◆ Expat tax guide
The M-form explained: your Dutch tax return in the year you move
Moved to the Netherlands, or left, during the year? Then you file a special tax return: the M-form. What it is, when to file it and why it often leads to a refund.
Updated October 2026
In short
- The M-form is the Dutch tax return for the year you immigrated or emigrated.
- It covers the part of the year you lived in the Netherlands and the part you did not.
- For tax year 2025 it could be filed from 1 May to 1 July 2026, later than the regular return.
- We file it for you with professional tax software and an official authorisation (machtiging).
- Because wage tax is withheld at full-year rates, the M-form often leads to a refund.
What is the M-form?
The M-form (aangifte M, M for migratie) is the income tax return for people who lived in the Netherlands for only part of the year because they moved here or moved away. Instead of two separate returns, one form covers the whole year.
Who needs to file it?
You file the M-form for the year in which you:
- moved to the Netherlands (immigration), or
- left the Netherlands (emigration).
In the years after (or before), you simply file the regular return, if you need to file at all. See Do I need to file a Dutch tax return?
What does it cover?
The form splits the year in two:
- The period you lived in the Netherlands. You are a Dutch resident taxpayer for this period: in principle your worldwide income counts, with tax treaties preventing double taxation.
- The period you lived abroad. Only certain Dutch income is relevant, such as salary for work done in the Netherlands or Dutch real estate.
The date you registered or deregistered with your municipality usually marks the split.
Why the M-form often leads to a refund
Your employer withholds wage tax as if you earn your salary for the whole year. If you only worked here part of the year, too much tax has often been withheld. Tax credits for the period you lived here are also settled through the M-form. Many expats therefore get money back. That said, foreign income or assets can work the other way, so it depends on your situation.
When can you file it?
The M-form becomes available later than the regular return. For tax year 2025, migrants could file from 1 May to 1 July 2026. You can file it online in Mijn Belastingdienst or on the paper M-form. When we file it for you, we use professional tax software and an official authorisation (machtiging) from the Belastingdienst: you receive a code by post and pass it on to us. We do not work with your DigiD.
After filing you usually hear within about three months: either a confirmation of receipt or a provisional assessment. The Belastingdienst has three years to issue the final assessment; for tax year 2025 that is by 31 December 2028.
Important: your DigiD is always personal
Is someone asking for your DigiD login? Never give it. Not to a tax advisor, a relative or someone who says they are from the Belastingdienst. A trustworthy advisor works with an authorisation (machtiging) and never needs your DigiD.
What you need
- Your exact date of arrival or departure (as registered with the municipality)
- Annual income statements (jaaropgaaf) from your Dutch employer
- Details of income earned abroad in the same year
- Bank, savings and investment balances
- Mortgage details, if you bought a home
- Your 30% ruling decision, if applicable
How we help
The M-form is more complex than the regular return, and it is in Dutch. We prepare and file it for you in English, make sure both periods are handled correctly and claim the credits you are entitled to. The M-form is included in our expat income tax return: €375 incl. VAT per tax year. See our pricing.
Frequently asked questions
What is the M-form in the Netherlands?
The M-form is the Dutch income tax return for the year in which you moved to or left the Netherlands. It covers both the period you lived in the Netherlands and the period you lived abroad.
When can I file the M-form?
The M-form becomes available later than the regular return. For tax year 2025, it could be filed from 1 May to 1 July 2026.
Can I file the M-form online?
Yes. You can file it online in Mijn Belastingdienst, or request the paper M-form from the Belastingdienst. If Den Boer Fiscale Dienstverlening files it for you, we use professional tax software and an official authorisation (machtiging), not your DigiD.
Do I have to declare my foreign income on the M-form?
For the period you lived in the Netherlands, your worldwide income is in principle relevant, with tax treaties preventing double taxation. For the period you lived abroad, only certain Dutch income counts.
Will I get a refund with the M-form?
Often, yes. Wage tax is withheld as if you work in the Netherlands all year, so if you arrived or left mid-year too much tax has frequently been withheld. Foreign income or assets can change the outcome, so it depends on your situation.
Do I need to give my DigiD to my tax advisor for the M-form?
No, never. Your DigiD is always personal, so never give it to anyone who asks for it. We file your M-form with professional tax software and an official authorisation (machtiging) from the Belastingdienst.
Questions about your own situation?
Book a free introductory call. We will tell you what applies to you and what it costs, before you commit to anything.