The Dutch M-form, the special income tax return for years in which you immigrate to or emigrate from the Netherlands, will be published later than usual for the 2025 tax year. Both the digital and paper versions of the M-form have been postponed, giving taxpayers and tax advisors more time to prepare the tax return.
New publication schedule for the 2025 M‑form
The Dutch tax authorities have announced that the M-form for the 2025 tax year will be released on 1 May 2026, later than in previous years. The deadline to file the completed M-form is also extended to 1 July 2026. This shift is due to the additional time needed to incorporate all the recent changes in box 3 (savings and investments income tax) into the form.
As a result:
-
The digital M-form (online) will be available from 1 May 2026.
-
The paper M-biljet will also be available from 1 May 2026.
-
The final filing deadline for this form is now 1 July 2026.
This change gives taxpayers who moved into or out of the Netherlands during 2025 extra time to accurately complete their tax return.
Why the delay?
The delay is primarily due to the complex updates related to box 3 taxation that needed to be incorporated into the M-form. Because this form must accurately reflect all relevant tax rules, including recent reforms and judicial clarifications, the Dutch tax authorities decided to postpone publication to ensure correctness and completeness.
What is the M-form and who needs it?
The M-form is a special tax return used when you move into or out of the Netherlands during the tax year. The word “M” stands for “migration,” and the form essentially combines two tax returns into one. For the part of the year that you were a Dutch tax resident, income and deductions are taxed under resident rules. For the part of the year you lived outside the Netherlands, non-resident tax rules apply.
The form is essential for anyone who:
-
Immigrated to the Netherlands (became (part-year) resident),
-
Emigrated from the Netherlands (ceased residency during the year),
-
Or had mixed residency status in the same year.
Because the M-form covers both Dutch and foreign residency periods, it can be more complex than a standard annual tax return.
Why it matters
If you moved to or from the Netherlands in 2025, you will likely need to file the M-form in 2026. Missing the extended deadline of 1 July 2026 could result in tax interest, penalties and/or delays in receiving your refund, especially if you are due a tax refund because your income and withholding were prorated across different residency periods.
Contact us for help with your M-form
Completing the M-form accurately can be complicated, especially if you have foreign income, assets, or deductions that must be split between residency periods. If you need support with your 2025 M-form, including advice on tax residency and income allocation, feel free to reach out to us and we are happy to help.