Question juridique clé
Whether the CHF 20,000 receivables adjustment for missing invoice/payment slips was justified
Solution extraite
The taxpayers did not credibly prove that the missing receivables were absent for innocent reasons; the adjustment remained within the authority's discretion.
Motifs extraits
Under Art. 123(1) DBG and § 127(1) StG, taxpayers must prove facts reducing tax. Given the missing documents, inconsistent explanations, and a proven unrecorded invoice, the taxpayers bore the risk of evidentiary failure.