IRS Letter 6419 and Letter 6475 important for some tax returns to reduce errors and delays. Check the mail for IRS Letter 6419 and IRS Letter 6475 to prepare your Tax Return. (Letter 6475 only applies to the third round of Economic Impact Payments.) The IRS stated information in the letters will help to reduce errors and delays. IRS started sending the letters to people who received the advance child tax credit payments and third Economic Impact Payments. The letter 6419 includes the total amount of advance child tax credit payments taxpayers received in 2021 and the number of qualifying children used to calculate the advance payments. The letter 6475 will help Economic Impact Payment recipients determine if they are entitled to and should claim the recovery rebate credit. The amount is needed to file tax return. Here is the statement from them about IRS Letter 6419 and 6475.