The delay in the tax-filing season is a result of the 16-day partial government shutdown at the beginning of October, the agency said. The IRS said it needed additional time to program and test tax-processing systems in the wake of the shutdown.
Tax-filing season had been scheduled to begin Jan. 21 and now will start no earlier than Jan. 28 and no later than Feb. 4, the IRS said in a statement.
"The government closure came during the peak period for preparing IRS systems for the 2014 filing season. Programming, testing and deployment of more than 50 IRS systems is needed to handle processing of nearly 150 million tax returns. Updating these core systems is a complex, year-round process with the majority of the work beginning in the fall of each year," the IRS said.
The shutdown affected about 90 percent of IRS operations and put the service nearly three weeks behind in getting ready for the next tax-filing season.
"Readying our systems to handle the tax season is an intricate, detailed process and we must take the time to get it right," said acting IRS Commissioner Daniel Werfel.
The IRS said 2013 paper tax returns won't be processed before the start date, which will be announced in December, and that taxpayers filling electronically will get refunds much faster than paper return filers.
April 15 will remain the deadline for filing tax returns under federal law.
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