If you received Advanced Child Tax Credit payments or a third stimulus check in 2021, keep an eye out for mail from the IRS

• Advanced Child Tax Credit payments gave parents up to $300 for each child from June to December 2021.
• People who received payments should keep Letter 6419 mailed by the IRS to help file their 2021 tax returns.
• Those who received the third stimulus check should also hold on to Letter 6475 to help file their tax returns.
• Read more stories from Personal Finance Insider.

Before the pandemic, parents with children under 17 received up to $2,000 per child on their tax return depending on their annual gross income and the age of their children.

To help parents manage economic hardship caused by the pandemic, the American Rescue Plan passed in March 2021 allowed low- to medium-income parents receive an advance on their child tax credit. The Advance Child Tax Credit (CTC) payments were received by parents via direct deposit if the checking account information they used to file taxes was up to date.

Letter 6419 has important CTC payment information you need to file taxes

The IRS is sending informational tax letters in the mail to anyone who received Advance CTC Payments. Here’s what you need to know.

Letter 6419 from the IRS will contain the total amount of advance CTC payments you received in 2021, and the exact period of time that you received payments.

You can also check the total amount of CTC payments you’ve received in 2021 by checking the Child Tax Credit Update Portal on the IRS website.

You’ll need Letter 6475 to file your taxes if you received a third round of stimulus checks in 2021

The third round of Economic Impact Payments, more commonly known as stimulus checks, were actually advance payments of the 2021 Recovery Rebate Credit. Aside from a one-time payment of up to $1,400 for individuals and $2,800 for married couples, some people may also have received plus-up payments based on their income level.

If you received a third round of stimulus checks in 2021, you’ll need Letter 6475 sent by the IRS in the mail to file your taxes this year. Letter 6475 has details about how much money you received from the 2021 Recovery Rebate Credit in 2021.

If you were eligible for a third round of stimulus checks but did not receive one, you may be able to claim a 2021 Recovery Rebate Credit and get your payment. You’ll need Letter 6475 to tell you how much of the Recovery Rebate Credit you’re eligible to claim on your tax return.

If Letter 6419, the Child Tax Credit Update Portal, or Letter 6475 contain errors or discrepancies about the payments you received, call IRS customer service at 800-829-1040 from 7 a.m. to 7 p.m. local time.