Just Moved to the Netherlands? Your First Tax Return Is Different
If you arrived in the Netherlands last year, your first Dutch tax return is not a normal one. In your first year you have to file an M-form instead of the standard online aangifte. This is a special migration tax form that covers your partial year as a Dutch resident. This M Form is the single most common reason expats end up with a tax advisor in their first year. Below you’ll see what your tax bill looks like and what makes the M-form harder than a regular return.
Quick answer
The M-form (M-biljet) is the special tax return you file in the year you arrived in, or left, the Netherlands. Because you were a Dutch tax resident for only part of the year, the calculation has to split your income, deductions, and credits between the resident and non-resident periods. There is a digital version now, but the form is much longer and more detailed than the standard online aangifte.
One wrong answer can cost you hundreds in extra tax or missed credits. Most expats either spend a full weekend wrestling with it, get it wrong, or hand it off to an expat tax advisor. Your options: wait for the form to arrive in your post (usually February or March), use the Belastingdienst’s standalone M-form software yourself or get an expat tax advisor to handle it.
An expat tax advisor costst typically €200 – €400. They often find more deductions in your favor than they cost.
What is the M-form, and do I need to file one?
The M-form is a tax return for people who became a Dutch tax resident, or stopped being one, partway through the tax year. The “M” stands for migratie (migration). You need to file one if any of these apply to you:
- You moved to the Netherlands during the past tax year (for example, you arrived in May 2025 and the form covers 2025).
- You left the Netherlands during the past tax year and lived somewhere else for the rest of it.
- You arrived and left in the same year, less common, but it happens.
The Belastingdienst usually sends the M-form to your Dutch address in February or March, once you’ve registered with the gemeente (BRP) and your tax records are linked. So if you arrived in 2025, expect the M-form for the 2025 tax year to land in your post in early 2026.
Good news for later: in your second year and beyond, you switch back to the standard P-form, which is much simpler and can be filed online through Mijn Belastingdienst. The M-form is a one-time event for most expats but doing it right matters, because mistakes here can echo through your tax record for years.