M Form 2017
You may not file your tax return in digital form if you lived in the Netherlands for only part of the year because you immigrated to or emigrated from the Netherlands in 2017. In that case, you must use Form M.
If you have received an M Form, you are required to file your return before the deadline stated on the return form. If you need more time, you may apply for a postponement by writing to the tax office (only available in Dutch) that is competent in your case. You will find the address on the tax return.
Applying for an M form
If you did not receive an M Form from the Tax and Customs Administration and you wish to file a tax return for 2017, you can apply for an M form.