On 9 November 2011, the ATO released draft Taxation Determination TD 2011/D11 for public comment by 9 December 2012. Its full title is "Income tax: when is the shortfall interest charge incurred for the purposes of s 25-5(1)(c) of ITAA 1997?"
The draft answers the question posed in the title as follows:
"Shortfall interest charge (SIC) is incurred for the purposes of s 25-5(1)(c) of ITAA1997 in the year of income the Commissioner gives a taxpayer a notice of amended assessment. This is the case even if the SIC liability is notified separately from the notice of amended assessment, or if the SIC is unpaid at the end of that year of income (for example, because the due date for payment of the SIC falls in the next year of income)."