The Internal Revenue Service is among federal agencies affected by the US government shutdown, and a protracted gridlock could complicate tax filings.

The agency is operating with only 12.5% of its workforce, or fewer than 10,000 federal employees, according to CNN.

U.S. President Donald Trump speaks to the media as he returns from Camp David
U.S. President Donald Trump speaks to the media as he returns from Camp DavidReuters

During a shutdown, the IRS typically doesn't perform audits, pay refunds or offer assistance to taxpayers if they have questions — especially outside of the filing season.

Tax filing season usually begins in mid-January.