(NEXSTAR) — Tax season officially began on Monday, Jan. 24. As you prepare to file your 2021 taxes, you’ll want to watch for two letters from the IRS to make sure you get the money you deserve. This year, the IRS is mailing two letters—Letter 6419 and Letter 6475—to qualifying Americans.

The first applies to the Child Tax Credit Payments. According to the IRS, Letter 6419 outlines the total amount of advance Child Tax Credit payments you received in 2021 and the number of qualifying children used to calculate the payments. You can see a sample Letter 6419 here.

Regardless of whether you are or aren’t eligible for the credit, the letter instructs you to file Schedule 8812. This will help you claim your remaining credit or determine if you must pay back any of the payments you received in 2021.

You can also review the advance payments you received online. If you were eligible to receive payments but didn’t, the IRS says you can claim the full amount of the child tax credit on your 2021 federal tax returns. Families who do not normally need to file a tax return should do so to receive their payments.

The other letter, Letter 6475, relates to the third stimulus payment and includes how much you received in stimulus money last year. This includes any plus-up payments, which were additional payments the IRS sent to people who received a third stimulus check based on a 2019 tax return or information from the Social Security Administration, Railroad Retirement Board, or Veterans Affairs. Plus-up payments were also sent to people eligible for a larger amount based on their 2020 tax return, according to the IRS.

Letter 6475 applies only to the third Economic Impact Payment, which was issued in March and distributed throughout the year. You can use this letter to determine if you can claim the Recovery Rebate Credit on your return.

While most eligible Americans already received their payment, those who are missing theirs should claim the recovery rebate credit. Stimulus checks aren’t taxable but do need to be reported when you file your taxes. Taxes need to be filed by April 18 this year.