Reference the front page article "Shutdown could make it tough for tax-filers" Jan. 4.
There is a bigger problem than what you cited: tax payers may have delayed refunds. The bigger problem is that the IRS has not released the approved forms for filing by the deadline. Usually, the forms for filing are approved and released by the end of January, but with the government shutdown, if the forms are not approved, then one cannot even file their tax returns, as required by law, in the middle of April. That impacts the ability to even prepare your return, either by yourself or using a tax preparation service.
What happens if we don't have the approved forms? Will the tax filing date be extended? If you can't file, then the government cannot collect taxes by the due date, leading to further deficits. You can bet that the government will not stop spending even though they don't have revenue coming in.