"There would be fewer returns filed in January and early February and more returns filed later," he said. "January revenues would possibly exceed estimate with the excess balanced out by lower revenues in February and March."
Muchow said taxpayers most likely to delay filing next year would be those affected by the federal alternative minimum tax, or AMT.
The AMT was originally designed to ensure wealthy families paid a fair share of taxes, but since the level at which the tax kicks in has not been properly adjusted for inflation, it affects more and more taxpayers each year.
Muchow said the 2011 alternative minimum tax applies to individuals making more than $48,450 or joint-filers making more than $74,450. Unless Congress changes the law this year, the AMT level will fall to $33,750 for individuals or $45,000 for those filing jointly.
"Absent change, a greater number of middle-income taxpayers will be forced to calculate both a regular federal income tax and an alternative minimum federal income tax on their 2012 tax returns," Muchow said.
The following are set to expire at the end of the year:
Muchow said the impact of any filing delays should balance out by the end of the state's fiscal year in June, so it shouldn't affect the next budget year.
But he added some taxpayers who anticipate higher taxes in the future might find ways to book some unrealized income in 2012 to take advantage of lower rates.
State personal income tax collections are running slightly behind forecasts for the current fiscal year. Muchow said that might change once taxpayers begin taking advantage of lower 2012 rates.
"We anticipate some income tax revenue enhancement due to this type of behavior in the current fiscal year," he said.
While it would boost current year revenues for the state, Muchow said this type of behavior could hurt personal income collections in 2013.
Contact writer Jared Hunt at jared.h...@dailymail.com or 304-348-5148.