The Tax Office offers the possibility of getting help with tax returns. This also applies to people living in Germany or Belgium who have to file a tax return in the Netherlands. When ticking help with a C- or M-iljet, the phone number of Belastingdienst Buitenland comes up: +31 55 5 385 385. This way, a telephone appointment or appointment at a Tax Office can then be scheduled.
More information can be found on the Dutch Tax Office’s website (Belastingdienst; only available in Dutch.)