Can I appeal my Swiss tax assessment?
Yes. If you believe your Swiss tax assessment is incorrect, you can usually file a written objection (Einsprache). In most cases, you must submit your objection within 30 days of receiving the assessment. The objection should explain why you believe the assessment is incorrect and include any supporting documents. Missing the deadline may mean the assessment becomes final, even if it contains errors.
Dear taxum, my tax assessment just arrived and something looks wrong. What can I do?
You have 30 days. That is the part most people do not realise until it is too late.
From the date you receive your assessment, you have 30 days to file a written objection - an “Einsprache”. The deadline is strict. Once it passes, the assessment becomes final, regardless of whether it contains errors.
The objection needs to be reasoned and supported with documents. It is not simply a matter of saying the number looks too high.
I have seen assessments that were entirely correct. And I have seen assessments with genuine errors - wrong income figures, missing deductions, misallocated foreign assets - that went unchallenged simply because the letter sat unopened for too long.
The assessment is not the final word. But only if you treat the 30 days as the deadline it actually is.