Severe delays and inconvenience for millions of taxpayers could result in 2015 if the “lame duck” U.S. Congress fails to deal soon with a list of temporary tax laws that expired at the end of 2013, the Internal Revenue Service and a key senator warned recently. More than 50 expired tax laws called “extenders” are in limbo, waiting for Congress to decide whether to renew them or not.

The longer Congress delays action, the greater risk that the tax filing season and millions of taxpayer refunds will be delayed, among other serious disruptions. IRS is well into its preparations for the 2015 tax filing season, with continued uncertainty about the extenders presenting a complicating factor. “This uncertainty, if it persists into December or later, could force the IRS to postpone the opening of the 2015 filing season and delay the processing of tax refunds for millions of taxpayers.