(WJW) — Those who received a third stimulus check in 2021 should soon be getting a letter in the mail from the Internal Revenue Service (IRS).

“People receiving these letters should keep them,” the IRS said in a statement. “Do not throw them away.”

The letters are meant to help with your 2021 tax returns by more thoroughly explaining how to claim your economic impact (stimulus) payments — which aren’t taxed but still must be claimed.

Are you entitled to a recovery rebate credit and should you apply for one? The explanatory letter is going to walk you through the process, telling you how much stimulus money you received, including any “plus-up payments,” and any extra dollars still owed to you.

Worth up to $1,400 for recipients and any dependents, third stimulus checks started being sent out last March.

The letters are supposed to start being sent out by the end of January. A separate letter is also being sent out to those families who received child tax credit payments last year.

Find out more about filing your tax returns, which are due on April 18, right here.