USA Today reported the partial government shutdown, caused by a deadlock in negotiations between President Donald Trump and Congress over border security, could cause the Internal Revenue Service to delay issuing refunds to taxpaying Americans.

The agency calls issuing tax refunds a “non-excepted” activity, which is performed by government workers who are being furloughed because of the shutdown.

The IRS generally doesn’t issue tax refunds during a shutdown. Only about 1 out of 8 IRS workers work during the shutdown. That’s fewer than 10,000 employees.

Several tax returns have been called “Necessary for the Safety of Human Life or Protection of Government Property” and plans for what can and can’t be done during the partial shutdown can change, USA Today reports.

There will be more pressure on President Donald Trump and lawmakers to strike a deal now that Americans won’t receive their refunds.