The IRS encourages caution to those people who received a third Economic Impact Payment or advance Child Tax Credit in 2021. Taxpayers should ensure the amounts they've received are entered correctly on the tax return. Incorrect entries when reporting these payments mean the IRS will need to further review the tax return, creating an extensive delay. To help taxpayers, the IRS is mailing special letters about the stimulus payments and advance Child Tax Credit payment amounts. People can also check the amount of their payments in their Online Account available on IRS.gov.