And the IRS also reminded taxpayers that it will have to hold refunds for those claiming the Earned Income Tax Credit and the Additional Child Tax Credit until February 15 under a law that stems from an increased focus on security.

More than 153 million returns are expected to filed in a season that extends through April 18. The deadline is extended because of the observance of the Emancipation Day as a holiday in Washington D.C. on April 17.

In 2016, the IRS issued 111 million individual tax refunds. It expects more than 70 percent of taxpayers will receive refunds. The IRS anticipates issuing more than nine out of 10 refunds in less than 21 days from when returns are received.

"We encourage taxpayers to file as they normally would, including returns claiming the EITC or ACTC" IRS commissioner John Koskinen said in a prepared statement.

The FreeFile program, available at IRS.gov, opens Friday, January. Participating companies are expected to offer free software to about 100 million individuals and families with less than $64,000 in annual income. Seventy percent of taxpayers are eligible for the program.