your worldwide income	Only income from the Netherlands, such as Dutch wages or a Dutch property
Tax credits and deductions	As a resident	Only if you meet the conditions for qualifying non-resident taxpayers

A few things follow from this:

Tax credits are time-apportioned. The form asks exactly when you lived in the Netherlands, so the Belastingdienst can work out whether you get the full tax credits or a pro rata share.
Foreign income is reported, but not necessarily taxed twice. As a resident you report your worldwide income, including income that a tax treaty says is taxed in another country. You then claim relief for it in the return. The Belastingdienst's immigration checklist puts it this way: foreign income is not automatically taxed in the Netherlands.
Your worldwide income for the whole year is asked for. This is used, among other things, to check whether you qualify for the non-resident deductions and credits for the foreign part of the year.
Foreign currency. Convert amounts at the bank rate on the date you received or paid them, not the rate on the day you fill in the return. The Belastingdienst refers you to the European Central Bank for rates.

If your family stayed behind while you worked here, or the other way round, working out where you actually lived for tax purposes can be complicated. The Belastingdienst advises contacting it in that case, and requesting a postponement while you sort it out.

Refunds of wage tax

Your employer withholds loonheffing (wage tax) from every payslip. Among its examples of when you may get money back, the Belastingdienst lists: "you lived in the Netherlands for only part of the year and received wages or a benefit." The general reason for a refund is the same as for anyone else: tax credits or deductions that were not yet taken into account during the year.

If you have the 30% ruling, you do not calculate it yourself. The salary on your jaaropgaaf (annual statement) already reflects it, so you enter that figure, including in a year in which the ruling ended.

To receive a refund, the Belastingdienst needs your bank account number. New arrivals can send it with the form Opgaaf rekeningnummer particulieren, which is only available in Dutch.

After you file

The Belastingdienst says you will usually hear within three months. That might be a letter confirming it has your return, or a provisional assessment. It has three years to issue the final assessment: for 2025, by 31 December 2028 at the latest, plus any postponement you had. In practice it is usually quicker.

While you have the figures to hand, check your provisional assessment for the current year, if you have one, and adjust it if it is too low or the refund too high. That way you avoid paying back money, and possibly tax interest, later.

Where to go from here

The M return gets complicated quickly with foreign income, a partner who arrived later, or the 30% ruling. If you would like someone to prepare or check it in English, you can request tax advice and up to three advisers will contact you. If you are leaving rather than arriving, read leaving the Netherlands and your taxes.

Sources

Figures checked against the sources above on 23 September 2026.

Photo: Erik Wannee, Wikimedia Commons, CC0.