RELATED: IRS Warns You Won’t Be Able to File Online Without Doing This First. In late December, the IRS announced that it had started to send out information letters to millions of taxpayers that had received advanced child tax credits. This form, Letter 6419, will include the total amount of advanced payments a recipient received in 2021, as well as the number of qualifying children used to calculate this amount. According to the IRS, families who received any advanced credit last year will need to file a 2021 tax return and can use the letter to figure out how much of the credit they can “properly claim” on their return.ae0fcc31ae342fd3a1346ebb1f342fcb “The IRS urged people receiving these letters to make sure they hold onto them to assist them in preparing their 2021 federal tax returns in 2022,” the agency said in a Dec. 22 statement. But for some taxpayers, this letter might cause more harm than help. Ken Corbin, chief taxpayer experience officer at the IRS, admitted on Jan. 24 that in some situations, “the letters may not reflect what the taxpayers actually received,” CBS News reported. According to the news outlet, the agency said it is unclear on how many people received incorrect letters. But Corbin said he suspects that it was only a small amount. Taxpayers who are worried that their letter may contain errors should check their account on the IRS website, Corbin told CBS. “The online portal is correct, and we encourage them to check IRS.gov,” he explained. RELATED: For more finance news, sign up for our daily newsletter. While the IRS is not certain how many taxpayers got incorrect letters, certain factors might make some taxpayers more prone to receiving errors. This includes those who moved or changed bank accounts in December, as well as people who are married and filing jointly, per CNET. According to Corbin, advanced child tax credit checks might have been undeliverable by mail or direct deposits may have bounced back from a bank if a taxpayer moved or changed banks in December. But the letter, which started being sent out in December, would likely still include this amount as if it was properly delivered. And as CNET explains, spouses who are married and filing taxes jointly would both receive a letter from the IRS. These taxpayers will need to combine the information from both letters to get the correct amount. But Mark Jaeger, Tax Act’s vice president of tax operations, told the news outlet that some families have been confused by this and only entering information from one letter, which would result in an incorrect amount. Taxpayers who are claiming the second-half of their child tax credit on their 2021 return will not receive their refund before mid-February. This is because the IRS is unable to issue a refund involving these payments before this date by law, in order to provide “additional time to help the IRS stop fraudulent refunds from being issued.” But if you file your 2021 tax return and the amount of child tax credit you claim is incorrect, it will likely delay your refund even more, according to the agency. “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,” the IRS said in a Jan. 24 statement. The agency says that most taxpayers who file a return with no errors should receive their refund within 21 days, if they file electronically and choose direct despite. “We want taxpayers to have the info they need to file an accurate return,” Corbin told CBS. RELATED: Turbo Tax Will No Longer Let You Do This, Effective Immediately.