Facts
Otto S. was affiliated as a self-employed person to the compensation fund of the canton of Zurich from 1958 to the end of December 1978. In 1980, the fund obliged him to pay the personal OASI/IV/APG contributions for the years 1976 to 1978 based on tax returns. In 1986, the cantonal tax authorities found that Otto S. had concealed part of his income for the tax periods 1977/78 and 1979/80, resulting in a tax reassessment and fines. In 1987, the tax authorities communicated the revised incomes for the years 1973 to 1976 to the compensation fund following a supplementary and penal tax assessment procedure for the cantonal tax. On this basis, the fund determined new contributions for the years 1976 to 1978.Considerations
The Federal Tribunal ruled that the notion of "assessment following a tax evasion procedure" within the meaning of Art. 16 para. 1 OASIA includes not only an assessment of the federal tax, but also an assessment of the cantonal tax. Thus, when a supplementary assessment procedure is opened, it must first be verified whether there is a final supplementary assessment for the direct federal tax. If this is not the case, the determining income for the calculation of the contributions must be established on the basis of the final supplementary cantonal assessment, provided that it has been carried out…