Taxpayers who already filed their 2020 returns should not amend them to take advantage of tax breaks that were created by the new $1.9 trillion pandemic relief legislation, the Internal Revenue Service commissioner, Charles Rettig, told lawmakers on Thursday, saying that the I.R.S. would automatically send refunds to those who qualify.
Mr. Rettig, speaking at a congressional hearing, was referring to a provision in the law that provides a tax exemption on the first $10,200 of jobless benefits collected in 2020 by unemployed workers whose households earned less than $150,000.
“We believe that we will be able to automatically issue refunds associated with the $10,200,” Mr. Rettig said.
According to The Century Foundation, about 40 million Americans received unemployment insurance last year.
The tax changes included in the most recent stimulus bill passed earlier this month, along with tax changes in the December aid package and the rush to disburse economic impact payments, have put severe pressure on the I.R.S. The agency said on Wednesday that Tax Day would be pushed back by a month, from April 15 to May 17, to give itself and taxpayers more time to handle returns and refunds.
The Treasury Department and the I.R.S. are also racing to develop new regulations and update systems to reflect other aspects of the March relief law.
Treasury officials said at a briefing on Thursday that they are working with the I.R.S. to develop a new online portal to disburse advance payments for the expanded Child Tax Credit, which will provide up to $3,600 per child under age 6 and $3,000 for children ages 6 to 17, regardless of whether a family earns enough to pay income taxes.
The portal will allow taxpayers to upload relevant data for midyear payment adjustments, such as the birth of a child, the officials said.
Treasury officials also said the department is working on additional guidance on how states can use money included in the relief law. That will include clarity about how states must repay relief funds if they decide to cut taxes after receiving aid.