Kernrechtsfrage
Whether the prerequisites for a back-tax assessment were met under Art. 151 DBG and § 170 StG.
Extrahierter Entscheid
Yes. The 2009 employer letter constituted a new piece of evidence revealing an under-taxed wage component in the 2007 assessment.
Extrahierte Begründung
Back taxes require a final, too-low assessment caused by facts or evidence unknown at assessment time. The notice from the employer disclosed a previously unknown wage component; the tax authority could rely on the taxpayer’s declaration and was not required to uncover the hidden component earlier.