64:26:02:05.  Supplementary return required upon subsequent increase in income -- Exception if increase results from departmental adjustment. When the taxpayer has filed a return with the department for the tax year and a subsequent increase occurs in the taxpayer's net income or taxable income for that tax year, whether because of audit and adjustment by the United States or otherwise, the taxpayer shall file a supplementary return with the department for the tax year in which the income was earned. The return must be filed within 60 days after the final determination of the increase in income. A supplementary return need not be filed if the increase in the taxpayer's income is the result of an adjustment in the original return by the department.

          Source: 4 SDR 35, effective December 22, 1977; 13 SDR 129, 13 SDR 134, effective July 1, 1987.

          General Authority:SDCL 10-43-42.1.

          Law Implemented:SDCL 10-1-33, 10-43-10.1.